Re: [NTG-pdftex] Creating identical PDF files with different pdfTeX runs

On Thu, 16 Mar 2006, Frank Küster wrote:

Hartmut Henkel wrote:

Yes, we definitely need the original file.

...

Maybe some crosscorrelation between images with some given tolerance limit would be safer.

Any hints what I could use for such a purpose?

just found from Netpbm: NAME pnmpsnr - compute the difference between two portable anymaps SYNOPSIS pnmpsnr [pnmfile1] [pnmfile2] DESCRIPTION Reads two PBM, PGM, or PPM files, or PAM equivalents, as input. Prints the peak signal-to-noise ratio (PSNR) difference between the two images. This metric is typically used in image compression papers to rate the distortion between original and decoded image. And in ImageMagick there is a -compose operator with Difference and Multiply option. Regards, Hartmut