Hi,

I'm trying to resize image for mplayer overlay usage. I'm using "convert -resize" from Imagemagick. My problem is that after resize image doesn't have the original color depth nor palette.

I'm able to resize image correctly if I manually set depth and type, but this is not working when I have to resize images with different palettes.

Is there any CLI tool or specific convert option to resize image with keeping all the other image related setting as original?

Br,

-Timo-

Image scaling is not at all a trivial thing.
Due to interpolation, the color table for the result
cannot be the same as that of the input. The trick
is not to use palette-based images in the first place.

In professional applications, the mother images are
kept in super quality (3x8 RGB) and all the web-faced
derivatives of the mother image are in some reduced or
mangled form (jpg,png). I did not even know palette-based png
existed. The extermination of GIF with its simple color table
apparently has not exterminated that bad habit.

You may want to use the netpbm package for storing images in
raw RGB format (.ppm). You can rescale (and re-palette if you want)
in whatever way you like, then use ImageMagick convert to
get at the required output format.

Also: consider jpeg: if resizing is your thrill, .jpg
is more convenient and better than .png. A JPEG which is
live resized via html < img src = is neater in many browsers
than a resized png.

Look for:
pnmscale
pnmcolormap
pnmremap
pnmquant
pnmdepth
(etc.)