This script parses an image that has a legend in the top left hand corner. If an area of the corner is green then the file gets copied to a new directory with the appropriate coordinates.

rename_with_map_prefix.sh

#!/bin/bash

#Reduce time by running process for just the part of the
#grid actually represented
Y1=$1
Y2=$2
X1=$3
X2=$4

#used in prefix generation
ZPAD=2

#folder files saved into
MYDIR="named_tiles"

#About the image being processed and where to look
#on the legend for the location information.
#How far from the top left corner
XOFFSET=193
YOFFSET=90
#How big of an area am I searching from that offset?
let KEYWIDTH=497-$XOFFSET
let KEYHEIGHT=210-$YOFFSET
#How many possible tiles represented in that region?
NUM_X_POS=16 #how many tiles wide?
NUM_Y_POS=8  #how many tiles tall?
#How big will each tiles representative area be? 
let XMULTIPLIER=${KEYWIDTH}/${NUM_X_POS}
let YMULTIPLIER=${KEYHEIGHT}/${NUM_Y_POS}
#Look in the middle of that area. 
let XOFFSET=XOFFSET+XMULTIPLIER/2
let YOFFSET=YOFFSET+YMULTIPLIER/2

#What color on the legend indicates where I am. 
#This result will be based on the formating used below.
TRUECOLOR="136,216,0"

#Some variables needed to generate the route from I took if all
#my origin, which is not the top left.
#Will only work if the files are from the same day. 
NL=$'\n'
MYROUTE="MY ROUTE:$NL"
ROUTEX=7 #if not far left tile, 0, then where?
ROUTEY=7 #if not top tile, 0, then where? 

#The defaults if no variables are passed into the script. 
if [[ -z $Y1 ]]; then Y1=0 ; fi
if [[ -z $Y2 ]]; then let Y2=${NUM_Y_POS}-1 ; fi
if [[ -z $X1 ]]; then X1=0 ; fi
if [[ -z $X2 ]]; then let X2=${NUM_X_POS}-1 ; fi

if [ ! -d ./${MYDIR} ]; then mkdir ./${MYDIR}; fi

#--------------  START LOOP ----------------------#
# If there are PNG files... get them. 
if ls | grep png; then for p in *.png; do
    echo "Processing $p"
    found=0
    
    #Begin row-col scan with first row. 
    for i in $(seq $Y1 $Y2); do
        let YCORD=${YOFFSET}+${i}*${YMULTIPLIER}
        
        #FOR ROUTE TEXT
        let YLOC=ROUTEY-${i} 
        
        #Begin col scan with first col
        for j in $(seq $X1 $X2); do
            let XCORD=${XOFFSET}+${j}*${XMULTIPLIER}
            
            #FOR ROUTE TEXT
            let XLOC=ROUTEX-${j}
            if [ "$XLOC" -ge 0 ]
                then XDESC="E"
                else XDESC="W"
            fi
            XLOC=${XLOC#-}
            
            #The format of this line should match pattern of TRUECOLOR. 
            mycolor=$(convert $p[1x1+${XCORD}+${YCORD}] -format "%[fx:floor(255*u.r)],%[fx:floor(255*u.g)],%[fx:floor(255*u.b)]" info:-)
            #echo "I look $mycolor at $XCORD, $YCORD"
            
            if [ "$mycolor" == "$TRUECOLOR" ]; then
                found=1
                
                #FOR ROUTE TEXT
                printf -v location "%0*dN, %0*d%s" $ZPAD $YLOC $ZPAD $XLOC $XDESC
                MYROUTE="${MYROUTE}${location}$NL"
                #echo "I am at $location"
                
                #FILE RENAME AND MOVE
                printf -v fileprefix "%0*dy%0*dx" $ZPAD $i $ZPAD $j
                #copy the file while preserving timestamps
                cp -p $p ./${MYDIR}/${fileprefix}_${p}
                #echo "I am at $filename"
                                
                break 2
            fi
        done
    done
    #If I don't belong anywhere... Death images will trigger this.  
    if [ "$found" -lt 1 ]
    then
        cp -p $p ./${MYDIR}/HELP_${p}
    fi 
done
fi
#------------------ END LOOP ------------------------#

#Save the route to file. 
#Will only work if complete sequence runs. That is a 
#feature for now. 
echo "$MYROUTE" > route.txt