Re: [gthumb-list] Bug: EXIF orientation is broken after resize



Il 02/02/2013 20:51, damien clochard ha scritto:
Le 02/02/2013 04:36, Rennie deGraaf a écrit :
On 01/02/13 12:54 PM, damien clochard wrote:
Le 29/01/2013 16:30, Dr. Michael J. Chudobiak a écrit :
the orientation field makes sense only in the original image, when you
create a new image it is better to reset it.

Sorry again but I don't understand this logic. I don't see how resetting
the orientation after a resize operation is useful to anyone. These are
two different things. My understanding is that gthumb should keep this
orientation when user ask for a resize.

Am I correct ?

No. The orientation tag is taken into account when the image is loaded
into memory.

The resize happens on the image in memory.

Yes I am aware that the transformation are executed "in memory" and not
directly on disk :-) Anyway I don't see how this is related with the
issue I described.

As I understand it (forgive me if this has changed since I last looked
at the code), gThumb rotates every image that it loads to the "top-left"
orientation.  If it subsequently saves the image, it uses the rotated
image data and sets the EXIF tag to "top-left" to ensure that the tag
matches the data.


Ok thanks for your explanations. I understand now that my problem has
nothing to do with the resize operation. I still think that The Gimp has
a better approach for this rotate-or-keep-exif-tag issue but that's not
the subject here. Anyway let's close this discussion, and go back to my
initial problem.

The scenario is even simpler now :

1/ Open this file : http://nawak.taadeem.net/DSC_1114.orig.JPG
2/ Save it as DSC_1114.png

The original photo is in portrait format.

The NIKON file has the following tags :

   X Dimension : 2896
   Y Dimension : 1944
   Orientation : left, bottom

When Gthumb displays the picture as a thumbnail it's in portrait format.
When the picture is in full screen mode is displayed in landscape.

The PNG file has the following tags :

   X Dimension : 2896
   Y Dimension : 1944
   Orientation : top, left

see http://nawak.taadeem.net/DSC_1114.png

I used gThumb 3.1.3

I cannot reproduce the problem, the image is always in portrait mode to me.

- Paolo




[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]