Bug: Canon CR2 Embedded jpeg are not correctly displayed

[sahlirc]

Code of Conduct

• I have read this document and I accept the conditions

Search previous report

• I have searched my issue

Computer's operating system

Linux

What GPU do you have ?

Nvidia

Ansel version

Ansel-0.0.0+1880.g22d0080-x86_64 and later

Type of binary

Pre-built packages provided by the Ansel project (.AppImage, .EXE)

What happened?

The embedded jpeg are too dark (close to black) in the thumbnails displayed in the import module as well as in the Lighttable.

How it should be (with version 1872):

How it is shown (version 1880):

"Show embedded jpeg" in the lighttable set to "always" displays the original jpeg, hence be almost black. However, if set to "raw" one can see the image and treat it in the darkroom.

Output_1872.txt

Output_1880.txt

Does your problem occur with OpenCL enabled ?

Yes

Does your problem occur with OpenCL disabled ?

Yes

Previous Ansel version that use to work

Ansel-0.0.0+1872.gb87692e-x86_64 and earlier

Output of ansel -d all

Backtrace

[Jiyone]

Have you tried with the last build or the build 1975 ?

[sahlirc]

I have tested all AppImage releases until I found the last that worked (1872) and the first that didn't (1880). Please note that versions prior to 1872 are OK, while those after are not. So version 1975 in Linux does not work, while the same version in Windows does work! This looks like a Linux problem (pour une fois ???).

[sahlirc]

It may have something to do with the size of the thumbnail. Here in the darkroom (I have used the last Appimage 2013 for this), the image being edited is OK, yet the small thumbnail in the bottom panel looks too dark.

Update the size of the bottom panel and it looks OK from a specific size.

I'll check if this is reproducible in the Lighttable as I remember an old bug I mentioned having to do with thumbnails being displayed differently according to the number of columns set in the Lighttable.

[sahlirc]

I have used the last AppImage (2013) as well as 1975 and 1880 in Linux to confirm that the thumbnails are rendered either too dark or OK beyond a specific size (defined by the number of columns for each specific screen, for my 27" screen the threshold is at 7 columns or lower for a correct display). Please note that this may vary from one version to the other. Using "Execute/Purge selected thumbnails from cache" (see issue #519) affects this in the Lighttable. Version 1872 renders the thumbnails perfectly, be it in the import module (I cannot modify the size of the thumbnail so cannot comment on whether it would be ok beyond a threshold) or in the Lighttable.

[sahlirc]

This is really weird. The initial thumbnail size in the lighttable dictates how the images are rendered (using the embedded jpeg). If large enough, they look fine and one can make them smaller by increasing the number of columns. If small initially, then the whole session is fraught with this issue. Suffice to close Ansel in the lighttable with images at the threshold size for correct display, then the next session will display images correctly independent of the thumbnail' size afterwards. I use this as a workaround. This still applies to today's version of Ansel: 2ff9984.