VLC 2.0.1: Weird color deviations in snapshots

[vieekk]

I've been noticing some weird color deviations when creating snapshots from a video. When I play the video the colors are fine, but when saved to PNG. Well, see for yourself:



The upper one is the snapshot, the lower one is print-screened. Look at the bathroom wall for example, there are "purplish" colors which I cannot see while playing. I've tested with the newest version and one 1.x I had lying around. My OS is Windows 7 x64. It's a x264 encoded video, but I think I have noticed similar deviations for XviD and MPEG2 too. I use Direct3D as my output module, but have tried others too.

Any idea?

Edit: The print-screen screenshot has been resized from 1080p to 720p, since 1080p is my screen solution.

[jagabo]

Adjust your graphic's cards video proc amp. Use a levels test pattern.
https://forum.videohelp.com/threads/326496-file-in-Virtualdub-has-strange-colors-when-o...=1#post2022085

[vieekk]

Adjust your graphic's cards video proc amp. Use a levels test pattern.
https://forum.videohelp.com/threads/326496-file-in-Virtualdub-has-strange-colors-when-o...=1#post2022085

Thank you for your reply, but would this really be the solution? Note that I cannot see these strange colors while playing videos on my computer monitor or TV, they only appear in the screenshots/snapshots.

[jagabo]

The lower picture has the wrong levels. That's why it looks dull and washed out compared to the upper picture. The purplish spots are part of the picture -- what's really in the video. The lower picture has them too, it's just that the incorrect levels make them less obvious.

You may also have a rec.601 vs rec.709 color conversion problem. That causes slightly different colors.

[vieekk]

The lower picture has the wrong levels. That's why it looks dull and washed out compared to the upper picture. The purplish spots are part of the picture -- what's really in the video. The lower picture has them too, it's just that the incorrect levels make them less obvious.

Are you certain? Look at this snapshot from VLC and another video:



Is that what the video really looks like? Is x264 that bad with colors? It looks like a GIF image, that is compressed with very large quantization.

Edit: Looking at the snapshots now I cannot see the artefact while using Google Chrome, maybe the default Windows image viewer cannot read PNG's properly. This was strange.

[vieekk]

The lower picture has the wrong levels. That's why it looks dull and washed out compared to the upper picture. The purplish spots are part of the picture -- what's really in the video. The lower picture has them too, it's just that the incorrect levels make them less obvious.

You may also have a rec.601 vs rec.709 color conversion problem. That causes slightly different colors.

Okay, so I have solved it now! You could never see the problem as it was Windows Photo Viewer, Adobe Photoshop and Mozilla Firefox who used a faulty color profile (came with the monitor's drivers I guess) when displaying PNG. Posting here in Google Chrome made me see my error. Thank you. I will have a look at the washed-out colors too.

[jagabo]

I was going to say your new image looks fine to me. It's a little noisy but I suspect that's the camera's fault. And it could use a little more contrast. But otherwise the colors looked ok. Glad you got the problem sorted.

[vieekk]

I was going to say your new image looks fine to me. It's a little noisy but I suspect that's the camera's fault. And it could use a little more contrast. But otherwise the colors looked ok. Glad you got the problem sorted.

Haha. I posted at the VLC forums too and they also advised me to check out the washed-out colors problem (which I haven't noticed that much, but I will probably check it out). I got a little fed up when you were missing the obvious too (the snapshot looked horrible to me). Lucky me that I switched browser from Firefox to Chrome a couple of days ago and could see my error.

[jagabo]

By the way, your pictures look fine in Windows Photo Viewer here. Windows 7 64 bit.

[vieekk]

By the way, your pictures look fine in Windows Photo Viewer here. Windows 7 64 bit.

Yes, and they should. The problem was that the default Windows color profile (you can find it via right click on desktop) had been replaced by BenQ's color profile. So when installing the drivers for my BenQ monitor the BenQ profile became default. Having removed this color profile I think I should have the same setup as you, and therefor Windows Photo Viewer (and other applications using this color profile, such as Firefox) displays PNG fine.