[scribus] Image cropping

[Peter Nermander]

> afaik, cropping a jpeg is a lossless operation: so there is no change between the original image and the cropped one in the pdf...
> or, at least, it can be done in a lossless way and without resampling it.

Yes, it can be done without resampling, but not without recompression.

The way a JPEG is compressed it has to be recompressed after any
change. Change one pixel and the image has to be recompressed. That is
why using JPEG as a working format during image editing is no good.

It seems however it is possible to do lossless cropping if you crop
along the borders of the "blocks" the image is made up of.

And if that is true that would probably be a working solution.It would
of course mean that the cropped images might become a little bigger
than the frame, but not more than 30 pixels (assuming worst case with
16 pixel blocks, giving 15 pixels on each side).

/Peter