Use these commands to generate testdata: tiffcp -s -r 64 video-001.tiff video-001-strip-64.tiff tiffcp -t -l 64 -w 64 video-001.tiff video-001-tile-64x64.tiff R=golang-dev, nigeltao, bsiegert CC=golang-dev https://golang.org/cl/13453043
Add a "compare to golden PNG" test for BMP and TIFF. R=rsc CC=golang-dev https://golang.org/cl/5601054