split-image.sh - Split a large image into same-size tiles

split-image.sh

#!/bin/bash -e

## split-image.sh - Split a large image into same-size tiles

## Split a large image into same-size tiles
## and optionally convert to a print-ready PDF document
##
## For example split a huge A1-size banner into 8x A4 tiles
## and create a single PDF ready for print.

## Author: Michal Ludvig <mludvig@logix.net.nz>
##         http://www.logix.cz/michal/devel
##         September 28, 2011

## ====== User configurable variables ======
## A4 @300dpi : 2480x3508
TILE_SIZE="2480x3508"
PDF_PAGE_SIZE="A4"
COLORBITS=8     # Use 8 for 256 color palette, Use 24 for Truecolor
## ====== End of user configurable variables ======

if [ "$1" = "" ]; then
        echo "Usage: $0 <input-file-name.img>"
        exit 1
fi

INFILE=$1
BNAME=$(basename ${INFILE} | sed 's/\.[^\.]*$//')

echo -en "\e[1;33m==== Processing ${INFILE}, please wait...\e[0m "
convert ${INFILE} -crop ${TILE_SIZE} +repage ${BNAME}-tile-%d.png
echo -e "\e[1;32mDone\e[0m"

ls -l ${BNAME}-tile-*.png

echo -ne '\e[1;34mConvert to PDF? [Y/n]:\e[0m '
read ANS
if [ "${ANS}" == "" -o "${ANS}" == "y" ]; then
        BNAME_PDF=${BNAME}-tiled.pdf
        echo -en "\e[1;33m==== Converting to ${BNAME_PDF}, please wait...\e[0m "
        if [ "${COLORBITS}" == 8 ]; then
                PNMFILTER='pnmquant 256'
                PNMTOTIFF_OPT=""
        else
                PNMFILTER='cat'
                PNMTOTIFF_OPT="-truecolor"
        fi
        for i in ${BNAME}-tile-*.png; do
                pngtopnm $i | ${PNMFILTER} 2>/dev/null | pnmtotiff ${PNMTOTIFF_OPT} -lzw 2>/dev/null > $(basename $i .png).tiff
        done
        tiffcp -z lzw ${BNAME}-tile-*.tiff ${BNAME}-tmp.tiff
        tiff2pdf -z -p ${PDF_PAGE_SIZE} -c $0 ${BNAME}-tmp.tiff -o ${BNAME_PDF}
        rm -f ${BNAME}-*.tiff
        echo -e "\e[1;32mDone\e[0m"
        ls -l ${BNAME_PDF}
fi

echo -ne '\e[1;34mRemove per-tile PNG files? [Y/n]:\e[0m '
read ANS
if [ "${ANS}" == "" -o "${ANS}" == "y" ]; then
        echo -en "\e[1;33m==== Removing ${BNAME}-tile-*.pdf, please wait...\e[0m "
        rm -f ${BNAME}-tile-*.png
        echo -e "\e[1;32mDone\e[0m"
fi

echo -e '\e[1;32m==== All done ====\e[0m'