> Other that Ghostscript's compression perhaps not being > as good, so the image grows in bytes, does this matter? > The resulting pixels are the same?
If ghostscript uses lossy compression, then the pixels will be similar but not *exactly* the same. Possibly ghostscript might also apply color management while decompressing and recompressing the image, but I don't really know whether or not it does this. > I often run ps2pdf(1) on PDF files here, e.g. from -Tpdf, > as it often makes them use fewer bytes. Unless you tell it not to do so, ghostscript may downsample and/or compress images lossily, so the smaller file size could be achieved at the expense of reduced image quality. If your document contains only text then image compression is not relevant, but a smaller file size might also be due ghostscript subsetting the embedded fonts.