[magick-users] JPG compression levels

[Yuval Levy]

Hallo Wolfgang,
thank you for your reply.

Wolfgang Hugemann wrote:
>> specifically I would like the edges of an image to not be compressed
>> at all.
> 
> AFAIK, the definition of the JPEG standard does not comprise such a
> feature. This is only offered by JPEG 2000.

I am a newbie, so I do not know if this is the same, but Adobe Fireworks
claims to do something like that, and
<http://www.xat.com/jpegopt/index.html> ("Selective optimization -
compress some areas more than others") too.

If I am not mistaken, JPEG compresses images in blocks of 8x8 pixels?

The best idea I could come up with so far with is to create the
different 8x8 blocks individually with different target compressions and
then use the -drop option of jpegtran to merge them into a single image
without loss/recompression. I will be testing the idea in the coming hours.

Yuv