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If you change the screen size, the background color changes
Posted: Sun Dec 18, 2016 6:21 am
by c627627
If you change the screen size of this file in XnView 2.39 (latest version), the background immediately changes from transparent to black. Is this a bug?
EDIT: added original file:
Re: If you change the screen size, the background color chan
Posted: Sun Dec 18, 2016 8:30 am
by XnTriq
This is a known issue. Please increase the color depth (
Image »
32 bits) prior to resizing.
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 1:37 am
by c627627
Just wanted to tell you that XnView 2.39 > Image > 32-Bit is grayed out for this example image.
Other than opening it in another imaging program which does not have this issue, can I do anything else within XnView, since 32-Bit is grayed out?
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 3:15 am
by XnTriq
c627627 wrote:Just wanted to tell you that XnView 2.39 > Image > 32-Bit is grayed out for this example image.
Thanks for reporting back. Could you try the following configuration?
- Tools » Options...
- General » Operations » Ignore alpha channel = Off
- Read/Write » Read » PNG » Parameters » Compose image with transparency = Off
- Read/Write » Read » PNG » Parameters » Compose image with alpha (32bits) = Off
- Viewer mode: View
- Use transparent index (<=8bits) or alpha channel = On
- Use alpha channel = On
- Show Mask = Off
Test file:
CorsairRM850.png (163'824 bytes, 800×555 pixels, 8 bits/pixel, “
cheap alpha” transparency)
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 8:52 am
by c627627
As you can see, they were all already set as you instructed but this did not help.
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 4:00 pm
by XnTriq
c627627 wrote:As you can see, they were all already set as you instructed but this did not help.
Perhaps I misunderstood. When you say “change the screen size”, do you mean changing the screen resolution of your monitor/display or are we talking about
Image »
Resize...?
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 5:39 pm
by c627627
Image > Resize
Before and after screen shots:
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 9:45 pm
by XnTriq
This is really weird
As you can see in the screenshot,
Image »
32 bits isn't grayed out in my installation.
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 10:17 pm
by c627627
Resolved.
1. Go to original page:
http://www.corsair.com/en-us/rm-series- ... wer-supply
2. Right click on the power supply picture directly and save it to your computer.
3. Open it in XnView and before doing anything, go to XnView > Image > 32-Bits
Now it can be resized without a problem.
Why is this a requirement in XnView?
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 10:30 pm
by XnTriq
Thanks for your patience
c627627 wrote:Why is this a requirement in XnView?
Certain PNGs…
- 8-bit (indexed/paletted) with “cheap alpha” transparency
- greyscale with alpha channel
… aren't (fully) supported by
XnView's core library.
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 10:55 pm
by c627627
Is there an add-on to offer support?
Just out of curiosity what is the background for the lack of support for them?
Re: If you change the screen size, the background color chan
Posted: Mon Dec 19, 2016 11:30 pm
by XnTriq
c627627 wrote:Is there an add-on to offer support?
No
c627627 wrote:Just out of curiosity what is the background for the lack of support for them?
Unfortunately I can't answer this question because I'm not involved in the development of XnView.
Re: If you change the screen size, the background color chan
Posted: Tue Dec 20, 2016 12:12 am
by c627627
Thank you very much.