#
#   Author: Heir!1APPARENTs
#
#   This script is expecting to run in GNU BASH version 3.2 or later, and is also
#   dependant on the 'convert' program from the Imagemagick package.
#
#   You must make sure 'convert' is in $PATH, and that you run this script in the
#   same directory as the image you plan to use.
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
 
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
reSizeAll() {
 
xres=$1
yres=$2
renmask=$3
#Making the variable names friendly.
 
echo "Re-sizing ... This could take a long time.."
convert $renmask* -resize $(($xres))x$(($yres))! "final_"$renmask
#Re-sizing all images in $PWD that begin with $renmask to the dimensions of the original image.
echo "Done re-sizing, removing all old images.. last chance to pull the plug on it ctrl c .."
sleep 5
rm $renmask*
#Removing the old images.
}
 
reSize() {
 
i=0
o=0
count=0
#Integers to be incremented, helps to get around nesting while loops, which BASH doesn't like.
 
max=$1
xres=$2
yres=$3
picname=$4
renmask=$5
count2=$(( ($max*$max) + 1))
#Re-writing the passed variables to more friendly names, making a separate counter for opposite operation images.
 
while [ $count -le $(($max*$max)) ]
 
do
 
        if [ $i = $max ]; then
                o=$(($o+1))
                i=0;
        fi;
       
        convert $picname -resize $(($xres - $i))x$(($yres - $o))! $renmask$count
        convert $picname -resize $(($xres + $i))x$(($yres + $o))! $renmask$count2
       
        i=$(($i+1))
        count=$(($count+1));
        count2=$(($count2+1));
 
done
#Creates new images that are different by up to $max in the x and y, naming them with their iteration number and mask.
}
 
echo "This script will make very similar images, it will do so by re-sizing the original by pixels at a time, then re-sizing them back to the original dimensions. This relies on the data lost / created in the initial re-sizes.
This will create MANY new images, so you may want to run it in a new directory (folder)."
echo ""
echo "Name of the picture, extension included"
read picname
echo "Alright, now the max number of pixels to shrink / expand by"
read max
echo "Now the  X  resolution"
read xres
echo "Now the  Y  resolution"
read yres
echo "Now the renaming mask, so I don't overwrite other pictures you may have etc.. make sure it's unique in this directory."
read renmask
 
echo "This could take some time to finish..."
 
reSize $max $xres $yres $picname $renmask
 
echo ""
echo "Should be done making the new images.. Just have to re-size them..."
echo ""
echo ""
echo "If you made over 400 images, this could get messy, as 'convert' buffers, meaning it will chew up a bunch of system memory. If you don't have enough memory, your computer may slow, or just eat it.."
echo ""
echo "This will re-size (making a copy of) every image in the directory who's name begins with your chosen re-naming mask, then delete all the old ones with said mask."
echo ""
echo "Are you sure you want to continue? y / n"
read ans
 
if [ "$ans" = "y" ]; then
        reSizeAll $xres $yres $renmask
       
elif [ "$ans" = "n" ]; then
        echo "exiting.."
        exit
else
        echo "invalid option, should be either 'y' or 'n', exiting.."  
        exit
fi;
 
echo "All done.."
exit