xnviewmp 1.5.3 bug: artifacts when viewing with hq algorithms

[xmozg]

xnviewMP 1.5 64 bit win10 latest updates.

The appearance of image artifacts when reducing the image in view mode when using high-quality algorithms (except for billinear and none).

Problem reproduction:
1. set any high-quality algorithms in the options (from bicubic to lanczos4)
2. look at the images when they are reduced by a certain percentage. For example for 1080p (scale will be different for different resolutions
) image starting from 57% or less for lanczos4, 42% for lanczos3 and spline 36, 28% for spline 16 and bicubic.

Problem encountered: The image is darkened, showing horizontal shading stripes across the entire image, and a gray stripe at the bottom of the image.

Expected result: the image is displayed without all these stripes and retains visual content regardless of the scale.

Original 1080p image downloaded from here: https://www.pixelstalk.net/wp-content/u ... wnload.jpg

Normal:

Artifacts with lanczos4 at 54%:

[xnview]

i'm not able to reproduce. Do you use windows font scaling? could you post a screenshot of Settings>View?

[xmozg]

I am not using any windows scaling.

[xnview]

i can't reproduce. You have this grey line each time, for each image?

[xmozg]

Line appearance depends only on the zoom algorithm and the zoom level itself. Clearer looking algorithm (toward lanczos 4) - earlier line appears when zooming out. A less sharp looking algorithm (spline 16 and bicubic) means that the image can be scaled down further until a line appears. Therefore, with the lanczos 4 algorithm, I see a line in most of the pictures.

[xmozg]

I tried using the portable version with the default settings, changing only the "high zoom quality zoom out" setting. The problem hasn't changed. It's not about the settings.

[xnview]

I tried using the portable version with the default settings, changing only the "high zoom quality zoom out" setting. The problem hasn't changed. It's not about the settings.

Could you try to disable Settings>General>Icc? I've tried on another computer, but no problem, with same image & zoom level/algorithm

[xmozg]

I've tried turning this setting off, it doesn't help. Maybe indeed windows is stealthily interfering with the xnview? I have any processing and text scaling disabled in windows.

[xnview]

I've tried turning this setting off, it doesn't help. Maybe indeed windows is stealthily interfering with the xnview? I have any processing and text scaling disabled in windows.

and no problem with 1.4.5?

[xmozg]

The bug occurs only on high quality zoom algorithms (bicubic or better), in version xnviewmp 1.4.5 it is impossible to enable high quality zoom out algorithms (bug 2790, fixed in 1.5.0), so there is no bug in it.
In version 0.98.2 it was possible to enable high quality zoom out algorithms (bicubic or better) and they worked without this bug with a gray line and without darkening of the picture. I don't know if this information is important.

[xnview]

i send you a PM

[Klaus1189]

Same as viewtopic.php?f=82&t=45754

I am not alone, but Dev takes care of it

[xnview]

Thanks to your detailed description I can reproduce the problem.

[xnview]

This problem is supposed to be fixed in XnView MP 1.5.4. Please check and confirm the bug fix here.

[xmozg]

Bug is fixed