Store encrypted file as PNG (2017/01/15)

#!/bin/bash
#------------------------------------------------------------
# To encrypt and store a file as a lossless PNG
#
# $ cat fileto.store | ./tocolor.sh imagefilename.png columnsize
#
# You will be prompted for your encryption key/passphrase
#
# You can pipe pretty much anything into it
# so output from tar, echo, etc will all work too.
#------------------------------------------------------------

#-----------------------------------------
# Initialize some counters
#-----------------------------------------
counter=0
rowcounter=0
colorcounter=0

#-----------------------------------------
# Initialize color arrays
# and cache some math to make things
# run faster.
#-----------------------------------------
declare -A colorarray
declare -A fabcolors
alphaarray=(A B C D E F G H I J K L M N O P Q R S T U V W X Y Z)

# Blues and purples theme
precolorarray=(000080 00008B 0000CD 0000FF 191970 1E90FF 4169E1 483D8B 4B0081 4B0182 6A5ACD 7B68EE 800080 8A2BE1 8A2CE2 8B008B 9370DB 9400D3 9932CC BA55D3 D8BFD8 DA70D6 DDA0DD E6E6FA EE82EE FF11FF FF00FF)

# Or dark greys to look black instead
# precolorarray=(000001 000002 000003 000004 000005 000006 000007 000008 000009 000010 000011 000012 000013 000014 000015 000016 000017 000018 000019 000020 000021 000022 000023 000024 000025 000026)

for oneletter in "${alphaarray[@]}"
do
    # Fill the colorarray
    colorarray["$oneletter"]="${precolorarray[$colorcounter]}"
    let colorcounter+=1

    # Fill the fabcolors array
    hexinput=${colorarray[$oneletter]}
    a=`echo $hexinput | cut -c-2`
    b=`echo $hexinput | cut -c3-4`
    c=`echo $hexinput | cut -c5-6`
    r=`echo "ibase=16; $a" | bc`
    g=`echo "ibase=16; $b" | bc`
    b=`echo "ibase=16; $c" | bc`
    fabcolors[$oneletter]="(  $r,  $g,  $b)  #$hexinput  srgb($r,$g,$b)\n"

done

#-----------------------------------------
# How wide did we set the image?
# or just default to 500 pixels wide
#-----------------------------------------

if [ ! -n "$2" ]; then
    echo "Setting Column Size to 500"
    columnsize=500
else
    echo "Setting Column Size to $2"
    columnsize=$2
fi
collimit=$(($columnsize-1))

#-----------------------------------------
# start encrypting, encoding, and
# building the PNG.
#-----------------------------------------
ccrypt -e | codegroup | tr '\n' ' '| (
    # while loop
    while IFS= read -r -n1 theletter
    do
        if [ $counter -gt $collimit ]; then
            counter=0
            let rowcounter+=1
        fi
        if [[ $theletter = *[!\ ]* ]]; then
            echo -e -n "$counter,$rowcounter: ${fabcolors[$theletter]}"
            let counter+=1
        fi
    done
    let rowcounter+=1
    echo " ImageMagick pixel enumeration: $columnsize,$rowcounter,255,srgb"
) |sed '1h;1d;$!H;$!d;G' | convert -monitor txt: "$1"