Most scaling algorithms remove alpha channel when resizing an image

damian101 · Post by **damian101** » Sat Jan 09, 2021 9:33 am

With scaling methods Hermite, Gaussian, Bell, BSpline, Mitchell, Lanczos and Hanning the alpha channel gets removed when resizing an image.
Only Nearest Neighbor and Bilinear work as expected and preserve the alpha channel.

Post by **xnview** » Thu Jan 14, 2021 8:43 am

i can't reproduce, could you send me a sample image?

damian101 · Post by **damian101** » Sun Jun 13, 2021 1:30 pm

xnview wrote: ↑Thu Jan 14, 2021 8:43 am i can't reproduce, could you send me a sample image?

Yes, I also could not reproduce this issue until I found the image I originally had the problem with. It's just 17x17 pixels in size, but it's not the size that causes this, since the issue can not be reproduced after reencoding the image with XnConvert.

Post by **xnview** » Mon Jun 14, 2021 8:27 am

I can't reproduce with the file, could you post a screenshot of resize dialog?

damian101 · Post by **damian101** » Fri Sep 10, 2021 12:21 am

xnview wrote: ↑Mon Jun 14, 2021 8:27 am I can't reproduce with the file, could you post a screenshot of resize dialog?

Can't reproduce either now. I'm on Arch Linux, no idea why it did not work a few months back. Everything's working fine now.

XnView Software

Most scaling algorithms remove alpha channel when resizing an image

Most scaling algorithms remove alpha channel when resizing an image

Re: Most scaling algorithms remove alpha channel when resizing an image

Re: Most scaling algorithms remove alpha channel when resizing an image

Re: Most scaling algorithms remove alpha channel when resizing an image

Re: Most scaling algorithms remove alpha channel when resizing an image