[Digikam-users] What am I doing wrong?

Stuart T Rogers stuart at stella-maris.org.uk
Sat Aug 30 18:23:56 BST 2014

Well I just tried adding a watermark in darktable and that ended up 
slightly larger at 7.0MB. Next was a manual watermark in digikam edit 
and that saved as 6.5MB.

So in batch mode there is something very strange going on to reduce the 
image so much. I believe there is a bug here....


On 30/08/14 17:47, Stuart T Rogers wrote:
> As I suspected my camera is not that bad at compression. My image with
> added watermark from GIMP is 6.2MB against the camera 6.7MB so in my
> view something is going wrong in Digikam. In GIMP I exported the image
> as 100% jpeg. I'll try imagemagik later.
> Stuart
> On 30/08/14 15:37, Stuart T Rogers wrote:
>> Well what I will do is use both imagemagic and gimp to put a watermark
>> on the image and see what file size I get from them. I think you might
>> be right but there is certainly still a doubt in my mind about this, not
>> sure that a camera would be that poor at compression especially a quite
>> recent one.
>> Stuart
>> On 30/08/14 12:40, Remco Viƫtor wrote:
>>> On Saturday 30 August 2014 10:18:40 Stuart T Rogers wrote:
>>>> Well not sure how to do this.... the only command used was a watermark
>>>> using text and no background at 20% size otherwise all default values
>>>> and I renamed them and stored them in the same folder (album). The
>>>> input
>>>> images were standard jpegs from my Pentax K500 and the saved files were
>>>> also jpegs. I looked for compression settings on the batch queue
>>>> manager
>>>> but cold not find any. Comparing the images afterwards showed the
>>>> renamed ones at about 1.8 or 1.9MB but the same pixel resolution as the
>>>> originals which seems to me that somewhere a compression setting of
>>>> less
>>>> than 100% was used but as I say I cannot find anywhere how to set this
>>>> for jpegs in the batch queue manager.
>>> That helps already.
>>> As you manipulate the image by adding the watermark, the image will
>>> have to
>>> be recompressed on saving. And like was said in a similar thread, a PC
>>> has
>>> more power than a camera, so it might do a better job at compressing w/o
>>> degradation.
>>> Also, looking at the images you  provided, I don't see any
>>> degradation. So
>>> if you agree on that point, there seems to be no problem. Unless,
>>> perhaps,
>>> when you have to do more editing on the images (but then why put the
>>> watermark already...)
>>> Remco.
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