Image goes bad after rotation/resize

[anthony]

Resize in Im is probably one of the best general image resize operations there is. You can shapren the image slightly afterward if you like a small improvement to bring it in line with Photoshop.

The default rotate in IM is not so good, a better one is part of the new general -distort function...
See -rotate of a thin line
http://www.imagemagick.org/Usage/distorts/#rotate_line
and rotate with various interpolation settings using -distort (or -fx)
http://www.imagemagick.org/Usage/misc/#interpolate_line
Which shows a vast improvement.

There are better 'filters' that can be used for the interpolation, and these are being looked into at this very moment, so even better improvement s may be forth coming.

One user recently pointed out a comparision of resize methods, in which IM with a little sharpening beat all other programs tried...
http://www.xs4all.nl/~bvdwolf/main/foto ... ample1.htm
and another looking at resizing compared to photoshop
http://www.xs4all.nl/%7Ebvdwolf/main/fo ... sample.htm
that also put IM as having the superior resize downward algorithm, especially with the default Lanczos filter.