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Better Test Pages for Color Printers?
AigariusDebian asks: "I bought a new color laser printer (Lexmark C510), but I am not sure if my driver configuration gets all the best images out of it. I would also like to have some way to brag about it to other laser printer wielding geeks. That means that I'd need to make some kind of repeatable and measurable testing of the printers quality. Are there any good Postscript test files that will allow a non-expert to do a full test of their color laser printer? I am thinking about both resolution, dithering and color matching testing."
The page tests all of the colours, as well as a resolution test by drawing lines in a circle 1 degree apart. A standard on most *nix machines, the CUPS page should be well recognized and serve as a good benchmark.
mattdev@server$ touch
cannot touch `/dev/genitals': Permission denied
I wrote this one: ColorCard.pdf (1.4Mb).
It tests all the characteristics of a printer that I cared about:
Of course, you'll need a reference card by Kodak, etc. to test against, but I've found this is the simplest way short of developing a whole complex spot color sample group of colors closer to the edges of gamut.
There is no need to use a SlashDot sig for SEO...
Here is a test image that I believe was designed for printer/monitor color calibration (I dredged it up from the data recovered from a hard drive failure a while back). It is 2297x3600x24 at a resolution of 360 pixels per inch for a final image size of 6.381x10 inches. Included on the image are several Kodak color charts, along with a variety of household objects and several faces of varying skin colors.
Here is another test photo of the same style as the first one. According to the CNET Labs printer page, this is "the industry-accepted PhotoDisc Target document." Not sure about that (especially with the website logo in the corner of the image), but whatever. It works nonetheless.
Following with the previous recommendation of finding a vibrant nature photo, I located a rather beautiful photograph (free registration required for download) of the Grand Canyon with a large variety of colors at 1200x1600x24.
I have been thinking about this on and off for a while now (still stuck in lowly inkjet-land). Thanks for finally motivating me to do some research. Hope this aids you in your obsessive-compulsive quest to achieve satisfaction from knowing every little defect in your printer.
For many years, Photographers have used test shots of women, they nicknamed her Shirley for no reason I've ever been able to figure out. Oftentimes the woman is a pale redhead, as those particular skin and hair tones are hard to render in print, but easy to see if they are not rendered correctly. Skin tones tend to be pale and even a slight miscalibration will cause dramatic color shifts. After working in prepress a few years, I found that I can tell if a color separation is OK just by looking at the individual C M Y and K negatives, if I look at skin tones in a face.
In that regard, one of my favorite test images is "Ole No Moire" that used to come in versions of Photoshop (I don't think it comes in current versions, I haven't seen it in years). Ole no Moire also has step wedges on the image. The one thing it won't do is test out the fancier PostScript features, it's just a bitmap image. I like to create my own step wedge charts in Adobe Illustrator, so I can test exactly the features I want to see.
There are other sorts of high-tech test images, like the IT8 test pattern. Of course, a printout of this is absolutely unintelligible except to a colorimeter, but if you have a full color calibration system, these are essential. A more general color guide used by photographers is the MacBeth ColorChart, which is a set of 24 basic colors and greys, they're all chosen carefully so that if the color balance is wrong, at least one color will stand out as mismatched when you compare it to the original chart.