$Id: image.txt 1869 2008-06-01 19:29:34Z mjs $
This is probably caused by some embedded colour space information; see below for how to remove this.
(You might want to do this to ensure that PNG colours match CSS colours.)
$ pngcrush -rem gAMA -rem cHRM -rem iCCP -rem sRGB infile.png outfile.png
See
http://hsivonen.iki.fi/png-gamma/
(Or, convert to GIF...)
$ pngcrush image.png -rem alla -reduce result.png
See
http://developer.yahoo.net/blog/archives/2008/03/yahoos_latest_p.html
See
http://www.cit.gu.edu.au/~anthony/graphics/imagick/
Text on command line:
$ convert -background white -fill black -font ~/Library/Fonts/P22UNDER.TTF \
-transparent white -pointsize 72 label:"Holloway Rd" holloway.gif
Text in file:
$ convert -background white -fill black -font ~/Library/Fonts/P22UNDER.TTF \
-transparent white -pointsize 72 label:@holloway.txt holloway.gif
(This does do anti-aliasing, but I couldn't get a separate "matte" colour working...)
HOWTO: Crop an image (ImageMagick)
$ convert -mattecolor black src.jpg -crop 70x70+0+0 -size 70x70 +repage dst.jpg
ImageMagick 6+ use the "new" command-line parameter handling--the hard bit is to make sure the different bits are specified in the right order!
(Known as "Color to Alpha" in gimp.)
Use imagemagick:
$ convert -transparent white foo.png bar.png
(I don't know how to do this with Pixelmator.)
HOWTO: Strip comments from JPEGs (jpegtran)
$ jpegtran -copy none -optimize -perfect src.jpg dst.jpg
See
http://developer.yahoo.net/blog/archives/2008/03/yahoos_latest_p.html