Phatoshop 5.0 "include transfer function" option problem

[burya]

Thank to all for help with my previous problem.
On this occasion my problem more applicative than postscript.

I have client's Monotone EPS file built in Photoshop 5.0 and saved with "include transfer function" option on. After RIP image will be printed as negative. If I would save this file without "include transfer function" result will be positive (means all to spot mode). Considerable difference between 2 these files is in DeviceN LUT (means /PhotoshopDuotoneList [...] 255 <>): in first case it <FF..00>; in second opposite <00..FF>. Binary data are same.

It means that my application works according to file's data,
but I cannot to return to client because a cannot explain what is happened.

My problem: I cannot to simulate this situation on other files. It means I can simulate RIP result of original file, but I cannot build any file with similiar behavior, using "include transfer function" option will add to file the transfer function description code but not change DeviceN LUT.

I have not Photoshop 5.0, I've tried to use 5.5 and later versions.

My question is how to simulate similiar behavior?
Thank you in advance

Michael

 

[tgreer]

I admit I don't understand your question, but will attempt an explanation. Transfer functions are used to adjust output levels to a specific device. Make reds "more" red, grays "less" gray, etc.

I have no idea why any application that produces an EPS would have any reason to produce a transfer function, but many do.

(I say this because an EPS is supposed to be a placeable image, and as such should not include any device-specific code, including transfer functions.)

DeviceN is a colorspace. Transfer functions are applied after the device has done any color conversions.

Special effects, such as reversing colors (making negatives) can be achieved by writing a transfer function that inverts the number: {1 exch sub} on a monochrome device.

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Thomas D. Greer

http://www.tgreer.com

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