bash ImageMagick Image Slicer

This is a bash script which accepts an image file, determines the width and height, and creates five vertical segments. It can be used to create a ‘puzzle’, tiles, CAPTCHA sequences and other interesting visual effects.

#!/bin/bash
if [ "$#" -le 2 ]; then
       echo "usage: $0 <base directory> <image file> <segments> [<imagemagick directory>]"
else
BASE_DIR="$1"
ORIGINAL_IMAGE="$2"
SEGMENTS="$3"
if [ "$#" -ge 4 ]; then
        IMAGEMAGICK_DIR="$4"
else
        IMAGEMAGICK_DIR=''
fi
RESIZED_IMAGE="image.jpg"
IMAGE_WIDTH=300
"$IMAGEMAGICK_DIR"convert "$BASE_DIR$ORIGINAL_IMAGE" -resize "$IMAGE_WIDTH"x +repage "$BASE_DIR$RESIZED_IMAGE"
IMAGE_DIMENSIONS=`"$IMAGEMAGICK_DIR"identify "$BASE_DIR$RESIZED_IMAGE" | cut -f 3 -d ' '`
SEGMENT_WIDTH=$((`echo "$IMAGE_DIMENSIONS" | cut -f 1 -d 'x'`/$SEGMENTS))
SEGMENT_HEIGHT=`echo "$IMAGE_DIMENSIONS" | cut -f 2 -d 'x'`
echo '<?php'
echo define\(\'SEGMENTS\',"$SEGMENTS"\)\;
echo define\(\'IMAGE_WIDTH\',"$IMAGE_WIDTH"\)\;
echo define\(\'IMAGE_HEIGHT\',"$SEGMENT_HEIGHT"\)\;
echo define\(\'SEGMENT_WIDTH\',"$SEGMENT_WIDTH"\)\;
echo define\(\'SEGMENT_HEIGHT\',"$SEGMENT_HEIGHT"\)\;
for A in `seq 0 $(($SEGMENTS-1))`
do
       SEGMENT_OFFSET=$(($SEGMENT_WIDTH * $A))
       "$IMAGEMAGICK_DIR"convert "$BASE_DIR$RESIZED_IMAGE" -crop "$SEGMENT_WIDTH"x"$SEGMENT_HEIGHT+$SEGMENT_OFFSET+0" "$BASE_DIR"segments/"$A".jpg
done
"$IMAGEMAGICK_DIR"convert "$BASE_DIR$RESIZED_IMAGE" -colorspace gray -level 0,80%,4.0 "$BASE_DIR"target.jpg
fi

The last convert command creates a a faded version of the image.

Further customization could include segmentation on a different axis, different image file formats, etc.