Bug 245957

Summary:	Digikam shows pictures from PENTAX camera incorrectly in imageview
Product:	[Applications] digikam	Reporter:	Sebastian L <samlabc>
Component:	Preview-Image	Assignee:	Digikam Developers <digikam-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	caulier.gilles
Priority:	NOR
Version:	1.3.0
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed In:	2.0.0
Sentry Crash Report:
Attachments:	digiKam 1.4.0 K10D preview digikam shows very small preview with black bars

Description Sebastian L 2010-07-27 23:39:48 UTC

Version:           1.3.0 (using KDE 4.4.95) 
OS:                Linux

All images from a PENTAX K10D camera are shown or loaded incorrectly. The image looks like a strongly compressed preview picture with black bars at the top and bottom which is loaded instead of the correct image. This is also the case in Light Table view. The image is loaded and shown correctly in Gwenview and Digikam's image editor.

Reproducible: Always

Steps to Reproduce:
Open the attached file in digikam and click on the thumbnail.

Actual Results:  
A low quality and low resolution image with black bars at the top and bottom is shown when clicking on the thumbnail.

Expected Results:  
The correct high resolution image should be shown.

Comment 1 Sebastian L 2010-07-27 23:48:30 UTC

image file is too big for attachement (2.2 MB), you can download it here:
http://www.mal-was-anderes.de/_IGP7682.JPG

Comment 2 caulier.gilles 2010-07-28 09:45:00 UTC

Created attachment 49570 [details]
digiKam 1.4.0 K10D preview 

All work fine there, in preview mode and in editor. Nothing special. preview mode show a reduced size version of image (libjpeg feature) to speed up time loading. It's a option from digiKam setup dialog.

Gilles Caulier

Comment 3 Sebastian L 2010-07-28 10:24:18 UTC

Created attachment 49572 [details]
digikam shows very small preview with black bars

In your screenshot the reduced size preview shows the image correctly. In my digiKam 1.3 the preview image is show with black bars (see screenshot).
When enabling the option "Embedded preview loads full-sized images" in the setup dialog, the image is shown correctly.
I think it would be good to have a possibility to change between full-sized and reduced-size preview in the gui. Perhabs by clicking on the "Reduce Size Preview" text.
Another alternative could be to show a hint to the setup dialog where the preview mode can be changed when hovering over the "Reduce Size Preview" text.

Comment 4 caulier.gilles 2010-07-28 10:27:31 UTC

Sound like a libjpeg issue. Here i use 8.0 version.

Gilles Caulier

Comment 5 Sebastian L 2010-07-28 10:33:17 UTC

I'm using libjpeg8 8.0.1-1.9 from the opensuse 11.3 repositories

Comment 6 Marcel Wiesweg 2010-08-04 12:40:09 UTC

I can reproduce this here. The 640x480 preview is shown, which has these borders because the real image scales to 640x428.
Why is this preview shown? We require half the desktop size, let it be 1280:
  // require at least half preview size
  if (qMax(previews.width(), previews.height()) >= size / 2)
and 1280 / 2 = 640, so this hits.

I have a feeling that such a small preview usually has no good quality. Should we require full desktop size? or 80%? Or let the condition as is, but require a minimum of 1024px?

Comment 7 Marcel Wiesweg 2011-01-21 15:48:25 UTC

I just tested with 2.0, and the problem is solved. A lot of code has been changed in that area, so I assume it is fixed.