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

[lffs]

Subject: 1.0: Checking or unchecking (Menu: View->Use alpha channel), (Menu: View->Show alpha) has no effect when using "High zoom quality".

XnView: MP 1.0 64 bit
OS: Windows 10 21H2 64bit

When viewing a png with transparency and using "High zoom quality", checking or unchecking (Menu: View->Use alpha channel), (Menu: View->Show alpha) has no effect. (This happens sometimes, not on every image. I will upload a sample image)

Effect: When using "High zoom quality", checking or unchecking (Menu: View->Use alpha channel), (Menu: View->Show alpha) has no effect. Please see the attached image.

To reproduce:
1. open a png image with transparency
2. Turn on "High zoom quality", check or uncheck (Menu: View->Use alpha channel), (Menu: View->Show alpha)
3. Problem may occur: The display may change.

Actual behaviour (bug): When using "High zoom quality", checking or unchecking (Menu: View->Use alpha channel), (Menu: View->Show alpha) has no effect.

Expected behaviour: When using "High zoom quality", (Menu: View->Use alpha channel), (Menu: View->Show alpha) options work fine.

Screenshot 1: High zoom quality (ON), Show alpha (ON)

high_zoom_quality_on.jpg

Screenshot 2: High zoom quality (OFF), Show alpha (ON)

high_zoom_quality_off.jpg

Sample images:

sample1.png

[XnTriq]

Confirmed

Only if Bilinear is chosen as the algorithm for High zoom quality in Tools → Settings… → View → View, everything works as expected.

[xnview]

do you have always the problem in 1.4.2?

[XnTriq]

do you have always the problem in 1.4.2?

XnView Classic works fine.

[xnview]

do you have always the problem in 1.4.2?

XnView Classic works fine.

in MP?

[XnTriq]

in MP?

There's a new problem in v1.4.2 if High zoom quality in Tools → Settings… → View → View is set to Zoom-out & Zoom-in and Bicubic:

zoom_100.png

zoom_150.png

[xnview]

There's a new problem in v1.4.2 if High zoom quality in Tools → Settings… → View → View is set to Zoom-out & Zoom-in and Bicubic:

I can't reproduce, could you send me the image used?

[XnTriq]

I can't reproduce, could you send me the image used?

It's the file posted by the thread starter (lffs): sample1.png

[xnview]

I can't reproduce, could you send me the image used?

It's the file posted by the thread starter (lffs): sample1.png

i can't reproduce, do you use windows font scaling?

[XnTriq]

i can't reproduce, do you use windows font scaling?

Yes (125%). When I turn it off (100%), the problem does not occur.
FYI: Zoom on HiDPI screen: 1 image pixel equals 1 screen pixel in Tools → Settings… → View → View is activated.