#! /bin/bash
# This script tests: pamchannel
# Also requires: pamtopnm


# Extract planes one by one.
# Convert output to pgm to make it identical to ppmtorgb3 output.

# $ ppmtorgb3 testimg.ppm ; cksum testimg.{red,grn,blu}
#
# 1571496937 33838 testimg.red
# 394856971 33838 testimg.grn
# 3164158573 33838 testimg.blu


# Test 1. red channel
# Should produce 1571496937 33838

pamchannel -infile testimg.ppm 0 | \
  pamtopnm --assume | cksum

# Test 2. green channel
# Should produce  394856971 33838

pamchannel -infile testimg.ppm -tupletype="GRAYSCALE" 1 | \
  pamtopnm | cksum

# Test 3. blue channel
# Should produce 3164158573 33838

pamchannel -infile testimg.ppm 2 | \
  pamtopnm --assume | cksum