test/ppmdim.test


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#! /bin/bash
# This script tests: ppmdim
# Also requires: pamfunc pnmarith pamarith pamsumm

  alias ppmdim="${PBM_TESTPREFIX}ppmdim"
  alias pamfunc="${PBM_BINPREFIX}pamfunc"
  alias pamsumm="${PBM_BINPREFIX}pamsumm"
  alias pnmarith="${PBM_BINPREFIX}pnmarith"
  shopt -s expand_aliases

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}
  pnmarith -diff ${dim1_ppm} ${dim2_ppm} | \
    pamsumm -mean -brief | \
    awk '{print $1<0.75 ? "ok" : "fail"}'
  done

rm ${dim1_ppm} ${dim2_ppm}