gen dummy image iwth difference pattern

generator.sh

for i in $(seq $1 $2)
do
	if test -e $i.jpg ; then
		echo "already created $i"
	else
		convert -size 50x50 xc: +noise Random -virtual-pixel Tile -blur 0x5 \
		-auto-level -separate -background white \
		-compose ModulusAdd -flatten -channel G -combine +channel \
		-set colorspace HSB -colorspace RGB   tile_diag_source.jpg

		convert tile_diag_source.jpg     \( +clone -transpose \) \
		\( +clone -sparse-color voronoi '%w,0 white 0,%h black' \) \
		-composite \
		\( +clone -flop -chop 1x0 \) +append \
		\( +clone -flip -chop 0x1 \) -append \
		-resize 4000x3000 \
		tile_diag_mirror.jpg

		echo create $i

		convert tile_diag_mirror.jpg \
		-font Arial -pointsize 720	 \
		-draw "gravity center fill white  text 0,0 '$i'" \
		 $i.jpg
		
	fi
done