XnView Software

Win11 23H2 / AMD RYZEN / 32 GB RAM

There is big image Van Gogh from Wikipedia https://upload.wikimedia.org/wikipedia/ ... roject.jpg (30,000 × 23,756 / 205.1 MB).
It is opening OK in XnView MP.
But when I try to enlarge the image by 200%, it only enlarges half, the lower half is a quirk. Saving PNG file gives only half source the image, the second is black.

IMHO, it's problem with allocate bigger memory on Windows (clear installation, not on virtual machine).

Confirmed, my lower half is completely black!
I won't bother saving as format as it will be the same as what I'm seeing now

what do you have in 'Settings>View - high zoom quality'?

xnview wrote: Tue Apr 09, 2024 6:08 am what do you have in 'Settings>View - high zoom quality'?

Bicubic in both Out/In.

try bilinear, take less memory

I'm afraid there has been a misunderstanding.

When I wrote "enlarge" I didn't mean pressing the '+' key, but 'Shift'+'S' and setting here 200% enlarge. After this operation that only the upper half is correct and the lower half is incorrect.

yes. try bilinear, take less memory

In fact, when I set the magnification type to bilinear, the image enlarged correctly.
However, the idea is to enlarge the image using any technique, e.g. Mitchell, Lanczos.
I have enough memory, that's not the problem. IMHO, it is a problem of proper memory allocation, which in certain circumstances (large image,
zoom method) is poorly managed.

Kadet wrote: Wed Apr 10, 2024 11:39 am In fact, when I set the magnification type to bilinear, the image enlarged correctly.
However, the idea is to enlarge the image using any technique, e.g. Mitchell, Lanczos.
I have enough memory, that's not the problem.
Big_image.jpg
IMHO, it is a problem of proper memory allocation, which in certain circumstances (large image,
zoom method) is poorly managed.

Ok, the bilinear function is not the same for other filters. But i can't reproduce. In 100%, the picture is correctly displayed (with bicubic), and not in 200%. You can reproduce each time?

to reproduce:
0. clean unzipped version
1. open image
2. press SHIFT+S to open Resize Image
- set Mode to %, value to 101%
- set Method to.. see below
- press OK
get image with black line in the bottom, sometimes crash
ps: memory consumption same as Kadet's - never come to 100% (I have 32Gb as well)

xnview wrote: Wed Apr 10, 2024 1:07 pm Ok, the bilinear function is not the same for other filters. But i can't reproduce. In 100%, the picture is correctly displayed (with bicubic), and not in 200%. You can reproduce each time?

Yes, it happens every time.
Height black bottom is depending on % zoom. For 200% it's 50%. For 150% it's 25%. For 105% is a little.
When I try 110% program crash me every time. I click Update to send You info from crash.

I hope You find the bug.

Edit.
PS. When I saved a zoomed image by bilinear to png I can't read it - not in XnView, not in Windows Photo.
PS2. Save As jpegli is OK.

Thanks to your detailed description I can reproduce the problem.

This problem is supposed to be fixed in XnView MP 1.7.2. Please check and confirm the bug fix here.

All is OK.