1.8.0: (JPEGLI) XYB cororspace images created by XnView MP using JPEGLI encoding are very blurry.

[lffs]

XYB cororspace images created by XnView MP using JPEGLI encoding are very blurry.
See the screenshot, below.
On the left is the original image.
In the middle is the image created by XnView MP (check Convert to XYB colorspace in Options).
On the right is the image created by cjpegli.exe, a command line tool provided by libjxl.

It can be seen that the quality of the image created by XnView MP is not good.

Windows 11 23H2 x64
XnView MP 1.8.0 64-bit

A sample image will be attached below:

sample.zip

(77.85 KiB) Downloaded 145 times

[Kadet]

You set in XnView coding 2x2, 1x1, 1x1.
Look on file size and info about file.

[lffs]

You set in XnView coding 2x2, 1x1, 1x1.
Look on file size and info about file.

I'm not sure if this is the key to the problem as cjpegli.exe also saves Subsampling as 2x2,1x1,1x1.
I set the quality to 90%, but the quality of the output image is still poor, as you can see from the screenshot of the file size, or by downloading the sample image.
The file size saved by Xnview MP is 15KB, the file size saved by cjpegli.exe is about 33KB, and the original image is about 40KB.

[Kadet]

You have right. When in XnView is set 2x2 where is some bug. But 1x1 give the same image as in cjpegli.

[xnview]

Thanks to your detailed description I can reproduce the problem.

4:2:0 is inversed with 4:2:2

[WinnieW]

Color subsampling is for YUV colorspace in JPEG only, XYB colorspace should be used without any subsampling.

[xnview]

This problem is supposed to be fixed in XnView MP 1.8.1. Please check and confirm the bug fix here.

[lffs]

This problem is supposed to be fixed in XnView MP 1.8.1. Please check and confirm the bug fix here.

fix confirmed. thank you.

[Kadet]

This problem is supposed to be fixed in XnView MP 1.8.1. Please check and confirm the bug fix here.

No, problem still is. Settings 422 and 420 give the worst compression against to cjpegli.

And 422 give 420 in output file, and 420 make 422 jpeg file.

Source file:

seria2.png (26.84 KiB) Viewed 2878 times

Edit: I set quality on 91.

[xnview]

No, problem still is. Settings 422 and 420 give the worst compression against to cjpegli.

I have the same as cjpegli, it seems that you dont use --xyb

[Kadet]

No, problem still is. Settings 422 and 420 give the worst compression against to cjpegli.

I have the same as cjpegli, it seems that you dont use --xyb

It doesn't make a difference if I used or not xyb in XnView — yesterday.
But today you are right, there is a quality difference whether I set xyb in XnView, I forgot to set xyb in cjpegli and now I have basically similar results (the difference of a few bytes is due to the newer version of cjpegli).
Sorry, I may have mixed something up yesterday.