Bug 63151

As I remeber, some time a go (in KDE 3.0 ?) jpeg quality was better. If no configurable quality setting is made, then rising jpeg quality would be great. In Gimp I set jpeg quality to 80 or 85, what gives good results. It is possible to reduce quality usin other graphical apps, if it is need. ;)

A Kpart in KDE for selecting image file type compression would be appreciated if available for all KDE application.

Eg: when saving a file from Kuickshow, this is the same problem, we can't select the compression level. I guess there are many other apps where it would be cool to have this feature too. You tell that we can use an image manipulation program but I'll give you the example of kuickshow : I use kuickshow to browse my photos and when I have a photo token in landscape but that should be rotated 90° I can use kuickshow to do this (this is cool cause I'm do this operation and continue to browse without having to open Gimp) but when I save it, the compression doesn't fit my need and there's no way to set the compression level, so this is useless for me.

So I get that if all KDE programs would have the benefit of a KPart that allows to save a picture with a particular compression, ksnapshot would use it and it would be ok.

An option to save internet optimized PNG-images (colors reduced to an 8bit-palette without dithering, maximum compression, interlacing) is missing too.

*** This bug has been confirmed by popular vote. ***

Both Bug 78802 and Bug 108266 are about the same issues.

I'd like to reduce the palette sometimes. I'd like to reduce the number of used colors. When I take a snapshot of a Web site, I don't really need a 24-bit file. 

I'd like to reduce the number of used colors, too. I make a lot of snapshots to use in my blog - 500 KB PNG is too big when actually only ~60 colors are used.

This is all handled by the standard kdelibs functionality, reassigning there.

Since this bug was originally about Ksnapshot, moving to Spectacle, its replacement.

Git commit 9561610552c78ae7cd9dce572ca7d241765532c1 by Nate Graham, on behalf of Nils Rother.
Committed on 07/03/2019 at 20:36.
Pushed by ngraham into branch 'master'.

Add Compression Quality slider for lossy formats

Summary:
FIXED-IN: 19.04.0

This adds a slider to set the compression quality for lossy file formats
to the settings page, so users can set it themselves instead of having
to just accept the (in my opinion too low) default value.
The slider defaults to a quality level of 90.

A couple of notes:

  -When adding the slider to the 'Save'-page layout I noticed that the
   bottom of the help text for the filename chooser got cut off because
   the window was too small. I tried to figure out how to get the settings
   page to scroll but couldn't quite get it working. Instead I resorted to
   simply increasing the default size of the settings window just enough to make it
   fit. If someone with more experience in Qt than me can get the page to scroll OR
   can suggest a better way to display the formatting help text (which I feel
   takes up too much of the page), that would be marvelous.

  -When saving an image at full (100) quality it still looks a bit washed out and
   fuzzy, when compared to, for example, saving the image as png and converting it
   to JPG in gimp at full quality. This might be an issue with QImageWriter unless
   this is the desired behaviour? I haven't looked into it too much, just something
   I've noticed when testing

Test Plan:
This setting can be found under
Configure -> Save -> Compression Quality
{F6669261}
Set the default file type to JPG, adjust the slider and export to an image-viewer
of your choosing (eg. feh) to see how it affects image quality.

Reviewers: #vdg, #spectacle, davidre, ngraham

Reviewed By: #vdg, #spectacle, davidre, ngraham

Subscribers: ngraham, davidre, #spectacle

Tags: #spectacle

Differential Revision: https://phabricator.kde.org/D19591

M  +1    -0    src/ExportManager.cpp
M  +36   -0    src/Gui/SettingsDialog/SaveOptionsPage.cpp
M  +2    -2    src/Gui/SettingsDialog/SaveOptionsPage.h
M  +1    -1    src/Gui/SettingsDialog/SettingsDialog.cpp
M  +13   -0    src/SpectacleConfig.cpp
M  +3    -0    src/SpectacleConfig.h

https://commits.kde.org/spectacle/9561610552c78ae7cd9dce572ca7d241765532c1