Ok, so from the command line....you might try sips: $> sips --resampleHeightWidth <height in pixels> <width in pixels> Sips works for most raster image format

Ok, so from the command line....you might try sips: $> sips --resampleHeightWidth <height in pixels> <width in pixels> Sips works for most raster image formats. Guess I need to update and re-post my OS X utility help page. There are a lot of tools buried in OS X that are quite useful.