Re: Table cloths phantogram (from "Need some help")


JackDesBwa|3D
 

I do not have much practice with it, but as far as I know, the good way to deal with printed colors is to work with ICC profile of the printer/driver/ink/medium combo, to simulate the limitations of the gamut and correct accordingly before the print (provided that you have a qualified screen with preferably a larger gamut). Unfortunately, a lot of printers do not measure/provide this profile.

You could try with a generic profile and hope that the non linearity is similar (this might be better than nothing, highlighting probable ghosting zones), but it will probably also depend on how the color are processed in the factory. Comparing with the result of your printer might help to find problematic areas too.
Another possibility is to print a file with specific color samples (with the final printer) and create the profile yourself (with a spectrophotometer or via a lab which will do it for you [in which case the image to print is prepared by them])

I think that the magenta-green anaglyph will not be better, because I guess that these colors will suffer similarly to the red-cyan ones.
If you want to try other anaglyph formulas, here are all the matrices used in Stereopix to produce the different variants of anaglyphs:
https://github.com/JackDesBwa/threejs-StereoscopicEffects/blob/master/src/StereoscopicEffects.js#L197-L268
For each pixel, the resulting RGB color pixel vector is {matrix left} × {color as RGB vector in the left image} + {matrix right} × {color as RGB vector in the right image}

Here how you can use the Gimp to preview how it will look like. In the View>Color Management menu, you can select the ICC profile file with "Soft-Proofing Profile..." entry:
softproof.jpg

In the navigation window (bottom right) you can see the original anaglyph (with way too much saturated colors [due to extreme contrast] to be printed correctly ; there is no ghost on my qualified screen here)
In the main window (center, partly hidden by the menu) you can see the way it will be printed (with a specific printer/driver/ink/paper)... with very visible double image.

A quick (and dirty) way is to reduce the contrast globally:
curve.jpg
softproof_lowcontrast.jpg
but people who do anaglyph have more subtle tricks to reduce the ghosting. :-)

Anyway, my point was show how color proofing could help, before actual print.

JackDesBwa

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