Image Processor (CS5) greyscale images convert to Dot Gain 20% not sRGB

[piotrm59209442]

I have some image files that are greyscale (have no visible color, clearly are black and white), but have RGB Color + 8bits/Channel mode and they already have the sRGB profile.
Because I convert various different image files in the same run, in the Image Processor I always check "Convert Profile to sRGB" and "Include ICC Profile" to make sure that in the end every image is converted to sRGB and has the ICC profile.

The problem is that when those greyscale images with RGB Color, 8bits/Channel and sRGB profile go through the Image Processor, the resulting files have Greyscale mode and Dot Gain 20% color profile, instead of sRGB!

When I open them in Photoshop afterwards I get this error: "The embedded ICC profile cannot be used because the ICC profile is invalid. Ignoring the profile".

And in Bridge CS5 content window they show with no thumbnails.

I have to manually fix those converted files by changing their mode to RGB Color and assigning an sRGB profile to get their thumbnails to show in Bridge.

Is this a bug?

I tried changing the color settings in Photoshop for the Gray Working Space from Dot Gain 20% to sRGB, but sRGB is not listed in the drop down menu...

[D Fosse]

There's nothing that could normally explain this. What it sounds like, is that PS somehow assigns the dot gain profile to an RGB, three-channel image, which of course will return an "invalid" message, because it is. Normally, such an operation is not possible.

So it sounds like a corrupt preferences file, which can cause all kinds of erratic behavior. Under Edit > Preferences > General, press "reset preferences on quit". This returns Photoshop to its out-of-the-box factory state.

Save out !!! any custom actions, brushes and so on first. They are stored in the prefs file and will get deleted.

[piotrm59209442 · Accepted solution]

Thank you D Fosse for answering!

However, I have managed to pinpoint the issue, and it is not in Photoshop, as in turns out. I would upload the photos in question to a website and later download them, and the downloaded copies would be the ones saved with a Dot Gain 20% profile and in Greyscale mode, not the ones converted by the Image Processor. As it turns out, it is the CMS handling the conversion of the photos after uploading that causes the problem, for some reason it makes those black-and-white photos get a Dot Gain 20% profile and Greyscale mode. Opening them in Photoshop and changing the color mode to RGB automatically brings their sRGB profile back. The issue is in the CMS, luckily!