For most of the time between '94 and now, I haven't been able to leave the US without jeopardizing my ability to return. As for returning, I'm stuck between a rock and a hard place. If I do leave after getting my Ph.D., I'm draining the US's intellectual resources, if I stay, I'm a hippocrit. I'd like a third option please:-) Just out of curiousity, are you yourself South African linving in South Africa? Or offering your expert commentary from a safe distance much as you accuse me of doing?
My personal reaction is that the notion of civil union is distinctly insulting, it reeks of an attempt to appease homosexuals while maintaining a "seperate but equal" policy. If the purpose of marriage is solely to produce children, then why are childless heterosexual couples still allowed to be married? And what about those heterosexual couples who aren't able to conceive? I think it would only be fair in those cases to nullify those marriages and replace them with civil unions. But that's just me. If you're curious about what gay, lesbian, bisexual, & transgendered people expect from marriage, PFLAG has some information. The Human Rights Campaign also has more information.
It's not just tax benefits. With marriage comes something like 2743 rights in the state of Virginia (your mileage will vary state to state) including shared insurance benefits, hospital visitation rights (which is a big one), power of attourney rights, etc. Quite frankly, the tax benefit doesn't make such a huge difference when you've got another mouth (or two or three) to feed.
Please explain the link between violent crime rates and the progressiveness of legislation, because it's not apparent in your argument. You seem to assume some a priori connection between legislation and its enforcement which I'm afraid doesn't exist. There are many states in the US which have bizarre laws still on the books, like requiring that there be a place to hitch your horse outside every residence, which are not enforced.
(Note: this isn't a flame or a troll, just the obersvations of a South African living in the US)
It appears that, in general, South Africa has leapt way ahead of the US in a large number of policy areas, not just Open Source. They've got fundamental protections in their constitutions which are significantly stronger than those in the US (for example, you can't discriminate based on percieved sexuality, domestic partnerships are law, with same sex marriages in the works, etc.) Now, to be fair, I haven't been back in SA since the '94 elections, so I don't know how much of the new government's legislation has made it into actual practice, but it does seem odd that SA is apparently overtaking the US in terms of the general "cluefulness" of the administration.
i'm working on a real time computer vision system. capture runs in its own thread, firing off imageArrived events which end up being executed in the capture thread (a subtlety of qt that i was unaware of). this imageArrived event gets plugged into whichever listeners are interested, the idea being to allow multiple paths of processing the same image. i attempted to do this using timers, having capture events posted peridiodically and then occasionally refreshing. this was very unsatisfactory for two reasons: 1) it looks awefully slow even though i know that it's running very quickly underneath and 2) (more importantly) this method will only ever use a single processor. as i expand to do more interesting processing, i'm going to be forced to use multithreading because a single processor will not be able to do it all in the allotted amount of time, however, multiple processors could because of how much of these processes are easily parallelizable. for a rough guestimate of how much processing is involved, there are four classifiers per pixel (three based on chrominance or one based on luminance and two based chrominance plus a classifier that combines the output of the three other classifiers), 640x480 pixels 30 frames per second for a grand total of 37 odd million classifications per second. add to this the possibility of yuv to rgb conversion, and contraction/expansion filtering to clean up noise and you can quickly see how the time adds up. this is before i even begin to do anything useful with the images --- this is just removing the boring pixels. so far, this is all integer arithmetic on arrays that are "cache friendly" in their layout. the really cpu intensive stuff comes later (this is all preprocessing in terms of my application)... updating classifier's background models, extending classification to foreground, background, and things that have been merged into the background (i.e. have stayed still long enough, either items removed from the scene, added to the scene or moved within the scene).
for those who were wondering, i did figure it out with a number of critical sections synchronized indirectly on xlib's mutex. performance is actually better threaded than with earlier single threaded prototypes (mostly because i am now able to start processing an image while i start getting the next one). looking back, i realize that most of my frustration is the result of the vast majority of my gui programming experience being done on windows in applications that were fundamentally stupid to thread. as the message that cliff pointed out notes, this particular quirk of x is not very well documented and has the potential to be very counter intuitive to people doing this for the first time.
anyways, thanks a lot for the help. for those who are curious, my goal is to release the source for the framework and sample application within a month.
she was also a rear admiral in the navy, coined the term, "debug" and had trouble balancing her check book because she thought in octal rather than decimal. there's also the fact that she was the first woman to recieve a ph.d. in mathematics from yale. more info here. definately a cool chick;-) byte magazine did a really nice bio on here in their 25th anniversary edition too.
a complete list of interesting candidates can be found here.
alan definately has my vote, of course, i'm slightly biased in this, given that he's the father of my field (ai). unfortunately, 90+% of people don't know turing's full story --- a lot of people are surprised to find out that he started at bletchley park cracking enigma and ended up committing suicide thinking he was snow white (eating a poisoned apple). it was turing's stored program concept that was the foundation for the von neumann architecture, so in a sense turing is the father of computing in general. anyways, for more info, try here or here
i (like the poster, i think) want this all in one place. like i said, most of the pieces are out there, but there's no glue yet. more to the point, i'm lazy --- i don't want to spend any more time thinking about how to make this work than trying to remember what the command to start the executable is. much more effort and it's time that should be spent on research wasted.
You're describing something that I have wanted to build ever since my advisor started handing me papers to read left, right and center. Unfortunately (or not, depending on how you look at it), I haven't had enough time to do more than think, "wow, what I really want is a database that can hold these papers, do some kind of semi-intelligent indexing, keep notes, and figure out what the BibTeX entry should be."
From the little bit of research that I've done, a lot of the pieces for this are already out there (i.e. APIs for manipulating PDFs, database engines, indexing engines, etc.) but I just haven't had the time to put any of it together. Anyways, if anyone does have an answer please let me know about it;-)
And enjoyed playing it for over 3.5 years now.
I think the clue is there. As games go, it's ancient and certainly not where Sony is putting it's focus in terms of gaming --- I am willing to wager that Sony's new PC and PS2 titles are making them significantly more money than EQ is. Think about it: given finite resources, how would you assign them? To the cash cows? Or a sack of bones with teets that drag across the floor because they've been milked too hard?
you have a better solution? or justification as to why that code is so bad? wait, what was i thinking this is/. silly me, expecting some soft of constructive criticism.
Re:kinda neat, butt...
on
Robocoaster
·
· Score: 1
hrm... i always wanted to hack a roller coaster *evil grin*
My specific issue has to do with code that looks like this:
class C { public:
C(const string& s = "some string"); };
icc wants code that looks like this:
class C { public:
C(const string& s = string("some string")); };
The only real difference I see between the two is the explicit creation of a temporary. Now, as to why GCC doesn't complain is another issue --- maybe its diagnostics for temporaries aren't turned on with -Wall (perhaps -pedantic fixes that); however, I have this feeling that GCC's constructor elision is the trick here. To be honest, I'm very curious to find out why this happens. As an interesting aside, Stroustrup tackles the issue of overloading operators in a "smart" way so as to avoid unecessary copies.
Personally, I think Java (and whomever it "borrowed" these particular semantics from) got it right. Unfortunately, Java isn't exactly a good language for talking to hardware;-)
i've been using icc on a realtime computer vision project that i'm working on. intel's compiler ended up giving me an approximately 30% boost over all --- a difference which is not to be sneezed at. in terms of empirical performance data for my application, icc wins hands down.
that said, icc does a lot of things that really irritate me. for one, it's diagnostic messages with -Wall are, well, 90% crap. note to intel: i don't care about temporaries being used when initializing std::strings from constants --- the compiler should be smart enough to do constructor eliding and quit bothering me. the command line arguments are somewhat cryptic, as are the error messages you get when you don't get the command line just right. the inter procedural optimization is very *very* nice; however, be prepared for *huge* temporary files if you're doing ipo across files (4+mb for a 20k source file adds up very quickly).
this all said, i don't think that i'm going to give up either compiler. gcc tends to be faster on the builds (especially with optimization turned on) and has diagnostics that are more meaningful to me. fortunately, my makefiles know how to deal with both;-)
is what this sounds like. i have java code that does it, if you're interested. turning the java into somethime like a screen saver is an exercise for the reader;-)
The solution to this problem should be fairly easy (this doesn't mean non-trivial) to implement, assuming that a couple conditions hold:
The border around every image shows a high contrast against the scanner background (which is usually white). This shouldn't be too much of a problem, unless you take lots of pictures of very light things.
Your photographs are rectangular. This may sound silly, but it's a lot easier to find a rectangle than some arbitrary n-gon.
Your photographs are placed so that edges of the photograph run parallel to the bed (i.e. you put the pictures down squarely)
If (1), (2) and (3) hold, then implementing this shouldn't be too bad --- I would use this algorithm:
take a scan of the background of the scanner (i.e. hit the scan button with no pictures on the bed) and remember this background image
for each image in the input set
perform edge detection
use a Hough transform to detect lines in the edge map
calculate the difference image D. If B[k](i,j) is the value of the k color band at pixel (i,j) in the background image and F[k](i,j) is the value of the k color band at pixel (i,j), then D(i,j) = max(abs(F[r](i,j)-B[r](i,j)),abs(F[g](i,j)-B[g](i, j)),abs(F[b](i,j)-B[b](i,j))
divide the difference image and the input image into rectangular regions using the lines that were detected with the Hough transform. For each region, calculate the average difference; if this value is large enough (i.e. over ~ 8-16), then consider that region to be a picture, otherwise it's blank space.
Intel's OpenCV library (look it up at SourceForge) can do most of the "tough" stuff for you (i.e. the edge detection and the Hough Transform). Hope this helps:-)
ACM Technews (for those of us who get it) also has an article about this here. Hrm... Wonders idly whether that spinning noise is Einstein in his grave...
FWIW, this table may provide some incentive to complete your degree. Note the median $13k per year premium for a bachelor's degree v. high school and additional $8k per year premium for a master's degree. Doing a little arithmetic, the average median income for people in the IT industry according to the US Bureau of Labor Statistics is around $55,505; quite how the premiums for higher education are affected by this is hard to tell, I can't seem to find statistics for middle 50% salaray by industry and education. But hopefully this will give you some incentive...
... which is something I guess many people can't say. Of course, I'll eventually grow out of the student phase, but I'm hoping that I'll have my tenure by then;-)
Urm, dunno 'bout you, but I sure as hell don't want the people that I'm competing *against* in terms of the grading curve to have anything to do with how my work gets graded. Even if there isn't a curve --- are you sure that having people who may not like you or necessarily have a good enough grasp of the material moderating your posts? Personally, I don't think the web can replace a real instructor --- I *need* face time; however the web (when done properly) make for a nice supplement.
Assuming that n is an integer, rather than a random variable with mean x and standard deviation sigma.... I'm curious --- can you copyright a random variable?
I hate to say it, but not everyone has the sort of mind that is well suited to CS, and it's not the sort of discipline that will let effort replace genuine smarts and understanding. I've been a tutor for CompSci 3 at my university for a number of semesters and the major problems I see are: a) people not having a clue how to use the environtment (which, in our case is csh + gcc on a DEC VAX/Tru64 cluster), b) people who don't have sufficient discipline to be effective, c) too many people who are in CS for the money. a) is fairly easy to correct --- I have a set of tutorials that I've put together on getting an editor up, basic commands, subduing g++ and make, etc. b) is harder --- CS3 is usually where the wunderkinds come to realize that they too are mortal, some of them wake up after the first project and end up doing well, many end up failing because they aren't willing to put in the time. c) heh... good luck, my experience with many of the people that fall into this group is that they switch to MIS (which is an option at GMU). There are a lot of people for whom CS is too counter-intuitive for them to ever really develop their understanding beyond a certain depth. Such is life -- not everyone has the sort of mind that predisposes them to be a good musician or physicist, there's no point in getting bent out of shape over it. The people who should be in CS will survive, regardless. The rest will eventually make their way out. Let the intro sequence decide who sinks and who swims.
I think your effort would be best spent on putting together a set of workshops or brief online tutorials showing how to use the environment. Then suggest that they read Code Complete and Programming Pearls:-)
Slashdot Mirror
I disgust you because my family left the country when I was 13 (i.e. before I had any say in the matter)?
For most of the time between '94 and now, I haven't been able to leave the US without jeopardizing my ability to return. As for returning, I'm stuck between a rock and a hard place. If I do leave after getting my Ph.D., I'm draining the US's intellectual resources, if I stay, I'm a hippocrit. I'd like a third option please :-) Just out of curiousity, are you yourself South African linving in South Africa? Or offering your expert commentary from a safe distance much as you accuse me of doing?
My personal reaction is that the notion of civil union is distinctly insulting, it reeks of an attempt to appease homosexuals while maintaining a "seperate but equal" policy. If the purpose of marriage is solely to produce children, then why are childless heterosexual couples still allowed to be married? And what about those heterosexual couples who aren't able to conceive? I think it would only be fair in those cases to nullify those marriages and replace them with civil unions. But that's just me. If you're curious about what gay, lesbian, bisexual, & transgendered people expect from marriage, PFLAG has some information. The Human Rights Campaign also has more information.
It's not just tax benefits. With marriage comes something like 2743 rights in the state of Virginia (your mileage will vary state to state) including shared insurance benefits, hospital visitation rights (which is a big one), power of attourney rights, etc. Quite frankly, the tax benefit doesn't make such a huge difference when you've got another mouth (or two or three) to feed.
Please explain the link between violent crime rates and the progressiveness of legislation, because it's not apparent in your argument. You seem to assume some a priori connection between legislation and its enforcement which I'm afraid doesn't exist. There are many states in the US which have bizarre laws still on the books, like requiring that there be a place to hitch your horse outside every residence, which are not enforced.
(Note: this isn't a flame or a troll, just the obersvations of a South African living in the US)
It appears that, in general, South Africa has leapt way ahead of the US in a large number of policy areas, not just Open Source. They've got fundamental protections in their constitutions which are significantly stronger than those in the US (for example, you can't discriminate based on percieved sexuality, domestic partnerships are law, with same sex marriages in the works, etc.) Now, to be fair, I haven't been back in SA since the '94 elections, so I don't know how much of the new government's legislation has made it into actual practice, but it does seem odd that SA is apparently overtaking the US in terms of the general "cluefulness" of the administration.
i'm working on a real time computer vision system. capture runs in its own thread, firing off imageArrived events which end up being executed in the capture thread (a subtlety of qt that i was unaware of). this imageArrived event gets plugged into whichever listeners are interested, the idea being to allow multiple paths of processing the same image. i attempted to do this using timers, having capture events posted peridiodically and then occasionally refreshing. this was very unsatisfactory for two reasons: 1) it looks awefully slow even though i know that it's running very quickly underneath and 2) (more importantly) this method will only ever use a single processor. as i expand to do more interesting processing, i'm going to be forced to use multithreading because a single processor will not be able to do it all in the allotted amount of time, however, multiple processors could because of how much of these processes are easily parallelizable. for a rough guestimate of how much processing is involved, there are four classifiers per pixel (three based on chrominance or one based on luminance and two based chrominance plus a classifier that combines the output of the three other classifiers), 640x480 pixels 30 frames per second for a grand total of 37 odd million classifications per second. add to this the possibility of yuv to rgb conversion, and contraction/expansion filtering to clean up noise and you can quickly see how the time adds up. this is before i even begin to do anything useful with the images --- this is just removing the boring pixels. so far, this is all integer arithmetic on arrays that are "cache friendly" in their layout. the really cpu intensive stuff comes later (this is all preprocessing in terms of my application)... updating classifier's background models, extending classification to foreground, background, and things that have been merged into the background (i.e. have stayed still long enough, either items removed from the scene, added to the scene or moved within the scene).
for those who were wondering, i did figure it out with a number of critical sections synchronized indirectly on xlib's mutex. performance is actually better threaded than with earlier single threaded prototypes (mostly because i am now able to start processing an image while i start getting the next one). looking back, i realize that most of my frustration is the result of the vast majority of my gui programming experience being done on windows in applications that were fundamentally stupid to thread. as the message that cliff pointed out notes, this particular quirk of x is not very well documented and has the potential to be very counter intuitive to people doing this for the first time.
anyways, thanks a lot for the help. for those who are curious, my goal is to release the source for the framework and sample application within a month.
she was also a rear admiral in the navy, coined the term, "debug" and had trouble balancing her check book because she thought in octal rather than decimal. there's also the fact that she was the first woman to recieve a ph.d. in mathematics from yale. more info here. definately a cool chick ;-) byte magazine did a really nice bio on here in their 25th anniversary edition too.
a complete list of interesting candidates can be found here. alan definately has my vote, of course, i'm slightly biased in this, given that he's the father of my field (ai). unfortunately, 90+% of people don't know turing's full story --- a lot of people are surprised to find out that he started at bletchley park cracking enigma and ended up committing suicide thinking he was snow white (eating a poisoned apple). it was turing's stored program concept that was the foundation for the von neumann architecture, so in a sense turing is the father of computing in general. anyways, for more info, try here or here
i (like the poster, i think) want this all in one place. like i said, most of the pieces are out there, but there's no glue yet. more to the point, i'm lazy --- i don't want to spend any more time thinking about how to make this work than trying to remember what the command to start the executable is. much more effort and it's time that should be spent on research wasted.
You're describing something that I have wanted to build ever since my advisor started handing me papers to read left, right and center. Unfortunately (or not, depending on how you look at it), I haven't had enough time to do more than think, "wow, what I really want is a database that can hold these papers, do some kind of semi-intelligent indexing, keep notes, and figure out what the BibTeX entry should be."
From the little bit of research that I've done, a lot of the pieces for this are already out there (i.e. APIs for manipulating PDFs, database engines, indexing engines, etc.) but I just haven't had the time to put any of it together. Anyways, if anyone does have an answer please let me know about it ;-)
And enjoyed playing it for over 3.5 years now. I think the clue is there. As games go, it's ancient and certainly not where Sony is putting it's focus in terms of gaming --- I am willing to wager that Sony's new PC and PS2 titles are making them significantly more money than EQ is. Think about it: given finite resources, how would you assign them? To the cash cows? Or a sack of bones with teets that drag across the floor because they've been milked too hard?
you have a better solution? or justification as to why that code is so bad? wait, what was i thinking this is /. silly me, expecting some soft of constructive criticism.
hrm... i always wanted to hack a roller coaster *evil grin*
My specific issue has to do with code that looks like this:
;-)
class C {
public:
C(const string& s = "some string");
};
icc wants code that looks like this:
class C {
public:
C(const string& s = string("some string"));
};
The only real difference I see between the two is the explicit creation of a temporary. Now, as to why GCC doesn't complain is another issue --- maybe its diagnostics for temporaries aren't turned on with -Wall (perhaps -pedantic fixes that); however, I have this feeling that GCC's constructor elision is the trick here. To be honest, I'm very curious to find out why this happens. As an interesting aside, Stroustrup tackles the issue of overloading operators in a "smart" way so as to avoid unecessary copies.
Personally, I think Java (and whomever it "borrowed" these particular semantics from) got it right. Unfortunately, Java isn't exactly a good language for talking to hardware
i've been using icc on a realtime computer vision project that i'm working on. intel's compiler ended up giving me an approximately 30% boost over all --- a difference which is not to be sneezed at. in terms of empirical performance data for my application, icc wins hands down.
;-)
that said, icc does a lot of things that really irritate me. for one, it's diagnostic messages with -Wall are, well, 90% crap. note to intel: i don't care about temporaries being used when initializing std::strings from constants --- the compiler should be smart enough to do constructor eliding and quit bothering me. the command line arguments are somewhat cryptic, as are the error messages you get when you don't get the command line just right. the inter procedural optimization is very *very* nice; however, be prepared for *huge* temporary files if you're doing ipo across files (4+mb for a 20k source file adds up very quickly).
this all said, i don't think that i'm going to give up either compiler. gcc tends to be faster on the builds (especially with optimization turned on) and has diagnostics that are more meaningful to me. fortunately, my makefiles know how to deal with both
is what this sounds like. i have java code that does it, if you're interested. turning the java into somethime like a screen saver is an exercise for the reader ;-)
http://dvbackup.sourceforge.net/ FWIW, http://www.schirmacher.de/cgi-bin/dclinks.cgi?acti on=view_category&category=Linux+Software has whole bunch of DV software. While you're at it, you may want to check out Kino which appears to work great. For more fun software to use with your DV cam, check out Arne Schirmacher's pages. Good luck ;-)
- The border around every image shows a high contrast against the scanner background (which is usually white). This shouldn't be too much of a problem, unless you take lots of pictures of very light things.
- Your photographs are rectangular. This may sound silly, but it's a lot easier to find a rectangle than some arbitrary n-gon.
- Your photographs are placed so that edges of the photograph run parallel to the bed (i.e. you put the pictures down squarely)
If (1), (2) and (3) hold, then implementing this shouldn't be too bad --- I would use this algorithm:- take a scan of the background of the scanner (i.e. hit the scan button with no pictures on the bed) and remember this background image
- for each image in the input set
- perform edge detection
- use a Hough transform to detect lines in the edge map
- calculate the difference image D. If B[k](i,j) is the value of the k color band at pixel (i,j) in the background image and F[k](i,j) is the value of the k color band at pixel (i,j), then D(i,j) = max(abs(F[r](i,j)-B[r](i,j)),abs(F[g](i,j)-B[g](i
, j)),abs(F[b](i,j)-B[b](i,j))
- divide the difference image and the input image into rectangular regions using the lines that were detected with the Hough transform. For each region, calculate the average difference; if this value is large enough (i.e. over ~ 8-16), then consider that region to be a picture, otherwise it's blank space.
Intel's OpenCV library (look it up at SourceForge) can do most of the "tough" stuff for you (i.e. the edge detection and the Hough Transform). Hope this helpsACM Technews (for those of us who get it) also has an article about this here. Hrm... Wonders idly whether that spinning noise is Einstein in his grave...
FWIW, this table may provide some incentive to complete your degree. Note the median $13k per year premium for a bachelor's degree v. high school and additional $8k per year premium for a master's degree. Doing a little arithmetic, the average median income for people in the IT industry according to the US Bureau of Labor Statistics is around $55,505; quite how the premiums for higher education are affected by this is hard to tell, I can't seem to find statistics for middle 50% salaray by industry and education. But hopefully this will give you some incentive...
... which is something I guess many people can't say. Of course, I'll eventually grow out of the student phase, but I'm hoping that I'll have my tenure by then ;-)
Urm, dunno 'bout you, but I sure as hell don't want the people that I'm competing *against* in terms of the grading curve to have anything to do with how my work gets graded. Even if there isn't a curve --- are you sure that having people who may not like you or necessarily have a good enough grasp of the material moderating your posts? Personally, I don't think the web can replace a real instructor --- I *need* face time; however the web (when done properly) make for a nice supplement.
Assuming that n is an integer, rather than a random variable with mean x and standard deviation sigma.... I'm curious --- can you copyright a random variable?
I hate to say it, but not everyone has the sort of mind that is well suited to CS, and it's not the sort of discipline that will let effort replace genuine smarts and understanding. I've been a tutor for CompSci 3 at my university for a number of semesters and the major problems I see are: a) people not having a clue how to use the environtment (which, in our case is csh + gcc on a DEC VAX/Tru64 cluster), b) people who don't have sufficient discipline to be effective, c) too many people who are in CS for the money. a) is fairly easy to correct --- I have a set of tutorials that I've put together on getting an editor up, basic commands, subduing g++ and make, etc. b) is harder --- CS3 is usually where the wunderkinds come to realize that they too are mortal, some of them wake up after the first project and end up doing well, many end up failing because they aren't willing to put in the time. c) heh... good luck, my experience with many of the people that fall into this group is that they switch to MIS (which is an option at GMU). There are a lot of people for whom CS is too counter-intuitive for them to ever really develop their understanding beyond a certain depth. Such is life -- not everyone has the sort of mind that predisposes them to be a good musician or physicist, there's no point in getting bent out of shape over it. The people who should be in CS will survive, regardless. The rest will eventually make their way out. Let the intro sequence decide who sinks and who swims. I think your effort would be best spent on putting together a set of workshops or brief online tutorials showing how to use the environment. Then suggest that they read Code Complete and Programming Pearls :-)