1.8.0 - viewer - High zoom quality - few issues

[user0]

XnViewMP 1.8.0 64bit
Windows11 (23H2), display resolution 3840x2160, win scaling 150%

Viewer - zoom - High zoom quality
few issues

To reproduce:
0. clean portable version and win DPI scale >100%, eg 150%
1. have test image in folder

test_img.png (563 Bytes) Viewed 2844 times

2. (optional) assign shortcut to 'High zoom quality' for easier reach, eg B


Issue A
3. open image at 100% in Viewer
4. press B (and hold)
image will shift a bit, it looks like a filter is applied
occurs when any option other than None is selected for the Zoom Out (Settings>View)


Issue B
3. goto Settings
- change Zoom Out to None (View > High zoom quality)
- press OK
4. close app
5. open image via double click in win file explorer
6. make selection
7. press B and hover cursor over image
'Show color information' will be enabled
selection rotation controls will be available (at the selection corners)
8. click on View menu
sometimes 'Info' will appear
repeat 4-8 steps ~10 times to reveal all issues




Related

• issues
  1.8.0 - viewer - High zoom quality - few issues (current post)
  - fixed -
  1.5.0 - viewer - High zoom quality - None still affects image (1.7.0)
  1.4.0 - viewer - High zoom quality + Change color depth issue (1.5.0)
  1.4.4 - viewer - High zoom quality - state out of sync (1.4.5)

[xnview]

Issue A
3. open image at 100% in Viewer
4. press B (and hold)
image will shift a bit, it looks like a filter is applied
occurs when any option other than None is selected for the Zoom Out (Settings>View)

yes, if you use win DPI > 150%, image at 100% will be scaled. Only when you zoom at 67%, it's 1:1

[user0]

182
Issue A1

test_img_A1.zip

(1.09 KiB) Downloaded 70 times

check both images in Viewer at 100% with win dpi scale 150%
4bit and 1bit - have different filters applied

1bit_vs_4bit.png (2.23 KiB) Viewed 2709 times

[xnview]

[user0]

Issue A
3. open image at 100% in Viewer
4. press B (and hold)
image will shift a bit, it looks like a filter is applied
occurs when any option other than None is selected for the Zoom Out (Settings>View)

yes, if you use win DPI > 150%, image at 100% will be scaled. Only when you zoom at 67%, it's 1:1

but why does Zoom-out filter affect image at 100% zoom?

in my understanding Zoom-out filter should only apply if you:
- set it <> Noone
- enable "High zoom quality" in Viewer (always enabled in Browser?)
- set image zoom <100%


it also looks like issue B is linked with the following issue that still exists:
1.5.0 - viewer - High zoom quality - None still affects image

[xnview]

If you use DPI scaling of 200%, and image zoom at 100%, you have not 1 pixel (image) on 1 pixel (display)

[user0]

copy of PM, so that everything is in one place

If you use DPI scaling of 200%, and image zoom at 100%, you have not 1 pixel (image) on 1 pixel (display)

right,
but I have issue with ranges at which you apply custom 'High zoom quality' filters which depends on win DPI scale.
In my understanding zoom-out/in threshold at which you apply filter should always be =100%.

lets compare behavior with other apps at winDPIscale 150%:

• ImageGlass and FastStone
  apply
  - zoom-out filters at 0-99% image zoom range -- as expected
  - zoom-in filters at 101-∞ image zoom range -- as expected

• XnViewMP
  apply
  - zoom-out filters at 0-149% image zoom range -- ???
  - zoom-in filters at 151-∞ image zoom range -- ???

Example

• ImageGlass
  Nearest Neighbour as 'None' option, which is a bit more explicit
  

• FastStone
  no zoom-in/out filter separation
  

ref
https://doc.qt.io/qt-5/highdpi.html
https://doc.qt.io/qt-6/highdpi.html
https://learn.microsoft.com/en-us/windo ... lity-scale