XnView Software

XnView MP 1.4.0 64bits
Windows 64bit (22H2), display resolution 3840x2160, win scaling 150%

Viewer
'High zoom quality' + 'Change color depth' few issues that affect only zoomed image, not file itself.

To reproduce:
1. run clean portable XnViewMP
2. open any image AND zoom-out to any value above 100%, e.g. to 200%
3. goto Settings -> View -> View tab
- change 'High zoom quality' to 'Zoom-out & Zoom-in' OR just 'Zoom-out' as there is no isse with 'Zoom-in'
- change filter to anything except default 'Bilinear', e.g. to 'Bicubic' 4. Press OK to save settings
5. open 'Change color depth' dialog AND tick 'Apply to image' checkbox

Issue A
6. change color depth to Greyscale 32.
image will become dark. The problem has the strongest effect at 4, decreasing to 256.
Issue B
6. change color depth to Colors 8
image will shift 1pixel to the top-left corner. Untick/tick 'Apply to image' checkbox to see effect


Related issue:

• 1.0: Checking or unchecking "Use alpha channel" "Show alpha" has no effect when using "High zoom quality"

Thanks to your detailed description I can reproduce the problem.

This problem is supposed to be fixed in XnView MP 1.5.0 beta. Please check and confirm the bug fix here.

1.5.0b1
A, B fixed

however,
Issue C1
1. set Zoom-in and Zoom-out to Bicubic in Settings
("High Zoom quality" sets on automtically in Viewer's View menu)
2. open test image

3. zoom to 200%
4. goto "Change color depth"
- tick "Apply to image" to see effect
5. set to Greyscale from 4 to 256
image will zoom-in within same canvas size


Issue C2
1. set Zoom-in and Zoom-out to Bicubic in Settings
("High Zoom quality" sets on automtically in Viewer's View menu)

2. close xnview and open this ^ image
it will be shown cutted from bottom-right at default 100%



it will be shown correctly if:
- press * OR
- switch off "High Zoom quality" in Viewer's View menu (unfortuntely this settin always reverts after restard)

user0 wrote: Sat Jun 17, 2023 5:52 pm image will zoom-in within same canvas size

how that???

it will be shown cutted from bottom-right at default 100%

yes another user had this issue. Issue doens't seems to be here when 'Zoom HDPI' is checked

xnview wrote: Mon Jun 19, 2023 2:59 pm

user0 wrote: Sat Jun 17, 2023 5:52 pm image will zoom-in within same canvas size

how that???

variant B

ok so the new issue with 'Zoom on HiDPI' off

all fixed in 1.5.0b2