Create a bigger image from a set of images with the files names 00y00x (can make a subset of a bigger set image)

make_map_from_tiles.sh

#!/bin/bash
#creates a montage of images from a selection of 
#properly named files. The top left is 0, 0. The bottom
#right is presumed to be 7, 15. A subset of the map
#can be built with the correct inputs to the script. 
#REQUIRES IMAGEMAGICK


#------------------------------ INPUTS -----------------------------#
#the first parameter passed to the shell script
#will be the bigger of the two y coordinates
Y1=$1

#the second parameter passed to the shell script
#will be the smaller of the two y coordinates
Y2=$2

#the third parameter passed to the shell script
#will be the bigger of the two X coordinates
X1=$3

#the fourth parameter passed to the shell script
#will be the smaller of the two x coordinates
X2=$4

#------------------------------ CONFIG -----------------------------#
#what size should the tiles be?
WIDTH=1204
HEIGHT=862
#what is the size of the splice to the bottom?
BB=2

#how thick should the final border be around the whole image?
bordersize=100
#what color should the final border be? 
COLOR=white

#In the file name, how much zeropadding is needed?
zpad=2

#What is the name of the sub directory to save the files?
MYDIR="prepped_tiles"

#What is the file type of the images being saved?
EXT="png"

#What should the defaults be if sub coordinates are passed
#during the script call?
if [[ -z $Y1 ]]; then Y1=0 ; fi
if [[ -z $Y2 ]]; then Y2=7 ; fi
if [[ -z $X1 ]]; then X1=0 ; fi
if [[ -z $X2 ]]; then X2=15 ; fi

#------------------------------ SETUP ------------------------------#
#Correct width and height to be inclusive. 
#(0 to 7 is 8 tiles but 7-0=7)
let map_width=$X2-$X1+1
let map_height=$Y2-$Y1+1

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

#Set datetime for map file name used below. Setting
#it up here means the file name will reflect when the 
#script was run not when the file is created. 
vardate=$(date +%d\-%m\-%Y\_%H.%M.%S)

#---------- PROCESS ALL THE PNGS IN THE CURRENT DIRECTORY ----------#
# processes all pngs, assumes they are all named correctly
if ls | grep png; then for p in *.png; do
    echo "Processing $p"
    convert \( $p -gravity south -crop ${WIDTH}x${HEIGHT}+0+0 +repage \) \
        -background black -splice 0x${BB}  \
        ./${MYDIR}/${p/.png}_stats.png
done
fi

#--------- CREATE WHITE BLANK SPACES FOR MISSING TILES ONLY --------#
#for each row
for i in $(seq $Y1 $Y2); do
#do each column
    for j in $(seq $X1 $X2); do
        #what is the file prefix we will be looking for?
        printf -v fileprefix "%0*dy%0*dx" $zpad $i $zpad $j
        if [ ! -e ./${MYDIR}/${fileprefix}* ] ; then
            echo "Making white tile for $fileprefix"
            fullname=./${MYDIR}/${fileprefix}_${COLOR}.${EXT};
            convert -size ${WIDTH}x${HEIGHT} xc:${COLOR} ${fullname}
        fi  
    done
done

#-------------------------- BUILD THE MAP --------------------------#
cd ./${MYDIR}
echo "Building Map"
montage *.png -mode concatenate -tile \
    ${map_width}x${map_height} ../map_${vardate}.png

#------------------------- TRIM AND BORDER -------------------------#
cd ../
echo "Cleaning up map"
#will need to leave off trim when top corner has a tile. 
#look for white? trim only if no variables set?
convert \( map*.png -fuzz 1% -trim \) \
    -bordercolor ${COLOR} -border ${bordersize}x${bordersize} +repage \
    map_${vardate}_ready.png