Image colors changing after saving

[AlbertoMaciel]

Hello!
I rendered a project and I noticed that after saving the image from the frame buffer, the image colors/contrast is changing a little bit
not sure if it's noticiable on the screenshot but here it is.
doesn't matter the format I save neither the software I open, the colors is actually being saved differently. This might be related to the daily build or I'm messing something up?

[romullus]

I'm quite sure this has nothing to do with daily builds, nor with Corona, or even 3ds Max. Most likely this is because your colour profiles is not set correctly in Windows. There's quite a few similar discussions about that in "I Need Help" section of the forum and most of them have solution to the issue. Try to do a search and see if you manage to fix the issue on your own.

Moving the topic to appropriate board.

[AlbertoMaciel]

I did read them all.
Most of the "fixes" were pretty much "Live with it, VFB displays different colors, you should fix on Photoshop" or something like that.
If the color profile is "wrong", it shouldn't display wrongly for everything that's on the screen? Or the color profile act different from software to software? Like, Photoshop, Image viewer, Pureref, EVERYTHING but VFB displays the image equally. VFB displays the image differently from everything else.

[Avi]

Hi,

I understand that you are having some problems with differences in colors after saving your rendered Image from the VFB in Corona. This could be due to a few factors. I will suggest some possible solutions:

1. Make sure that your color management settings are consistent across all software you're using. In 3ds Max, you can access these settings by going to Customize > Preferences > Gamma and LUT tab. Ensure that the "Enable Gamma/LUT Correction" checkbox is selected and that the Input and Output Gamma values are consistent (typically 2.2 for sRGB).

2. Different software may interpret color information differently, so ensure that you're using color-managed software for image viewing and editing. For example, use Adobe Photoshop or a similar application with color management capabilities.
"Color management is quite simple, and relies on two things:

– The image must have an embedded profile (known as the document profile),
    typically sRGB or Adobe RGB.

– The monitor profile must be correct and sound.

 When you open an image in a color-managed application, the colors are converted from the document profile to the monitor profile, which ensures that the correct colors are displayed.

Applications without color management (like Windows Photos) do not do this conversion"

3. I see that you are saving in the .tif format. When saving, see if you are not using any compression for it or you can also use .EXR or .HDR. These formats preserve more color information and can help reduce differences in color.

4. It's possible that your monitor's color profile is affecting the appearance of your images. Check your monitor's calibration settings and ensure that it's set to a standard profile, such as sRGB or Adobe RGB.
https://answers.microsoft.com/en-us/windows/forum/all/why-is-my-photo-viewer-off-color/183f74cd-0db8-48fa-8dc3-5373d3c58596

I hope this helps.

[Juraj]

I did read them all.
Most of the "fixes" were pretty much "Live with it, VFB displays different colors, you should fix on Photoshop" or something like that.
If the color profile is "wrong", it shouldn't display wrongly for everything that's on the screen? Or the color profile act different from software to software? Like, Photoshop, Image viewer, Pureref, EVERYTHING but VFB displays the image equally. VFB displays the image differently from everything else.

The threads do have answers and workaround solutions :- ). It's because there is no Color Profile in VFB, 3dsMax, or Corona, unless you're using 3dsMax 2024 which now supports color management.
Almost everything else does have color management, so it will be quite literally be only the VFB which is wrong.

The simplest solution is to install NoVideo sRGB clamp. 1-click solution. https://github.com/ledoge/novideo_srgb

[Juraj]

3. I see that you are saving in the .tif format. When saving, see if you are not using any compression for it or you can also use .EXR or .HDR. These formats preserve more color information and can help reduce differences in color.

This is misleading answer. File Formats are unrelated to Color Profiles (outside of supporting or not supporting them) and do not in any way reduce any perceived color difference, in fact they are capable of opposite since HDR file formats require wide-gamut colors to cover properly the extended dynamic range.

Not that it matters, 3dsMax/Corona outside of 2024 version do not embed any color profile information at all anyway. Jpegs or EXRs, 3dsMax/Corona outside of 2024 provide zero color management. File Format should be chosen depending on intended post-production workflow, SDR (Jpeg/Tiff/PNG/etc..) or HDR (.Exr, .Hdr).

Edit: I have yet to test 2024 Max, to see if Corona respects the new color management (and if it respects the current Windows .icc profile). I hope it does.

[Avi]

3. I see that you are saving in the .tif format. When saving, see if you are not using any compression for it or you can also use .EXR or .HDR. These formats preserve more color information and can help reduce differences in color.

This is misleading answer. File Formats are unrelated to Color Profiles (outside of supporting or not supporting them) and do not in any way reduce any perceived color difference, in fact they are capable of opposite since HDR file formats require wide-gamut colors to cover properly the extended dynamic range.

Not that it matters, 3dsMax/Corona outside of 2024 version do not embed any color profile information at all anyway. Jpegs or EXRs, 3dsMax/Corona outside of 2024 provide zero color management. File Format should be chosen depending on intended post-production workflow, SDR (Jpeg/Tiff/PNG/etc..) or HDR (.Exr, .Hdr).

Edit: I have yet to test 2024 Max, to see if Corona respects the new color management (and if it respects the current Windows .icc profile). I hope it does.

Sorry if this was not clear but I was referring to these file formats specifying how image data is stored i.e. some formats(Exr and Hdr) can store more color and luminance info than others. I hope you were not using some kind of compression at the time of saving the .tif file format. The color profiles however is a separate thing from file formats.

[Juraj]

It still doesn't matter how much volume a file format contains when it doesn't come with profile to specify how they are meant to be interpreted.
File format will not make any change between how colors look in non-managed application (Corona VFB) and managed application (Photoshop) because the issue is in application, not the file itself. They will still look different. 3dsMax and Corona will always look wrong unless they are overridden by application such as NoVideo_sRGB or color management is "cancelled" (Windows has generic color profile (such as "sRGB IEC 61966.icc") and monitor has internal 3D LUT file that corresponds to the space).

Or, if 2024 really solved everything finally :- ).

TIFF compression also shouldn't affect colors unless 3dsMax has some kind of bug. It's loss-less compression, visually identical.

[Avi]

I know it shouldn't, but who knows, unless we figure out how the Images were saved. ;) It's just one of many factors I mentioned that could have contributed to the user's issue. I believe this thread covers all potential solutions to the problem the user is facing.

[maru]

@AlbertoMaciel - can you please explain how exactly you are saving your images (what format and settings in 3ds Max) and how exactly you are opening them?
If you could share a simple scene where the issue is reproducible, that would be great (even just a single teapot).
I am asking for this, because if we are able to reproduce it, then we may be able to:
- at least understand and explain what exactly is going on in your case
- fix something if it's wrong in Corona
- try Max 2024 + new versions of Corona to check if the issue still occurs there
Feel free to continue here or submit a support ticket at https://support.chaos.com/hc/en-us/requests/new 

[AlbertoMaciel]

Hi,

I understand that you are having some problems with differences in colors after saving your rendered Image from the VFB in Corona. This could be due to a few factors. I will suggest some possible solutions:

I hope this helps.

Thanks for your answer. Somehow, I missed it cause I didn't get a notification about a reply.
My monitor is color-corrected using Spyder5 Elite. The weird thing is that every other software (color corrected or not), displays the image the exact same way. VFB is the only different  one lol
I wish I could just update to max 2024 and get everything color correct but 3ds max developers are so lazy that community have to rely on plugins for everything and wait for them to be updated...

[AlbertoMaciel]

I did read them all.
Most of the "fixes" were pretty much "Live with it, VFB displays different colors, you should fix on Photoshop" or something like that.
If the color profile is "wrong", it shouldn't display wrongly for everything that's on the screen? Or the color profile act different from software to software? Like, Photoshop, Image viewer, Pureref, EVERYTHING but VFB displays the image equally. VFB displays the image differently from everything else.

The threads do have answers and workaround solutions :- ). It's because there is no Color Profile in VFB, 3dsMax, or Corona, unless you're using 3dsMax 2024 which now supports color management.
Almost everything else does have color management, so it will be quite literally be only the VFB which is wrong.

The simplest solution is to install NoVideo sRGB clamp. 1-click solution. https://github.com/ledoge/novideo_srgb

I don't think I've ever heard about this. That's very interesting. I'm checking it out right now. Thank you!

[Juraj]

One word of warning, the way it integrates into Windows, it means on laptops that are running Optimus (Switching between Intel & nVidia graphics) it won't work properly, depending on how the display is connected to GPUs.
On neither of my laptops the tool work until I switch off Optimus to exclusive dedicated GPU (nVidia).

No such problem on desktop of course.

[AlbertoMaciel]

@AlbertoMaciel - can you please explain how exactly you are saving your images (what format and settings in 3ds Max) and how exactly you are opening them?
If you could share a simple scene where the issue is reproducible, that would be great (even just a single teapot).
I am asking for this, because if we are able to reproduce it, then we may be able to:
- at least understand and explain what exactly is going on in your case
- fix something if it's wrong in Corona
- try Max 2024 + new versions of Corona to check if the issue still occurs there
Feel free to continue here or submit a support ticket at https://support.chaos.com/hc/en-us/requests/new

I can share this project with you guys. The displacement maps are huge but they don't make any different to reproduce my problem. The colors are still the same.
I won't upgrade to to 2024 for a while because you know.. plugins, etc.
I'll upload the file as soon as possible