"High quality Zoom-out" lanczos-spline-bicubic filters don't work
Moderators: XnTriq, helmut, xnview, Dreamer
"High quality Zoom-out" lanczos-spline-bicubic filters don't work
XnView: Version 0.99.1 64bits (Sep 23 2021) - thanks for new version with speed improvement.
OS: Windows 10 64bit
Bug: "High quality zoom-out" (image reduction) settings (settings -> view -> high quality zoom-out) for filters called lanczos, spline and bicubic don't work.
They all look like billinear. Only "High quality zoom-in" (image enlarge) works as expected.
This bug doesn't exist in Version 0.98.2 64bits (Feb 19 2021), before "2043: [New] Zoom out filter (Bicubic, Spline, Lanczos)" was introduced.
For some reason, Version 0.98.2 has "1958: [New] Zoom-in filter (Bicubic, Spline, Lanczos)" feature, but actually this feature is zoom-out (reduction).
Version 0.99.1 has "2043: [New] Zoom out filter (Bicubic, Spline, Lanczos)" feature, but actually this feature is zoom-in (enlarge).
Image compare lanczos4 algorithm for "zoom-out" at 99% level. Look only at 100% in image viewer. Version 0.99.1 at the right is blurry.
Test images from:
http://www.falklumo.com/lumolabs/articles/sharpness/
OS: Windows 10 64bit
Bug: "High quality zoom-out" (image reduction) settings (settings -> view -> high quality zoom-out) for filters called lanczos, spline and bicubic don't work.
They all look like billinear. Only "High quality zoom-in" (image enlarge) works as expected.
This bug doesn't exist in Version 0.98.2 64bits (Feb 19 2021), before "2043: [New] Zoom out filter (Bicubic, Spline, Lanczos)" was introduced.
For some reason, Version 0.98.2 has "1958: [New] Zoom-in filter (Bicubic, Spline, Lanczos)" feature, but actually this feature is zoom-out (reduction).
Version 0.99.1 has "2043: [New] Zoom out filter (Bicubic, Spline, Lanczos)" feature, but actually this feature is zoom-in (enlarge).
Image compare lanczos4 algorithm for "zoom-out" at 99% level. Look only at 100% in image viewer. Version 0.99.1 at the right is blurry.
Test images from:
http://www.falklumo.com/lumolabs/articles/sharpness/
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
"High quality zoom-out" use always bilinear, the setting is for High quality zoom-in
Pierre.
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
in 0.98.2, it was a bug
Pierre.
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
I dont know, how it is bug, if:
Version 0.98.1, where high quality lanczos-spline-bicubic filters was officially introduced, shows lanczos zoom out perfectly.
Only starting with 0.98.3, when high quality lanczos-spline-bicubic "zoom out" was introduced, also bug was introduced, which destroy ACTUAL high quality lanczos-spline-bicubic zoom out and replaced it with high quality lanczos-spline-bicubic zoom in. In photography sharp zoom out is much more important, than sharp zoom in. Bicubic-spline-lanczos algorithm recommended for zoom out. And billinear recommended for zoom in. Xnview not just has this bug, but works not as expected by image editors and in pro photo, using resource-cheap billinear zoom out as 1990-early 200X programs.
Please fix this bug, or return back destroyed "Bicubic-spline-lanczos zoom out", so xnview will have Bicubic-spline-lanczos algorithms for both zoom in and zoom out. Version 0.98.2 is latest, which I can use. 0.99.1 is blurry and ugly, it and newer versions will be abandoned by me and other users (to which high quality matter), until bug will be fixed.
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
I second this. It is very annoying that the shown scaling options do nothing for downscaling.
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
Thanks to your detailed description I can reproduce the problem.
Pierre.
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
This problem is supposed to be fixed in XnView MP 1.5.0 beta. Please check and confirm the bug fix here.
Pierre.
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
Now is a big problem.
When I zoom picture more than 100%, image is cutting on right and down side by few %
It works when zoom HDPI screen is setting off.
[update]
Windows 11 / display resolution 1920x1200 / win scaling 110%
When I zoom picture more than 100%, image is cutting on right and down side by few %
It works when zoom HDPI screen is setting off.
[update]
Windows 11 / display resolution 1920x1200 / win scaling 110%
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
which zoom settings do you have?
Pierre.
Re: "High quality Zoom-out" lanczos-spline-bicubic filters don't work
Problem is no more here when 'Zoom on HiDPI screen: on'?
Pierre.