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On 2006-08-13T17:48:25+00:00 Matěj Laitl wrote:
Version: 1.3.92 (using KDE KDE 3.5.3)
Installed from:Gentoo Packages
Compiler: GCC 4.1
OS:Linux
This bug applies to *SOME* JPEGs.
When I try rotate a jpeg image, it displays correctly.
But when I save it, a thin row of pixels (usually 5 to 10 pixels thick -
depends on the image) is magically transfered from top to bottom. (or other
directions)
If I rotate the original image, but save it in PNG instead of JPEG, the
problem is gone.
This problem also aplies to Flip and Mirror operations.
This seems related to new JPEG lossles rotation capability introduced in
1.3.92
I'm gonna upload images where this occurs.
I checked it in GV versions: 1.3.92 and SVN revison 572689 (dated
2006-08-13)
Reply at:
https://bugs.launchpad.net/ubuntu/+source/kdegraphics/+bug/29627/comments/19
On 2006-08-13T17:51:06+00:00 Matěj Laitl wrote:
Created attachment 17356
Original Image
Reply at:
https://bugs.launchpad.net/ubuntu/+source/kdegraphics/+bug/29627/comments/20
On 2006-08-13T17:54:22+00:00 Matěj Laitl wrote:
Created attachment 17357
Rotated Image
Note the image only seems to be B/W. Technically it's full RGB.
PS: Like the girls? ;-)
Reply at:
https://bugs.launchpad.net/ubuntu/+source/kdegraphics/+bug/29627/comments/21
On 2006-09-19T02:45:10+00:00 Danakil-kde wrote:
Same problem here with this picture :
http://danakil.free.fr/linux/bug_if_rotated.jpg
http://danakil.free.fr/linux/right_rotated.jpg - bug
I don't know if this is important but this picture was resized with the
Resize images... kipi plugin
Reply at:
https://bugs.launchpad.net/ubuntu/+source/kdegraphics/+bug/29627/comments/22
On 2006-10-31T19:30:13+00:00 Matěj Laitl wrote:
Still occurs with gwenview 1.4.0 using KDE 3.5.5
Reply at:
https://bugs.launchpad.net/ubuntu/+source/kdegraphics/+bug/29627/comments/23
On 2006-11-03T15:43:12+00:00 Aurélien Gâteau wrote:
This is because the JPEG image dimensions are not a multiple of the MCU
size see [1] for an explanation). In this case, there are three
solutions to perform a rotation:
1: Apply a lossless rotation, keeping the odd pixels around. Rotating
the image the other way will give you back the original image.
2: Apply a lossless rotation, but trim the offending pixels, in your
case this would reduce the height of the rotated image from 900 to 896.
Rotating the image the other way won't give you back the original image.
3: Apply a lossy rotation, which would give a correct image, but would
probably loose some details.
For now, Gwenview adopts a conservative behavior and use #1. What do you
think should be done? let the user choose the solution? select #2 or #3
without asking?
If you want to try #2, edit imageutils/jpegcontent.cpp, find the line
that says:
transformoption.trim = false;
and change it to:
transformoption.trim = true;
[1]: http://www.impulseadventure.com/photo/jpeg-minimum-coded-unit.html
Reply at:
https://bugs.launchpad.net/ubuntu/+source/kdegraphics/+bug/29627/comments/24
On 2006-11-03T17:48:21+00:00 Matěj Laitl wrote:
Oh, thanks for the nice explanation...
Is it possible to apply a lossy rotation only to the partial MCUs on the
sides, while keeping lossless for the rest? Looks like a good compromise
for me.
Trimming an image a little (the worst case would be 15 pixels) is not
IMHO transparent for user... It alters composition or user-made margins
etc.
How often you rotate save multiple times? I prefer small quality loss
to erasing a small part of image.
(maybe stupid) idea: If it saved rotated JPEGs with slightly lower
compression ratio, would it eliminate the quality loss?
Reply at:
https://bugs.launchpad.net/ubuntu/+source/kdegraphics/+bug/29627/comments/25
On 2006-11-03T18:00:35+00:00 Matěj Laitl wrote:
Oh, now I know that i can't be only partially lossy.
So the best solution IMHO:
offer 2 or 3 to an user, and add configuration options:
always 2.
always 3.
ask before each save of rotated odd-sized jpeg.
what about the maybe stupid idea?
Now i will only resize my
