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Digitizing and Geocoding Old Maps?
alobar72 writes "I have quite a few old maps (several hundreds; 100+ years old, some are already damaged – so time is not on my side). What I want to do is to digitize them and to apply geo-coordinates to them so I can use them as overlays for openstreetmap data or such. Obviously I cannot put those maps onto my €80 scanner and go. Some of them are really large (1.5m x 1.5m roughly, I believe) and they need to be treated with great care because the paper is partly damaged. So firstly I need a method or service provider that can do the digitizing without damaging them. Secondly I need a hint what the best method is to apply geo coordinates to those maps then. The maps are old and landscape and places have changed, it maybe difficult to identify exact spots. So: are there any experiences or tips I could use?"
Why not use a handheld scanner and some stitching software?
Use a digital camera. It doesn't even have to be super high MP. Just stitch the images together.
Proper lighting, focus, tripod, and a large enough flat surface should produce pretty close to scanner results.
Faster than the scanner and stitching.
I suggest you contact the restoration experts in major museums for (1) advice about preservation, and (2) how they go about their own digitizing projects. I read a fascinating article about the digitization of many medieval parchments, but I don't recall the particular museum involved now.
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I have a map of the U.S. - its actual size. The legend says "1 mile = 1 mile".
People ask me where I live and I say, "E4".
It must have been something you assimilated. . . .
I guess you should have used a more up to date map.
If so, give USGS a call. They may well be interested in helping you with this and obtaining data from the maps. I can't say for sure, of course, but this is the sort of thing they do. When it comes to map data for the US, they are the go to guys. Call them up, tell them what you've got and what you want to do, see if they can put you in touch with someone in their agency who'd be interested in helping.
Not ALL features will change. Once you get them to a scale you can use, use three points on both maps, such as mountain peaks or a particular coastal feature. When overlaid and aligned, it should be fairly accurate.
I'd suggest appealing to Google or the brothers that did tapestries for the Met. What are these maps of? Is there a society for the place that they cover where you could appeal for funds under the pretense that you publicly release the maps?
Assuming all those avenues are exhausted, let's look at some cheap and dirty DIY methods. I'm assuming you've got a MP digital camera. There are sub $100 ten megapixel cameras out there but don't get anything with a fancy digital zoom. Next you'll need mosaicking software or if you're into software, you can try your own implementation of the KLT algorithm.
First off, practice all of this on layed out newspapers while developing your preferred methodology.
Your cheapest and most haphazard option is going to be lay the maps flat on the floor and cut a length of string with a washer on it (two to three feet?). Try to use brightly diffused lighting so that is normalized in the mosaics with no shots of your shadow over the maps. Now this is backbreaking but hold the camera flat over the map with the string extended in front of it so you can keep the distance to the map consistent. Don't angle the camer as this will slightly distort that tile and hinder the mosaicking. Put plastic bags on your feet if you need to walk on the maps. Take a picture, move a few feet in a grid style, take another picture. Rinse, wash, repeat until you have images covering all of the map. Collect the images and put them on the computer and verify the mosiacking works before preparing the map for storage forever.
A better method would be similar but to construct a large wooden rectangular box with plexiglass as a top so that you can fit this structure over the largest of the maps. Then cut holes in the plexiglass so that you can set your camera at a plane level to the surface of the map into the plexiglass. You might want to put an adapter on your camer that allows the lens and flash to be free of obstruction. You could make the tiles more uniform and save your back some work but you need to build and buy the materials for the structure. I think this is more time consuming but your best bet and will allow you to gather more images with less distortion.
Above all, remember to save the original images! It's probable that later better algorithms will be developed to normalize the images, remove distortions, light problems, shadows and increase clarity on your overlapping sections. If you do the plexiglass route, you could manufacture it so that every bit of the map is photographed three or four times.
Not professional, not flawless but cheap and dirty. Hope this helps.
As for the geocoding, what are the maps of? You should actually check out the feature extraction of the KLT algorithm and consider using that methodology for syncing these up with maps. That will require human intervention though to identify the features, I'm sure.
My work here is dung.
I know that the US military has some large map scanners, so specialized equipment for this task does exist.
Im going to suggest taking apart a flatbed and laying the map out on a large white surface. Then scanning the map in sections by hand, and digital stitching together the resulting image strips. This would probably be the cheapest and quickest solution (and then only you handle the maps so if something gets damaged, its no-one else's fault). As far as Geo-coding, im not familiar with anything along those lines, so your on your own... however "best guess" approach will probably be sufficient for projects needing moderate accuracy. You can probably find tutorials on taking apart scanners for similar use (not exact but this is DIY remember) over at www.hackaday.com they have some really interesting projects there, and iirc one that involved a disassembled scanner for one use or another. On any note, good luck with your project... wishing you success!
I actually have a strange fascination with old maps myself, and regularly crawl the web for all kinds of antique maps. One overwhelming commonality I have noticed is that even recent maps can often be wildly wrong. So for example, an 1600ish map of Europe will be so wildly inaccurate that you would only be able to pick one point on that map to apply geolocation specific coordinates, the rest would not match up. So, I know I didn't answer your question, but I just think that unless they are accurate maps, it would be a very hard challenge.
"It's ok, I'm completely secure as long as my iron is off"
I know that some University libraries are equipped to handle this kind of work. In particular, the Knight Library at the University of Oregon has a department dedicated to digitizing old works like this.
You might want to find the local university cartography or geography department. They will probably already have a method of doing this, or at least could point you to someone who does. Here's an example: http://mapmaker.rutgers.edu/ and their historical maps: http://mapmaker.rutgers.edu/MAPS.html
-molo
Using your sig line to advertise for friends is lame.
It can do the orthorectification along with the blending and exposure compensation. You could even do it as an HDR to really preserve it!
The Universal Transverse Mercator (UTM) co-ordinate system will be the easiest to apply to your maps. I would start by researching "world files." http://en.wikipedia.org/wiki/World_file
Turns out a lot of pre-GPS maps are not that accurate.
OP didn't mention if these maps have lat/long data in them. If so then you are good to go with using Google Earth and it's KML format to describe the map and it's inherit location on the globe using lat/long points of known locations or map end points.
If you do not have lat/long you may need to match up the map with an existing map using something like google earth and overlay it until it lines up properly. Then you can get the end points for the map and, again, use KML to describe where it should reside.
Really, history majors will love this stuff. Giving them maps and a concept of Google maps overlays for real time comparisons to modern maps will likely be a capstone project for some undergrad.
A few years ago while working for the State of Wisconsin's Board of Commissioners of Public Lands we worked with the University of Wisconsin: Madison to get all of the original land plat maps of the state digitized, indexed and search-able. Same type of deal, huge maps on really old paper that had to be vault kept with humidity and temperature controls.
-Rick
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
Focus on the preservation of the imagery first, obviously, because once that's gone it's gone forever.
The cheapest option is a large-megapixel digicam known for good image quality. SLR would probably be a good bet. You can take multiple images and stitch them together without too much trouble, so you can get reasonably fine detail with a little work even with a $200 consumer camera. Or, alternatively, hire a professional photographer and have him/her take really high resolution photos of the maps. The advantage of this approach is that you don't have to take the maps anywhere or do anything special with them. Just lay them out on a low table or the floor and align a camera over them, and take heavily-overlapping shots.
Large-format scanners might cost some serious coin even to use for a one-time project like this, but would probably yield better results with less effort.
You might check with local companies that deal in maps and cartography, they might be able to recommend ways of saving the imagery, and some might even offer to help out if the maps may be of commercial interest (they might even share the proceeds with you in addition to giving you high-res digital images).
But I'd say if the maps are truly delicate, your first focus should be to take the highest-resolution images you can of them now, even if it's multiple images per map that need to be stitched. That way, you have *something* preserved in case one or more of the maps is destroyed or deteriorates further before you can preserve it.
If there are particularly interesting features of the map, use the MACRO feature on your camera - most stitching programs can integrate images at different scales and preserve a lot of detail. I used the "Hugin" pano toolkit (free) to stitch together about 100 random photos I took at the top of the Eiffel Tower into an impressive contiguous 360 panoramic shot, and it was literally a "here are the pictures, figure it out" process. The pictures were all taken at different zoom levels, different angles, and all sorts of issues, yet it looked like a Google Street View 360 image. This was 5 years ago, I can't imagine how much better the technology is today.
The geolocation shouldn't be all that hard - it's a matter of choosing a few points on the map and identifying their coordinates accurately. Of course, if there are few/no reference points it gets a lot harder. http://www.openstreetmap.org/ is a good starting point to a group that does free, open-source mapping. They or some of their related sites might possibly have a tool that does what you want. Also, a professional cartographer may be able to help you out as well.
"This post contains words, known to the State of California to cause thought. Wash brain thoroughly after reading."
This'll sound stupid, but call your local municipal government. My city, for example, has a nice big scanner that works well for old and well-worn maps. They might even scan the maps for free, esp. if they can keep copies (if your maps include their jurisdiction). Your other option may be to contact a blue-print or architectural printer - even if they don't offer this sort of service, they may know someone in your area who can help.
Never underestimate the potential of Human stupidity. -Heinlein
Another possibility would be a really high resolution digital camera. My wife (historical linguist) has dealt some with manuscripts, and that was their method of digitizing them for further study. OTOH, she's not a museum curator or archivist; they probably have even better methods. If you want to do it right, talk to a curator or archivist of some sort. They deal with much more fragile and much more valuable documents on a regular basis.
I don't have any good ideas to contribute about the geocoding, unfortunately.
SIGSEGV caught, terminating
wait... not that kind of sig.
Quite a few = 30, or
Quite a few = 3000
Different approaches will make sense at different project scales.
First, ask on the OpenStreetMap mailing lists. There's lots of us who've done this kind of stuff before, and we'd be really pleased to help. I collected, scanned and rectified the Ordnance Survey's New Popular Edition - a complete set of England and Wales maps from the '50s, now out of copyright. It's all available in OpenStreetMap as a background layer and loads of people use it for adding rural roads, rivers, placenamese etc. Others are scanning other old Ordnance Survey series right now. Seriously, we love this kind of stuff. (#osm on OFTC can help too.)
Secondly, GDAL is definitely your friend. It's the most amazing set of command-line tools for rectifying and reprojecting data. gdalwarp and gdal_translate are probably the two you'll use most.
Take it to a high volume blueprint company ("your city name" Blueprint, Dodge Plan Room, etc.)
Most have continuous feed scanners designed for E size drawings or larger, and the one next door sells 6'x10' city maps they print on site.
As far as the geocoding, I'll leave that to those more qualified.
If not a museum, also try contacting your local university or historical society. They may also see value in your goal, and like the museum they might also take steps towards physical preservation in addition to doing digital archival.
As for doing geocoding, you might try asking those type of questions on the Google Earth forums. From what I understand, Google Earth already has some nice tools for integrating different layers of map overlay data, and it should work great for what you're trying to do.
I'd take a look at some of the projects at Metacarta labs (http://labs.metacarta.com/). I worked there for a couple years, and they do a lot with converting old maps into digital, interactive versions. If you get in touch with them, they have some super-enthusiastic people who can give you great advice.
1. Digital SLR camera, pick your flavor, I like the Canon EOS 5D Mark II
2. Tripod to Stabilize the camera and allow for constant distances & angle (right angle) when shooting... Your going to want something with a center column so you can adjust the hight without adjusting the legs.
3. Some kind of ambient lighting to prevent shadows and so you can shoot at a low ISO (less noise) and a high f-stop
4. Stitching software like this: http://cvlab.epfl.ch/~brown/autostitch/autostitch.html (If you are are using the tripod and keeping a constant distance any photo program should do.
Put map on a surface, take many photos, stitch, takes some time for the first one but it will be quick once you get going.
Old maps and geo coordinates...maybe a Google maps or earth API like this: http://code.google.com/apis/maps/documentation/overlays.html
What type of maps are these?
Many professional-style maps in the USA -- e.g. quad sheets, parcel/tract maps, etc. -- will have survey markers indicated. Ideally these would be set benchmark disks with longitude/latitude noted. Many maps also mark boundaries of townships, sections, and half- and quarter-sections, locations of which should be available from the local municipal authorities.
These sort of well-defined points are probably your best bet for empirical location, but if your maps are 100 years old the coordinates may not be precise enough for digital overlays. In the end, you may well be forced to manually align your maps with something more modern.
... that can handle just about anything. I had a very large historical map/timeline (maybe 1m x 2m) scanned by a professional service, and they did a very good job. This was years ago. I would think you could find someone in your part of the world to do it.
I also posted here to say that I think your project is a very worthy one. Good luck!
Take photographs of them and put them on the internet. Google will automagically index them and add them to their street maps in real time.
Like the beaver, it's just Dam one thing after another
Google for GeoTIFF and spend some time here
Buy or borrow a high-end DSLR. Lay your maps out and provide good lighting (avoid using the flash). Because the images you produce will contain a lot of hard lines, any decent panorama software will stitch them together beautifully. I recommend Hugin, which is free. PhotoShop CS2 or better, if you have it, also does a really good job.
Feel free to send me a copy. I love old maps.
I've calculated my velocity with such exquisite precision that I have no idea where I am.
Up close any camera will have significant distortion, way less resolution, and be much harder to control in terms of lighting / contrast / brightness.
It might sound good and easy, but for anything archival it is such a bad idea. been there, tried that, went back to a scanner solution.
Find a location that has a sheet feed scanner, put your map inside a scanning sleeve, then put it through the machine. Depending on the size of the scanner, you can scan practically anything flat.
I scanned 100+ historical maps this way during my summer internship at WVU for the library. I used Photoshop to bring them in, then exported as a .tif. You can use the .tif along with ArcMap to georeference the figures to an aerial image.
Large format scanning (not just taking digital photos) - you have two options...
1) Any drafting reprographics place should have a feeder style scanner that can duplicate blueprints, posters, etc. But this method is not great for fragile source material.
2) My company has blueprint scanners, and one of these:
http://www.crusedigital.com/cd_main.asp
The bed moves under the lens allowing a 150 megapixel 2D scan of a 3D object. We have scanned lots of artwork and antique maps on this machine.
Once you have a digital image you can make this into a GPSr map file. Tutorial here:
http://www.gpsinformation.org/adamnewham/article1/gpsmapper.htm
Sounds like an interesting project... Good luck!
PS - I have to agree with earlier poster - lack of accuracy on the original map will skew your geolocation coordinates... Assign as many know geocoordinates as possible to you images.
Hi there, I am a spatial guy so thought my 0.02 may be worth something. I am not too sure about digitising them, maybe a print shop or as suggested in other posts you could talk to your local university geography department or a government mapping agency
Once they are digital though you need to georeference them. As mentioned in the title of my post, it is easiest to use GIS to do this and you can use QGIS with relative ease. Install it using osgeo4w on windows or the ubuntu ppa for qgis. Alternatively if you have a license then use ArcGIS. If you have a map of the underlying roads for the maps you are digitising then what you do is find points on the roads and match them to points on the scanned images, this provides data for a transformation and will shift the map onto your coordinates.
like phosphorescent desert buttons singing one familiar song
Find a service provider or museum with a digital Cruzcam. They are a copy stand with an integrated camera/scanner system meant for exactly what you need.
Madcow
I used to have a sig, but I set it free and it never came back.
I spent a summer doing this in grad school for the Vegetation Type Mapper project at UC Berkeley. I'm not going to lie to you--it was a ton of work. But the results were cool. The site has all the old maps georeferenced, plus ways to download them.
Needless to say, the library was involved in the project, as was a giant scanner. We relied on ERDAS Imagine software to georeference the old maps to current USGS base maps. There was also a lot of accuracy assessment involved to make sure we minimized error in the georeferencing process. Probably one of the trickiest parts was making sure the old landmark you were using as a control point had not substantially changed in the intervening decades.
My professor and her colleagues published a paper detailing the project.
Per Square Mile, a blog about density
you could try companies which sell historical mapping e.g. landmark group http://www.envirocheck.co.uk/envirocheck/about_us.jsp their business is based on historical mapping and georeferencing and they may even be interested in paying for the data if they can resell it?
Others seem to be describing some good solutions to getting the map scanned, so here's how to geocode and rectify the image using the open source Grass GIS software:
Step 0:
- You need to have a location already created in grass, with some contemporary data in it (physical features, roads etc where there's some concurrence with the map you're trying to geocode). The projection you've used doesn't matter much - a later step is going to be rectifying (ie distorting) the scanned map to match the projection of the digital map. The created location does need be at least as large as the scanned map (ie if the map is everything in a 5 km radius of some town, the grass location also needs to encompass at least a 5 km radius of the same town).
Step 1:
- Come up with a list of features/points which exist on both maps. Depending on the scale of the map, this could be intersections of specific roads, locations of towns, peaks of mountains etc. You're going to need an absolute minimum of five points for the rectification process to have any chance of working; more than fifteen is much better. Try and select points which are unlikely to have moved over time (coastline or river features for example). In grass, mouse over each point and record the coordinates.
Step 2: import the scan
In grass, do: r.in.gdal input=[path to scanned file] out=[Mapname] location=templocation
Quit grass
Step 3: target, point, rectify
Open grass, but this time in the 'templocation' you created in step 2
i.target group=groupMapname location=[modern map location name] mapset=PERMANENT
i.group group=groupMapname in=Mapname
d.mon start=x0
i.points groupMapname
d.mon will open a window; i.points will display the scan in it. Select the mapname in the dialog that appears, then one by one select each of the points you've identified as having concurrence with the modern map. In the terminal window, enter the coordinates for the point taken from the list you created in step 1. When done marking points, click 'quit'.
i.rectify -a group=groupMapname extension=_1 order=1
Depending on the size of your map and your processor speed, this bit may take a while. When done, quit grass.
Step 4: admire output
Open grass in the modern location. The scanned map will be available as a raster layer for display. The scan will have been rectified so the map matches the projection of the modern map layers - ie you'll be able to see what's moved and changed, and what exists now that didn't then etc. There's other grass commands which will help you convert features of interest (rivers, roads, contour lines, whatever) into vectors if you really want.
If all this seems too hard, have a look at qgis - also open source mapping software; it's more gui-oriented and I know it has a georectifying plugin. I've just never used it.
Good luck.
Is this possibly a treasure map? is that why you need to overlay it? I want in.
There are a few makers of large-format scanners. Océ is one. http://global.oce.com/products/wideformat/technical-documents/scanners/default.aspx
These are not cheap, or common. They are likely found in places where maps, charts, technical drawings, or similar are printed on large-format printers. I would be asking friends who work in government offices or land-planning areas whether they have a large-format printer (and an associated scanner) somewhere, and then see about arranging a "side-job" out of business hours.
The scanned images are quite large, so expect to also bring several CDs or DVDs to transfer the files.
Looking at space, radio, science and computing from a 'down-under' amateur enthusiast perspective.
If you do the math, a 1.5m x 1.5m map at 100dpi (screen quality) is only ~34,810,000 pixels. You can capture 40 million pixels with a modern medium-format digital camera. Of course, there is no requirement that you use a single photo. With a good tripod and a typical 'point-n-shoot' or DSLR camera, you can stitch multiple photos into a single high-resolution mosaic.
Saw a great presentation at OSCON a few years back about the massive digitzation effort undertaken by David Rumsey (http://en.wikipedia.org/wiki/David_Rumsey): See http://conferences.oreillynet.com/cs/where2005/view/e_spkr/1867 -- Drew a well-deserved standing ovation.
In the course of the talk, I think he said that he'd scanned the first 10,000 maps (though even 1,000 sounds ridiculous -- maybe it was 1,000) before hiring assistance.
Of course, he had more money to play with, so he probably had a pretty big scanner ;)
timothy
jrnl: http://tinyurl.com/c2l8yr / foes: http://tinyurl.com/ckjno5
Several people have mentioned good resources (museums, local government, geography dept., etc.). I'd add university libraries to that list (especially the maps or special collections departments). But the most important thing is location. Since you don't want to move the maps more than necessary, and if the maps are of your local area, then the library/museum/government in your area will be most interested in them.
For geocoding the maps, I think you'll need to figure out what you're going to do with them. If you want to do overlays in Google Earth, then using KML will probably be the best. If you want to use some other GIS software, then whatever formats it accepts, etc.
Hi, I'm a panoramic photographer, (I have shot panoramas up to 18 gigapixels in size, which currently seems to be a world record) so I hopefully am speaking from experience. What you want to do is basically shoot a panoramic image of your map.
You should situate your map as flat as possible, and shoot photos of it from a perpendicular point of view - best to hang it on a wall I guess. In the case of a very fragile map, sure, you can lay it on the floor. Take care to light it evenly.
You can then use PTGui (my favorite panoramic stitching software by far - only a satisfied customer talking) to stitch the images together into one perfectly seamless image.
Some key things to remember are to keep the map as flat as possible. A long lens is probably better, but you can use a macro lens also.
PTGui has a very handy feature called "viewpoint correction" which can join different images *of a flat surface* together, even if you didn't shoot these images from the same point (this is useful for panoramic photography when we want to capture the area below the tripod). In the case of shooting your maps, this will be very handy indeed.
Feel free to contact me via my website's contact form (360 cities dot net) and I can help advise further if you want.
good luck,
Jeffrey Martin
Contact a local Licensed Land Surveyor. We are in the business of coordinating maps and making sure they are properly referenced. We also know the difference between NAD83 and NGVD29. This and the other coordinate system conversions and the proper use of scale factor in SPCS (State Plane Coordinate Systems) is something we do every day. Plus, most of us are really into local history and could possibly show you some other really neat uses for that data. Historic societies are always looking for ways to map past events. When speaking with a Surveyor, we can usually know what the practice for a given time period was. There are three different lengths for a foot that I have come across working. International Foot (not used in surveying, but sometimes engineers use the wrong foot), US Survey Foot (standard) and the Philly Foot. Philadelphia has a different set of standards for how a long a foot is, depending on what part of the city you are in and what you are trying to do. This is not something most historians would accurately pick up. Surveyors will. We also know who was the good and not so studious Surveyors in the area and what tricks each used to mark corners, turning points and reference markers. A local Surveyor in the area the map is of would be very interested in helping you with your work. He/she may have already done the heavy lifting for you. We have to trace maps back as far as possible, so sometimes (I am in New Jersey) we have to go all the way back to the Proprietors to get maps so that we can run lines that control our current work.
Long story short, if it deals with cartography or local surveying, seek a professional Surveyor.
One Token Ring to Rule them All, One Search Engine to Find Them, One WAN to bring them in, and TCP/IP Bind them...
Two or three years ago the New Yorker ran an article about digitizing a large tapestry. As I remember the tapestry was laid out on a floor, and a high-resolution scanner was moved over it on a framework of some sort.
This took a while (days or weeks) and the fabric, responding to changes in temperature and moisture, would slightly moved between the times when different sections were digitized. Reconstructing the original appearance of the tapestry in the digitization became quite a problem
This seems to resemble your problem in several aspects.
The article describes how two mathematicians solved the problem.
Though it concentrated more on the human side of the issue than the technical, it still contained a few hints as to how they did it.
I'd suggest reading that article to see what you can glean. At the very least it can provide with some names to use either for a literature search or to contact directly.
A hint is that the tapestry featured a unicorn, and that word was probably in the title of the article.
If you have trouble locating it, try writing me.
I heard David Rumsey speak at the Long Now Foundation. He has a large collection of historical maps and wanted the ability to share his library with a broader community. He decided to digitize them and make them available to the public. He has also done work with geo-coding old maps and overlaying them current maps to either highlight changes in topography or errors in original map making. It sounds like his efforts encompass what you're trying to achieve.
I'd suggest reaching out to him or his organization to find out how they do their work... or maybe they can help.
http://www.davidrumsey.com/
I have done this for a grant-funded historical map digitization project at a university library. We used a $40k large-format scanner (from Betterlight) which can scan the whole item laid out flat. Trying to stitch together camera images will result in distortion across the image—if you didn't need to distort it, you wouldn't need special software to do it; you could just line the pictures up.
But even once you have image files, there's about zero chance you can just replace Google Maps' tiles with your own and expect geotagged stuff to line up where it should. If you have a finite number of places of interest, you could manually locate them on each map and then try to distort each map to align, but if you expect arbitrary geolocations to need to be right, give up. Non-satellite/GPS-based maps are examples of practical cartography, not theoretical. They will be even less perfect than you think, no matter how professional they appear. Or do what we did: keep the geotag display on Google's maps, but show your historical map of the same general region side-by-side and allow the user to calculate the precise correlation in his own brain.
I've listened to the person in charge of archiving at the Library of Congress who handles such things, as do many other libraries. They have developed a lot of techniques for handling and dealing with large items, including restoration. I'll bet the British Museum has a similar map department.
My bet is they have information on this at their website.
I dont know if this has been mentioned but Grass GIS the open source GIS program , has a georectification module that you can use to add the proper coordinates. Here is a page of the manual for your perusal.
National Geographic did an article on The Mannahatta Project, which did the same thing -- digitized old maps, then matched up known reference points to map them into modern map overlays with GPS coordinates. It also provides some background on why this is such a cool thing to do.
I've abandoned my search for truth; now I'm just looking for some useful delusions.
Just a pedantic little thing -- as a geomorphology instructor, I can tell you that rivers and coastlines are very, very likely to have changed. Check out pretty much any river mouth in Victoria, Australia, or any island off Maine, US in google earth vs google maps satellite mode for examples of how much they can change inside of just a few years. If something catastrophic has happened (big storm, big earthquake...), huge changes can shift the coastline inside of hours.
If you're going to use geomorphic features for your geocoding, find out what's most stable in your region (keyword search academic journals for geomorphology + your location + change and see what doesn't pop up, or ask a local university geo prof). Vegetated topography can be pretty stable over decades, especially if you only need relative shapes.
I was a little incredulous when I discovered that I could take photos with my 10MP camera in macro mode and approach the quality of my flatbed scanner.
If you can find a friend with a good digital SLR, and if you get your lighting all set right, you can probably just snap some pictures of it. MUCH faster than scanning. Then, you can use a stitching program like Hugin to bring all of the pics together and correct for distortion around the edges of the picture.
If they're that old, then you might not need the quality afforded by a really good large-format scanner.
Lots of good ideas here for doing this if you have unlimited cash. Fewer good ideas for doing it on a budget. I don't like the idea of using an SLR camera: you're going to have perspective and lighting problems which you'll need to correct in software.
Here's my idea:
1) Lay out map on large table.
2) Remove top lid from $80 scanner.
3) Flip scanner upside down, place on map.
4) Stitch the images together, or geolocate the individual images.
5) Profit!
There are several companies that do just this sort of work. The one I am most familiar with is EastView Cartographic (http://www.cartographic.com/). They have an extensive map collection already digitized. With any luck they already have digital copies of your maps. They do have a very large map collection, some of which have not been scanned yet, so even it they don't have digital copies, they may have paper copies. If not, you can send your maps to EastView and have them digitize the maps for you, but it can be expensive for a one time job, especially if the maps are in poor condition. Vectorizing the contour features takes a lot of effort even with the latest commercial software.
Trying to get something usable with GPS coordinates, you will fail. If all you want is a digital representation of the map - like, say a JPEG image - this can be done but it will be difficult.
Some insight into the process is useful. I used to work for a company involved in digital map databases. They started out digitizing maps from aerial photographs. These photographs were very high accuracy taken with large format cameras from relatively low flying aircraft. They spent years developing software to assist in the task of converting the photographs into usable digital map data. It would take considerable manual effort even at the end (after years of working on the software) to get something usable. One of the larger problems was the difference in angles between an object in the center of a photo and an object at the edge. This introduced enough inaccuracy to really screw up the maps that were produced without more manual adjustment.
Around 1999 they changed the process from using aerial photos to recording from DGPS while driving around on the streets. Overall, this greatly reduced the time required even considering the amount of time that would need to be spent driving around on the streets.
(I know what you are thinking - just use satellite photos. Sorry, they thought of that and it doesn't work. Nowhere near enough accuracy for just providing driving directions.)
While you aren't going to have the exact problem at the edges of aerial photos, you have a similar problem with the angles being different if you are stitching together multiple photographs. Mathematically, it is similar to the parallax problems in other fields. A really large format scanner would be the only way to eliminate that and it will have to be something special to avoid destroying your source material. Just about anything else will not give you anything useful.
Even after you have a scan with a large-format scanner, the problems are going to be pretty much insurmountable. The maps you are talking about are not very accurate. Sure, their error may be within a few percent, but that is going to cause things to never, ever line up against GPS coordinates. So you now have a significant task for each map adjusting the position of each and every node (intersection) and points along any curve. Old maps don't have a lot of straight lines, so there will be almost nothing but curves and every single point will need to be moved slightly.
It will take you years.
them to a library which is specialized in that:
a) they can preserve the maps
b) you get a scan back
c) and some credit
you might not realize that even though the maps might be worth something, without proper care they will slowly dissolve.
A good digital camera and a copy of OziExplorer will get you GPS'ing your way round Ye Olde Mappes on your computing device of choice. http://terraperfecta.com/frontmap.php makes calibrating the maps a point & click jobby.
There is no music - home taping killed it.
I looked into this a number of years ago when I was dealing in old maps. The best way to digitize them by far is a large format drum scanner.
-a.e.mossberg
I can't speak on how to get them digitalized, but once you do, look to the web to get others to help geocode and get them into shape for overlays. Put them online in a liberal CC license and invite other people to use them. Given the popularity of google maps and the community that's grown up making mashups and apps, I'd be willing to bet there already existing communities of people good at, and interested in, doing this.
In addition to the posts suggesting a camera, if you can project a regular grid of light over the map when you photograph it, it will be VERY helpful to compensate for any distortion caused by the digitization.
In fact, with a good grid you don't even have to totally flatten the map, as long as you get enough pixels to pick up the detail thruout the photo. (You can take two or more photos from different angles if need be.) Software can then analyze the grid and appropriately scale the areas of the image.
(And go ahead, while you are set up, double up on photos, one with the light grid and one without)
You could always try to contact archive.org. They are normally very interrested in helping out. At least they have a lot of experience with scanning old books.
We deal with old data with weird and sometimes unidentified projections fairly often. You will need at least some landmarks, though. The larger the scale, the more you will need. The more complex the projection, the more landmarks you'll need. With really old maps that are hand drawn and don't match a distance scale (pre-17th century) you're probably out of luck even if it's a local street map.
Astronomical software to deal with converting between projections is typically open source, but the learning curve is steep. Don't even think about using commercial image editing software. Even if you think it might be doing things right, you'll never be sure unless you're writing your own plugins.
Support SETI@home
Try to get a copy-stand[ebay] (possibly also named as copy stand).
Either ask the library (if you're in a big city) since they're always interested in getting their hands on anything. Or, as others suggested, find a local university that has a geography or geomatics program - they'll most likely have the expertise and tools to get it done.
As for georeferencing, I've only ever done it with ArcGIS 9, and I don't think you'll want to pay for that, but any self-respecting university will have copies of it on their computer. They may even have historical imagery from the past 60-70 years that'll help you line the stuff up.
Try Contacting www.digimap.gg. They have a lot of experience with scanning old maps and warping them to fit current mapping. They also have a (very) large format high quality scanner which should cope with any map that you have.
Talk to them nicely and they maybe able to help you at a very reasonable price. However they are located in Guernsey, which may not be convenient for you.
Hi,
Check out http://makeit.digitalnz.org/, there is a forum for asking questions if the current batch of answers aren't sufficient. They don't seem to mind questions from abroad. I know a project in the Middle East that asked a question about this sort of issue on there.
For the second operation -- georectifying scanned images -- Map Warper is a great tool:
http://warper.geothings.net/
It will let you rectify map images by placing control points. Maps can be made public so you can get help with this task from friends and strangers. Finally, you can export to PNG, TIFF, and WMS.
I would build an x/y tram and mount a hd digital camera to it. Using a couple of hacks on the camera should be able to remotely trigger it from a computer program. Given stepper motors on the x/y you could control the position of the camera. This setup could be mounted over a table and the map could just lay there. Then do as others have suggested and use stitching software to put the images together.
As part of my job I work with GIS information on a daily basis. I would say the largest issue you are going to run into is getting the map to line up with reality. I know cartographers of old did not have the tools to create accurate maps like we do today. My point being scale may not be constant over the entire map compared to reality. While you may line up one or two points you might find yourself quite off on the others. You might just have to accept it as good enough for government work. I would suggest you look into technologies like geoserver or mapserver. Consequently geoserver has openmaps built into it.
IMAGE VERIFICATION IS EVIL!
Extremely expensive, but extremely good. As a Topographic Intel Analyst in the US Marines (our job was called Topo by us), we georeferenced images a LOT. The best tool by far is ERDAS Imagine. It's best to have source maps that are already georectified, but it's not necessary. Another tool that MAY be able to take care of this is ArcInfo. It's also an expensive suite of programs, but it also works well. As far as a service that can get the images scanned for you, you may be able to contact an architect. They frequently have large (36"-48") scanners used to scan old blueprints so they can digitize them. Buying the equipment yourself is probably cost prohibitive.
Almost any map or photo will have *some* common aspect that relates to current day. Right now I am working on a project of cataloging old (back to 1937) aerial photographs of the county I live in.
I use ESRI's ArcMap, a ruler, an excel spreadsheet and some brainpower. I pick sensible coordinates (PLSS corners make the most sense when available, as well as street intersections) and then locate them on a more-or-less current day satellite/aerial overlay in ArcMap. Once I decide on my corners, I just measure the physical map from each common point/corner to the map edge (twice for each corner- one for x, one for y). Then pick two points and measure between them and compare your measurements in the "real world" to come up with a scale (this is why excel is handy). Then you just go back to your GIS software and move each of the corner points the specified "real world" distance!
This DOES take time but it is probably the most accurate method you'll find for older maps (or aerials).
If you simply pick one or two points and rubbersheet or affine, you'll often end up with frustratingly bad results for these. Those advanced methods require many, many links with a higher accuracy than you'll be able to achieve. My method also has the benefit of accounting for rotation/skewing/etc (not all the aerials/maps will be the exact same orientation, dimension, and scale... in fact, it's rare that two have even one or two of these elements relatively close).
Good luck!
I use the HP Scanjet 4600 see-thru scanner to copy parts of large maps. This is a very thin, lightweight scanner, with a clear top. The top comes off, so you can put the scanner up against a photo on the wall, or lay it flat on part of a large map. You can see through it to see what you're scanning. Move it to different parts of the large image, then stitch the individual images together with Gimp. This scanner seems to be discontinued, but perhaps you can borrow one or buy it used. Alternately, use a digital camera, but my experience is they seem to produce a lot of perspective problems and distortion around the edges. Doesn't stop me from using my camera, just know it won't be as perfect as a scanner.
Rather than bothering with PTgui or Hugin, why not just buy yourself a Gigapan robot?
http://www.gigapansystems.com/
A very good excuse, if you were ever looking for one. I can't help with the GIS angle of the problem, but the GRASS recommendations seem good.
I'm sure microsoft would come to the party...
My guess is since you posted this to Slashdot, you are looking for advice on how to do this yourself as a novice, instead of hiring the services of countless professionals willing to have you as their customer. I'm not a GIS expert, but I do work in aerial imagery, and have successfully done what you described.
It sounds like you have an old map, and assuming it is somewhat proportional in x and y directions, and would like for it to be georeferenced so that you can project shapefiles (of modern streets, property parcels, etc) over it. Or maybe you did not know that is a possibility. With this, you can also project modern imagery over it, and do side-by-side and wipe comparisons. This is cool stuff- I understand your enthusiasm!
If the map is monochrome- black and white with no grayscale- I'd aim for it to end up as a vector image, to make a shape file of. Whats nice about this is if there are details you might not want in your shapefiles, like rogue markings, irrelevant text or grids, etc, they can be edited out. If its grayscale or color, then I'd aim for keeping it as an image and retain as much of the original information as possible.
Some talk posted here about using a camera- even something about 'making' a x/y stepper motor thing- I personally would not consider anything other than a contact flat bed scanner. An inexpensive flatbed scanner with a removable lid works well when placed upside down over your map laying on a flat surface. Maintain an adequate degree of overlap, try to keep your scanner as square as possible (but you can fine tune the ortho rectification later) and work your way around in a grid patten. Make notes, save in uncompressed image formats at first, max your DPI scan rate and back up your original scans.
For my project, I had the good fortune of having grid lines on my original work which was very helpful in manually lining each scan relative to its neighbors. I used GIMP. There might even be software out there that will do the stitching for you.
Once you have your scans stitched together, you need to determine if it will be practical/possible to ortho rectify and georeference the map. You will need to be able to positively and precisely identify the lat/long of as many points on the map as possible. Road intersections are ideal.
If you can identify several points, you can load your image into a GIS application to produce a world file (wikipedia it) to accompany your digital map. Now it is georefrenced. However, GIS applications can be intimidating. The most well known commercial ones are simply not for the novice, but there are a few open source ones- try Map Window GIS, or just Google GIS open source.
Not sure what the chances of this are, but if your map is within your area, your local government (county level probably) GIS/environmental services department might be interested in assisting you, espeically if there is some value to them in having a digital copy of your map.
Good luck!
I would suggest a local university or museum first. If they won't help you for some reason (and I think they would be interested to say the least), shoot me an e-mail. I would take great pains not to damage your maps further and could give you good quality scans that are color correct and I'm also pretty good at repairing things if there is something to go buy. Solid color areas are not a problem to replace and fix, but anything with loads of detail starts getting into the "fake it till you make it" territory and is not reproduction anymore if you ask me. Any crinkles in the paper, etc can usually be effectively cloned out. I work for a small shop. Our prices on prints, etc are pretty reasonable. Scans are usually like $60 or so, but that includes a lot of time in color correction. Also what you are looking for is something that will likely take a bit of time and effort unless you have a big expensive scanner on hand. I deal with framed paintings a lot, and I can't just run a framed painting through a drum scanner or a wideformat. I usually have to either carefully lay it across a flatbed and scan a few sections or put it in the studio and shoot it, but that introduces all sorts of problems as others have said with lighting, lens distortion (no lens is perfect, especially near the corners), etc, which generally leads to somewhat of a loss in quality. Even with a medium format back you can get millions of pixels, but that image is still only as clear as the glass in front of it. A flatbed scanner is certainly ideal (unless you want to say lose the paper texture from the scan, then the camera is actually better) and will give you results with microscopic clarity. I mean hell even a cheap epson will do like 9600 dpi or so and to be honest, unless I'm scanning negatives, I rarely scan over 600dpi. If I were you I would by a cheap 11x17 scanner that does not have a recessed bed. Meaning that when you take the lid off, the scanning glass is flush with the sides of the plastic top. This is important as scanners have a fairly shallow depth of field. Now what you want to do is take your maps and get a big heavy piece of glass. Don't use plex or at least get a couple of pieces of plexiglass, as you will just basically scratch it to hell with the scanner and your efforts to clean it as it get dusty. Place the glass on a map. Next rip the lid off your scanner and start scanning away. Use the preview to judge your overlap between scans and try to give a good 10% overlap as this will help in the stitching process. You can probably get away with less, but I like to leave some room for human error as well. Make sure each scan has auto exposure and color turned off. Use a medium to high unsharp mask if you want more of the texture if your scanner software supports this. (You can also just sharpen a little in photoshop later if you like) Now scan your map in sections. Try to go for about 300 dpi if the maps are larger. If they are smaller (10x10 or so) you can bump up to 600dpi. Open up photoshop or something capable of doing rectilinear mapping and photostitch your scans. Photoshop CS4 does a wonderful job here, and if you use PS, I really recommend going ahead and using the ruler tool and rotate->arbitrary to straighten the edges of your scans as well as cropping out anything that isn't part of the image. This will make your stitching go much smoother and be less error prone as well as getting proper blends at the seams. You'll have to fix up the levels and color a bit since you turned off the autocorrection, but this should give you a good start if you really want to do it on your own. Hit up my e-mail if you would like to ask questions. I'd be happy to help as much as possible.
zosxavius photography
Where we work we have a number of maps, some older than 100 years and not in that great of shape. If they are in a frail condition we will put them in a protective sleeve before scanning in our large format scanner. Normally a large format scanner has rollers or something to pull the map through the scanner. The rollers could damage old frail maps. The sleeves we made are basically 2 large, thin (transparency thick), clear plastic sheets that are taped on three sides to make a pocket. Slide the old map into it and run it through the scanner. Scanners use light and there is the possibility of problems with reflections so you may have to play around with it some and find the right plastic sheets but it will work and it does a good job of protecting your maps.
I've used ESRI to digitize and geo-rectify paper maps, you could see what they offer. They have the big high-res scanner and experience that you need. Who knows, maybe they have a history buff on their staff that would do some pro-bono work. http://www.esri.com/
You should record the type of lens used, the type of camera... and set up a tripod over the map, keep it consistent, and take a few pictures of reference items.
Recording the lens type and all of the exact settings would make it easy to use software to correct for distortion. The reference... grid of say 1cm by 1cm squares with some other simple geometry to test your math.
Please use [ informative / summarizing ] SUBJECT LINES
Flame me here
http://slurl.com/secondlife/Rumsey%20Maps%201/133/247/56/?title=David%20Rumsey%20Maps&msg=David%20Rumsey%20map%20collection
See also http://www.davidrumsey.com/
There's no sense in being precise when you don't even know what you're talking about. -- John von Neumann
I have been doing this as part of my master's thesis, with scanned maps. Something like this solution using GIS is definitely the way to do it, however, I have a few things to add.
This is something that greatly benefits from a GUI approach. Command-line-style GIS can be powerful, but when you're matching up features like this, being able to just point and click on the two points you want to match is really a lot easier. I have played around with the open source GIS programs, but am not familiar enough with them to offer any specific advice. I have access to ArcGIS and use that for everything - I can say at least that in Arc, this stuff is really very simple point-and-click stuff, though very powerful with plenty of options too.
In any case, to get something to match your maps to in whatever GIS software is used, one can get high-resolution georeferenced topographic maps and aerial and satellite imagery from USGS and NASA, for free. Since the poster is apparently not in the US the US topographic maps probably aren't helpful, but LANDSAT satellite imagery, for example, is available for most of the earth and is usually pretty good (if not spectacularly high in resolution - it's 15m pixels at best).
There are a few commercial windows packages designed to do this. BlueMarble comes to mind, but it's pricey. Golden Software's "Didger", is probably the best bang for your pound: high mathematical accuracy and well supported by its manufacturer. It's really quirky, though. (Disclaimer: Five hours ago I relinquished my position as project manager for this program.)
I work for Spatial Data and Mapping and deal with geocoding scanned maps quite often. Some of these maps are scanned, others (I never saw the equipment) photographed by cameras in some kind of dedicated room. I am assuming that once the map is geocoded it will be released to be used by others? For such map to be useful you'll need to build a metadata record, with lineage not only for the historical map, but for the method of geocoding, including estimated accuracy. This is why outsourcing to 'anyone willing', unless well supervised, may not be the best option. I use ArcScan for my geocoding. I use whatever other digital data can find as my reference, topo maps, satellite imagery, aerial photography. I make notes for each map, writing down what references I used, how many points I had to create, what kind of errors they brought with each algorithm and I also save the point file. Be aware that old maps were not always drawn in proportion and geocoding may not always be possible. Projection, as someone mentioned, matters also, depending on the scale of the map. It also depends on the purpose of the map. For example, when I georeference old hand drawn land unit map I use, as my reference, satellite imagery and concentrate on matching landscape features. If man-made features (tracks, buildings) are coming out of kilter, I don't care. But I'd point that out in my metadata. So ask yourself - what is the purpose of this map, what is it going to be used for, and by whom. Good luck!
I've done work for some government departments who have to create digital archives of artworks and old manuscripts and they all use very high end digital cameras and a controlled lighting environment.
Iff (if and only if) you have an environment where the camera is in a fixed position, and you have lights of a known intensity in fixed positions, then you can do a proper calibration on the camera, generate an ICC profile, and then scan away knowing that you're capturing an accurate representation of the colours in the artworks.
These cameras are $50k units - medium format with high quality prime lenses and digital backs - this will give you an idea of what can be done:
PhaseOne and Hassleblad
Specialist Mac support for creative pros, Melbourne
maybe you can come up with an idea to combine an old plotter, a digital camera and free stitching software like hugin. .~.
You're talking different resolution metrics. Even high density film on a 35mm frame has a larger ERROR in grain location than a modern 10-12MPix DSLR image. Being irregular, however, the resolution of the 35mm film *seems* better because you can usefully oversample.
This doesn't really introduce more information and you're much better off double-printing (where every point on the map has an appearance on at least two images. Being much more regular, you can double or quadruple your resolution this way.
I have helped with similar tasks previously, where an Egyptologist had used a digital camera on a portable frame to take mosaic images of rock carvings.
http://tawbaware.com/forum2/viewtopic.php?t=1849&highlight=egypt+terje
Modern panorama software, both open source and very cheap commercial offerings, makes it possible to determine semi-automatically how multiple images are connected, while correcting for things like lens projection errors, camera location offsets and even some exposure correction.
In your case I would use a panorama head on a tripod, put the maps on top of a square grid, and then take sufficient number of images to get the final resolution you think you need.
The part of the grid that remains visible makes it easy to flatten the resulting mosaic.
I used PTAssembler on that Egyptian mosaic, highly recommended!
http://www.tawbaware.com/ptasmblr.htm
Terje
"almost all programming can be viewed as an exercise in caching"
There is a program that comes with FalconView called GeoRect. You open an image in the program then set the geographic positions of a few known points. From that, GeoRect can georectify the entire image so that you can display it in FalconView or other GIS tools. Search for GeoRect at http://www.falconview.org/
Ha, ha! Nobody ever says Italy.
Rent a Red Camera http://www.red.com/cameras/
If you got damp maps, put them in the freezer, in some sort of freezer proof bag. it will draw the water out.
Be seeing you...
You can also check out Blue Marble Geographics. They provide a suite of applications for performing coordinate conversion, raster transformation, etc. The Geographic Transformer application provides raster image georeferencing capabilities using MANY different coordinate systems, datums, etc.
You want to either buy, rent, or find a service provider that can do large-format scanning using Contex scanners or other large format scanner. These utilize multiple CCDs or CISs to enable single pass color capture of large blueprint or map size documents. These can be at native resolutions of 72, 100, 200 dpi or higher. Can't help you with the GIS, but if you want fast, quality digitization, stick with an actual scanner made to do the job.
I am kind of working in this field so forgive this shameless plug.
Look at http://help.oldmapsonline.org/. In this project we document and develop tools that can be used to put old maps online. One of them is our MapTiler (http://www.maptiler.org/). However, as you noted, if you want to create overlays your maps have to be georeferenced. There are two ways.
1) If your maps are not older than late 18th century and you know their projections and coordinate systems, providing coordinates of map corners is enough.
2) For older maps the usual method is by providing ground control points. Basically you mark the same locations on your map and some reference map. From this you can calculate distortion, affine transformation etc.
If you publish your maps as Zoomify (see the oldmapsonline.org site on how to do it), you can use our Georeferencer (http://www.georeferencer.org/) to do the ground control points georeferencing. Than you get KML for Google Earth and WMS which can be viewed in OpenLayers webviewer. Examples of both viewers are on the Georeferencer too. Or you can just download the worldfile that was generated and use it to crate GDAL VRT dataset or something.
https://ucgc.welborn.wmich.edu/
Lots of good stuff here.
I would recommend imaging twice. For the first one, Get a print of graph paper with a 1" grid done on mylar film. Put the film over the image.
This gives you a control grid that you can use to correct for distortion of your imaging system. In particular if you end up imaging in chunks, each chunk will have distortion to correct for.
In creating your transformation, you have two things to consider: One is the projection used. Others have mentioned this. While knowing it will make it simpler, it should be possible with 9-16 well spaced control points to determine it.
The other factor is errors made by the surveyors. This one is more subtle, as there will be a 'circle of influence' around landmarks. A landmark that is highly visible, and well located (church spire on hill) will have a strong influence. A pond will have a much smaller influence just because the surveyors couldn't see it.
Surveyor errors may be random or systematic. E.g. If they are using a magnetic compass a declination error will have the effect of adding a shear transform to the image. A time piece that gains or loses time can stretch or contract the path. If it was done by a team, some of the team may be more careful than others. You may find one class of detail accurate, and another class less accurate.
A third source of error is the modern map. Unless *really* new, many maps are not orthorectified properly. The compensation for the position of a landmark due to the oblique angle of the aerial photograph depends on the elevation. And that in turn depends on both the quality of the stereoscope, the skill of the operator, and the attention to detail in the whole imaging process.
Recently I used a GPS and a 30 year old Canadian Topo map to create a cross country orienteering game. In our region the river has cut a broad valley about 150 to 200 feet below the plain. The location of the rim, as indicated by the contour lines was consistently about 50-80 meters off. East west coordinates were up to 150 meters off.
Good luck on your project.
Third Career: Tree Farmer Second Career: Computer Geek First Career: Teacher, Outdoor Instructor, Photographer.
yea, what keosak said. avoid any advice that includes the term "geocoding" as that is not what is going on here at all. /* ROTFLO! */
Basically the scan can be accomplished entirely separately from the georeferencing process. You could even do that at, say, Kinko's or something and then bring the .tif into some GIS software and get busy doing what amounts to a pin, stretch, and refine process where your goal is to minimize the RMS for the most important areas or just overall.
Like this guy says, there are strong advantages to putting it in the JPG 2000 format. You might also consider porting it to the new GeoPDF thingy that USGS is now using as a method for topo distribution. If you really wanted to go out on a limb, you could reproduce them and embed anoto in the copies and do fun stuff in situ there. In any case, until you get them reasonably georeferenced, you won't need to worry about the original projections at all for any reason, period. That simply doesn't apply here for a number of reasons that include but are not limited to: a) scalar accuracy of the originals b) datum and/or projection of base reference c) allowable RMS error in an affine transformation will certainly allow for any wack in projection hocus-pocus. That said, it might be interesting to actually know it such that you could get a quantitative handle on the accuracy/ precision of the originals.
If you do get around to it, please let us know on SlashGeo as lots of us folks like old maps... ...geocoding.....lol
Good stitching software doesn't distort the image, it actually un-distorts the image. As long as the camera is parallel with the maps, the only distortion in the photographs is actually created by the lens in the act of taking the photograph, lens distortion aka barrel distortion. You have have a circular convex lens producing a rectangular picture. In order to do this, everything not at the center of focus is increasingly distorted as you move farther from that center of focus. Good stitching software actually undoes this distortion creating a linear image again before doing the stitching. So what you may deem as the software distorting the image, is actually the software correcting the image. Bang for buck, a high res camera taking as many photos as you can stand to take of a single map then stitching them, is the best way to go.
wow, that is like really getting down to brass tacks with the consideration of nadir convolution and so on. dude, you rock! hey, perhaps giving the ASPRS a ring and getting this done right is a good idea. It could be a nice vehicle for an article on process, eh ?
I would recommend that your first stop be with someone who preserves old photographs, paintings, and such. They can help you by stabilizing the paper the maps are printed on. Then they can also recommend putting them on a acid free linen or some such to strengthen them further thereby helping them to be preserved. Contact a museum to get names of people that are local to you who can do this. It won't be cheap but if these maps mean a great deal to you, you will find it worthwhile. If you don't plan on keeping or restoring the maps after you have them scanned, I would recommend either donating them to a museum, or if they are truly old (usually >150 years old) getting an estimated value on them and the thinking about selling them through an reputable auction house such as Southby's.
Nothing remains as constant as change.
I photocopied some old (1888) plat maps from my county recorder's office and scanned the copies using an HP all-in-one. Then I used Paint.Net to assemble the scans into digital versions of each plat map. Finally, I imported each digital plat map into Google earth as an image overlay and aligned the features on the map with terrain in Google Earth. So, for my local area, I can go to any place in Google Earth and, by turning on the overlay, see what was there 120 years ago. It's pretty cool.
http://www.cs.ubc.ca/~heidrich/Papers/EG.04.pdf
"Design of an Inexpensive Very High Resolution Scan Camera System".
500 megapixels for $1600 versus scanning-back cameras that cost tens of thousands. Make the error correction a little bit simpler by rotating the scanning back ninety degrees for four 4-color shots (16 exposures), overlaying them, and taking the median pixel values, at the expense of some resolution.
There are four considerable challenges here, though, not just one, and this project could stall on any of them:
Image capture
Projection determination & georeferencing
Digitizing features & establishing topology
Geocoding
People in Soviet Russia, however, appear to be afflicted with amusing juxtapositions of the aforementioned situation
I would highly recommend getting a hold of the AGS. They have an extensive collection of maps and are in the process of digitizing their own collection. I suspect that they would be willing to help you, or at least provide the necessary information to get you on the right track. If you happen to be within driving distance of Milwaukee, even better. Here's their contact information:
The AGS Library
University of Wisconsin-Milwaukee
P.O. Box 604
Milwaukee, WI 53201-0604
Tel: (414) 229-4785
http://www.amergeog.org/
Check out our work at the New York Public Library: http://maps.nypl.org - we've been working with some folks active in the OpenLayers community to get a set of web-based tools in place for georectification and shape tracing off of historic maps...
- Josh Greenberg, Director Digital Strategy/Scholarship, NYPL
I also work with scanning large old (and new) maps as a part of my job. If the maps can at all be handled you will save GREAT deals of time if you can beg, borrow, or lease a wide format scanner. As others have recommended, check with universities, museums, and local government agencies to see if you can get time with one. Setting up and photographing/scanning small portions of hundreds of maps is going to be a lot of work, never mind stitching all those pieces together.
We have a variety of 19th and early twentieth century hand-drawn maps on paper and linen; as another poster recommended, create a cover slip by purchasing a long piece of clear acetate (costs us around $45USD for a 1 x 2.5 meter sheet) and folding it in half. We don't find it necessary to tape edges. This will protect any frayed or torn edges, as well as providing some structural support and protection from the rollers. We use a CCD type wide format scanner and don't seem to have any problems with reflection from the acetate.
If the maps are too fragile for that process, or too large for available scanners, I think your best bet is to find a museum, art gallery, or other historical society with a good setup for photographic reproduction and beg their help. If they are that delicate I certainly would not ship them anywhere.
Good luck with georeferencing - I've only looked into this a little but for now I can't consider any non-automated solutions due to the sheer number of maps I have as well as my very finite budget.
Nice! When you are done with scanning and would like to publish them on a site and maybe overlay them on the openstreetmap or googlemaps let me know, I can help you with this. I work on daily basis with online maps so thats easy for me.
GeoRegArcView is a free utility which lets you make an ESRI world-file to georeference any jpg. You just have to identify the lat/lon of any 2 points on the map, and it can generate the file.
The world file is a text file the same name as the original file, with a "w" on the end of it (e.g. .jpgw). It identifies the upper left corner of the image and the degrees-per-pixel in the horizontal and vertical directions.
Even if your images won't be .jpg, you can convert to jpg just to generate the world file, and then rename the world file to .bmpw, .tifw, etc.
1. Contact the NOAA library staff at http://www.lib.noaa.gov/ for suggestions.
2. Contact National Archives staff for suggestions.
During the last International Conference of the History of Cartography there were one guy presenting a tool to do what you want, after you scanned them.
Read about there suggestions on : http://help.oldmapsonline.org/
You can also see my simplistic way to do the same with the prescanned maps from The Danish Roayl Library(https://images.kb.dk/kortbog?b=35&s=1), but only in dansih, at : kb.gmaplink.com/