#! /bin/sh # This script tests: ppmdim # Also requires: pamfunc pamarith pamsumm tmpdir=${tmpdir:-/tmp} # Compare ppmdim and pamfunc with various dim factors # Due to the difference in rounding methods, pamfunc produces slightly # brighter images, by about 0.5 per pixel. # If the mean difference is between 0 and 0.75 we consider the output # normal. This works for dim values up to 0.994 . dim1_ppm=${tmpdir}/dim1.ppm dim2_ppm=${tmpdir}/dim2.ppm for i in 0.125 0.25 0.5 0.75 0.1 0.0117 0.2 0.4 0.333 0.666 0.8 0.9 0.95 do ppmdim $i testimg.ppm > ${dim1_ppm} pamfunc -mult=$i testimg.ppm > ${dim2_ppm} pamarith -diff ${dim1_ppm} ${dim2_ppm} | \ pamsumm -mean -brief | \ awk '{print ($1<0.75) ? "ok" : "fail"}' done rm ${dim1_ppm} ${dim2_ppm}