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Author Topic: Looking for a good Test image  (Read 3252 times)

sloow

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Looking for a good Test image
« on: August 18, 2007, 06:29:03 pm »

Hi,

Just wondering if someone could point me to a good test image or set of test images to print on different papers for comparison and evaluation purposes for different papers and profile settings. I'm using a Z3100, I don't see that HP supplies one in looking around their web site.

Thanks,

Paul
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Avalan

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sloow

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Looking for a good Test image
« Reply #2 on: August 19, 2007, 12:16:03 am »

Hey thanks,

that's just what I was looking for!

Paul
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Chris_T

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Looking for a good Test image
« Reply #3 on: August 19, 2007, 08:03:53 am »

Two great articles. Is there another one that talks about how to print the test image?

Quote
Paul

Check these  links  :

http://www.outbackprint.com/printinginsigh...i048/essay.html

http://www.outbackprint.com/printinginsigh...i049/essay.html
[a href=\"index.php?act=findpost&pid=134045\"][{POST_SNAPBACK}][/a]
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madmanchan

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Looking for a good Test image
« Reply #4 on: August 19, 2007, 11:00:38 am »

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Two great articles. Is there another one that talks about how to print the test image?
[{POST_SNAPBACK}][/a]

The idea is to print the test image using the profile for the paper you're printing on. This could be a manufacturer-supplied profile, or a custom profile. You can use whichever Rendering Intent you want, though typically it will be Perceptual or Relative Colorimetric. The idea is to look at the results and see how well the profile performs.

See here for a discussion of how Jack Flesher suggests using the test image:

[a href=\"http://www.outbackprint.com/printinginsights/pi049/essay.html]http://www.outbackprint.com/printinginsigh...i049/essay.html[/url]

Remember, this is primarily a test of how the profile performs. Separate, different tests should be performed if one wants to test a basic driver setup (e.g., correct driver settings).
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Eric Chan

Avalan

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Looking for a good Test image
« Reply #5 on: August 19, 2007, 01:29:42 pm »

Chris

Eric is correct . Few notes to the how to print question:

Do not change anything in the file (size , color , etc) . print the file as is using the proper profile you may have for the combination of the paper/ink .

The file is pro photo RGB. If you are using PS and and a setting other than prophoto RGB, it might be a good idea to set your PS settings to pro photo RGB before openning the file.

Regards - Avalan
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Chris_T

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Looking for a good Test image
« Reply #6 on: August 20, 2007, 10:39:05 am »

Eric and Avalan, thanks for the responses. I should clarify my question.

There are plenty of test images out there, but few of their creators offer help on how they should be printed and how the prints should be evaluated. What makes the two Outback articles terrific is that the test target incorporates several popular images and Jack took the trouble to detail what and how to evaluate the prints. It would even be better if he could be more precise on how to print the target.

For instance, I recall a custom profile vendor suggesting to print a target *without* using profiles, just to test the intrinsic capability of covering color and tonal gamut by a printer and a particular set of media, i.e. paper and ink. Can the Outback target be used for this purpose, and how?

Then printing the target with profiles using the conventional way (openning target in PS with a certain color space, Soft Proofing with profile and No Color Management at printer, etc.) would make much more sense. The evaluation would then allow an user to see the impact of the profiles and rendering intents.

In the Outback target, there are seveal gray scale and color patches. According to the following PhotoDisc evaluation, not all these are created equally. An user needs to know which ones to use for evaluation.

http://home.att.net/~arwomack01/#pdievaluate

I only wish that things are simpler.
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madmanchan

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Looking for a good Test image
« Reply #7 on: August 20, 2007, 01:56:12 pm »

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It would even be better if he could be more precise on how to print the target.

As stated previously, the target should be printed using the exact same printer and color management (i.e., profile) setup that you plan to use for printing normal images (i.e., your own images).

Two examples:

1. Suppose you plan to print on an Epson 3800 on Epson Premium Luster paper using the Epson-supplied profile (Pro38 PLPP). You open the Outback Photo test images in PS and print using a color-managed workflow, such as the one suggested here:

http://people.csail.mit.edu/ericchan/dp/Ep...flow.html#color

Perhaps you make two sets of test prints, one using Perceptual and one using Relative Colorimetric. You make sure to choose the correct driver settings (e.g., Media Type = Premium Luster Photo Paper, 2880 dpi, etc.). You print, you let the prints dry (e.g., overnight), and then you evaluate and compare using -- for instance -- the criteria that Jack described in his article.

That's all there is to it.

2. Suppose you've gotten a custom profile made for your printer and you want to see how good it is, say, compared to the stock/canned profiles. You do the same process as described above, except that instead of using the stock profile you use your custom profile. Again, you make the print, let it try, and compare side by side. This should make improvements and deficiencies clear.

Quote
For instance, I recall a custom profile vendor suggesting to print a target *without* using profiles, just to test the intrinsic capability of covering color and tonal gamut by a printer and a particular set of media, i.e. paper and ink. Can the Outback target be used for this purpose, and how?

No. As stated previously, the Outback images are designed to evaluate profiles, not the raw state of a printer. While you certainly can print the Outback images with color management completely turned off, it's not particularly meaningful. You're better off in this case using the Atkinson Profile Test Images here:

http://homepage.mac.com/billatkinson/FileSharing2.html

and using the Hues, Blends, Twenty-Eight Balls, etc. images for testing a driver setup. One can also print a profile target to get an idea of the expected gamut for a driver setup.

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In the Outback target, there are seveal gray scale and color patches. According to the following PhotoDisc evaluation, not all these are created equally. An user needs to know which ones to use for evaluation.

Sure, but for evaluation purposes it doesn't really matter how they're created. You have a reference -- how the patches appear on your color-managed display. You also know the exact RGB values -- e.g., by using the color picker in Photoshop. Now you have a test print made, and you can compare to the soft proof on your display how the results look. If the hues of the patches are way off, there's a problem. If the grays look distinct on your display but can't easily be differentiated in the print, there's a problem. If the grays have a green/magenta tint, there's a problem.

Again, many of these potential issues are already spelled out in Jack's essay ... just print and compare ...
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Eric Chan
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