[magick-users] convert -crop image quality question

[Gabe Schaffer]

On 11/5/06, Anthony Thyssen <anthony at griffith.edu.au> wrote:
> "J. Young" on  wrote...

> | convert bigpage.jpg -crop 50%x0+0+0 page1.jpg
> | convert bigpage.jpg -gravity East -crop 50%x0+0+0 page2.jpg
> |
> | So this works ok, but is it a lossless operation as far as image
> | quality?  If not, could someone recommend a lossless equivalent?
> |
> JPEG to JPEG is always lossless in IM.

Always lossless? Did you mean never?

> and there does not appear to be a lossless cut or crop opperation
> provided by jpgtran.    I'd say you best bet is to just not save back to
> JPEG, or upgrade to using the new JPG2K library.

The version of jpegtran on my machine (from 1998) has a crop feature,
and I'm pretty sure that jpegtran doesn't even have the capability to
perform lossy operations.

I'm going to bet that jpegtran -crop is exactly what the OP wants.

GNS