Differences in color between video and saved image from video?

[DavidS]

I have a video that I'm editing for YouTube and the color in the video looks a little off. However, when I do a screengrab from the video or save an image from the video using VirtualDub or AviDemux, the colors look perfect when viewing the still image.

I want the colors in the video itself to match the colors I get from a screengrab of the video.

Why are the colors in the saved image from the video being interpreted differently than the way the video players play the video and what changes should I make to the video to make the colors match up?

I hope the way I phrased this makes sense. I can post some samples if needed to better understand the situation.

Thanks

[DavidS]

Let me add some images to demonstrate this. This first one is a screen grab from my YouTube video using Microsoft Edge. The colors don't look like the way my video plays on YouTube but I like these colors better. These colors are similar to saving an image from my video using VirtualDub or AviDemux.


[Attachment 68882 - Click to enlarge]

This second one is a screen grab from my YouTube video using Firefox. These colors look very similar to the way my video plays on YouTube, but I like these colors less.


[Attachment 68884 - Click to enlarge]

So, in essence doing a screen grab from Microsoft Edge and from Firefox on my YouTube video yield entirely different colors. I want to tweak my video so it plays on YouTube with similar colors to my screen grab from Microsoft Edge.

I hope this makes sense. Truth be told, it doesn't make much sense to me, but these are just my observations.

Thanks

[poisondeathray]

The difference between those 2 screenshots in terms of colors (not the lower frame shading) is basically a Rec 601 vs. 709 difference

By convention, SD video uses Rec601 matrix to convert YUV to RGB. HD video uses Rec709. The method of converting YUV to RGB for display can result in different colors if there is a mismatch

In terms of colors, vdub will always use 601 for the preview and for taking screenshots by default, so it's usually correct for "SD", but incorrect for "HD". If vdub looks "correct", then that implies your video had the wrong colors to begin with

Local configuration can alter how video is displayed in terms of GPU acceleration (HW on vs. off) , drivers, even in terms the same browser on 2 different computers so I'm making some assumptions in terms of the info provided, but the vdub reference is a very consistent one

The way you appear to have it setup on your computer if Edge has similar colors as vdub - YT in Edge is using Rec601 to display the video (technically wrong colors for HD) , but YT in Firefox is using 709 (technically correct colors for HD, but you don't want that)

To do this color shift you would use a colormatrix filter to shift 601 to 709 in YUV, and flag it as 709 - so that most players will display the "wrong" colors on purpose (edge and vdub would now display differently to what you don't want). You could use avisynth, or vapoursynth, or ffmpeg . I do not think filter is available in vdub or avidemux

Assuming "worse colors.png" used Rec709 for the screenshot, it would look something like this in avisynth

#source filter
colormatrix(mode="rec.601->rec.709", clamp=0)

EDIT: actually in vdub2, video=>decode format has color space options Rec601 and Rec709 . vdub (classic) does not have that option

[DavidS]

The difference between those 2 screenshots in terms of colors (not the lower frame shading) is basically a Rec 601 vs. 709 difference

By convention, SD video uses Rec601 matrix to convert YUV to RGB. HD video uses Rec709. The method of converting YUV to RGB for display can result in different colors if there is a mismatch

In terms of colors, vdub will always use 601 for the preview and for taking screenshots by default, so it's usually correct for "SD", but incorrect for "HD". If vdub looks "correct", then that implies your video had the wrong colors to begin with

Local configuration can alter how video is displayed in terms of GPU acceleration (HW on vs. off) , drivers, even in terms the same browser on 2 different computers so I'm making some assumptions in terms of the info provided, but the vdub reference is a very consistent one

The way you appear to have it setup on your computer if Edge has similar colors as vdub - YT in Edge is using Rec601 to display the video (technically wrong colors for HD) , but YT in Firefox is using 709 (technically correct colors for HD, but you don't want that)

To do this color shift you would use a colormatrix filter to shift 601 to 709 in YUV, and flag it as 709 - so that most players will display the "wrong" colors on purpose (edge and vdub would now display differently to what you don't want). You could use avisynth, or vapoursynth, or ffmpeg . I do not think filter is available in vdub or avidemux

Assuming "worse colors.png" used Rec709 for the screenshot, it would look something like this in avisynth

#source filter
colormatrix(mode="rec.601->rec.709", clamp=0)

EDIT: actually in vdub2, video=>decode format has color space options Rec601 and Rec709 . vdub (classic) does not have that option

It looks like my video is Rec 709 but, by happenstance, I just prefer the colors when decoded using Rec 601. I want to keep my video Rec 709 but emulate the colors that VD displays when decoding using Rec 601.

I'm wondering if there's some simple conversion for my video rather than meticulously tinkering with the colors to try to achieve the same look.

In other words I want to keep my video Rec 709 and decoded using Rec 709, but have YouTube display it with similar or identical colors to the way VD displays it when decoding it using Rec 601.

Thanks