Making place holder tiles for a montage

make_blank_tiles.sh

#!/bin/bash
#Creates blank white tiles for a 16x8 grid
#white, 1204x864 unless otherwise specified.
#Using hex colors requires quotes. ie. "#F0F0F0"
#REQUIRES IMAGEMAGICK. 


#the first parameter passed to the shell script
#will be the width of the grid needing tiles
WIDTH=$1;

#the second parameter passed to the shell script
#will be the height of the grid needing tiles
HEIGHT=$2;

#the third parameter passed to the shell script
#will be the height of the grid needing tiles
#can take any format imagemagick can. 
COLOR=$3;

#the tiles will be put in a directory called...
MYDIR="blank_tiles"

#the file type of the output will be... 
EXT="png"

#The zero padding in the name will be up to X characters
#zpad=2

#if the caller of this script fails to input 
#values, what should the defaults be?
if [[ -z $WIDTH ]]; then WIDTH=1204 ; fi
if [[ -z $HEIGHT ]]; then HEIGHT=864 ; fi
if [[ -z $COLOR ]]; then COLOR=white ; fi

#If the destination folder doesn't exist, make it. 
if [ ! -d ./${MYDIR} ]; then mkdir ./${MYDIR}; fi


#for the rows
for i in {0..7}; do
#do each column
    for j in {0..15}; do
        #create a column-row coordinate name with the color for each tile.
        printf -v filename "%0*dy%0*dx_%s" $zpad $i $zpad $j $COLOR;
        #add the directory and the extension (seperate from above for
        #troubleshooting reasons)
        fullname=./${MYDIR}/${filename}.${EXT};
        #do the Imagemagick!
        convert -size ${WIDTH}x${HEIGHT} xc:${COLOR} ${fullname}
    done
done