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Adobe Photoshop Family

16 Messages

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282 Points

Thu, Mar 31, 2016 4:28 PM

Solved

Photoshop: Split channels on large CMYK files gives glitches when converted to bitmap or saved as tiff

This has happened to me on CS6 and now with CC on OSX running El Capitan. When I split channels on a large CMYK file the resulting files look fine, but when I convert them to bitmap or save them as a grayscale .tiff or .psd I wind up with glitched files. This does not happen if I cut and paste the channel into a new grayscale file, so I think it is a bug in the split channels code. Original CMYK file was 7393x5700 pixels

BITMAPPED WITH A HALFTONE SCREEN




SAVED AND REOPENED AS A GRAYSCALE TIFF


ORIGINAL IMAGE AFTER SPLITTING CHANNELS ( BLACK CHANNEL )

Responses

Official Solution

Adobe Administrator

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14.8K Messages

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284.8K Points

5 years ago

That was the secret. I have a repro case now. Engineering will look into it. Thanks for your help!

Sr. Product Manager, Adobe Digital Imaging

16 Messages

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282 Points

That's great! Also easy to work around now that I know.

Official Solution

Adobe Administrator

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14.8K Messages

 • 

284.8K Points

4 years ago

Sr. Product Manager, Adobe Digital Imaging

Adobe Administrator

 • 

14.8K Messages

 • 

284.8K Points

5 years ago

Does this happen consistently (100% of the time) with all files or this particular file?

Sr. Product Manager, Adobe Digital Imaging

Adobe Administrator

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14.8K Messages

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284.8K Points

5 years ago

I wasn't able to reproduce this creating my own CMYK file, splitting the channels and saving a tiff of each file using the default settings in the Tiff options dialog,

Sr. Product Manager, Adobe Digital Imaging

16 Messages

 • 

282 Points

5 years ago

It only happens if the CMYK file is not flattened and split channels creates a transparency channel. I can create a new file the same size and there is no problem. Double click the background layer to make it Layer0, and the glitch manifests. I flattened the original file and now there is no glitch.

Adobe Administrator

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14.8K Messages

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284.8K Points

OK. The sounds like it might be the secret sauce. Let me try that.

Sr. Product Manager, Adobe Digital Imaging

15.1K Messages

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195.8K Points

Ah, yeah, that is something that wasn't mentioned in previous reports.
And that tells me where the error might be...

16 Messages

 • 

282 Points

5 years ago

I can also send you the file I used if you can't replicate the bug, but I was able to get it to happen with a file I created in photoshop.

15.1K Messages

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195.8K Points

5 years ago

Yep, those steps (transparency, large image) were both important.
I've implemented a fix for this in the next major release of Photoshop.