XnView Software

Hi )
If I use ACDSee Pro any version and I see JPEG2000 imagers , so I have this :
1) image size 4000x3000
2) in view set fit to window
and if window size or desktrop size 1000x750 , image load and view in progressive mode and decode as 1000x750 , if next I press full size - image reload with low speed
but in XnViewMP this work allways as if I load full size image and next do fit to window )
please , do progressive load images in JPEG2000 format with load if not need see full size )

Speed decoding JPEG2000 will be increase ?

The JPEG2000 format due to its complexity requires a lot of decoding, so opening files will inevitably generally take longer than for many other formats.

I don't know what the position is regarding the use of multiple cores, whether all available cores are already used by default?

JPEG2000 support open file two methods :
1) full size
2) only windows resolution
this means what for example you opened image 4096x2304 , but you window or desktop resolution 2560x1440 оr 1920x1080 , in this mode decode images not as 4096x2304 , but as 2560x1440 or 1920x1080 , because detail smaller , speed better )
By the way this can apply and to WebP and all decoders ) , I not see needs decode in full size and next fit to window )
Yes , if we want see full resolution , speed not will increase , but if we want see with resolution desktop or resolution window , this can increase speed )

Opening JPEG2000 images and maybe certain other formats at less than full resolution would require adding a setting, as presently provided for opening Camera RAW images, or in principle a pop-up when the file is loaded which might not work well.

While a file could no doubt be opened at a supported lower resolution, there might be an issue of whether opening the full image at an unsupported arbitrary resolution less than full resolution such as a screen size would actually be any quicker?

Pierre?