smallermaker-comparisons.sh

#!/bin/bash

FROM=gif
TO=png
CRUSHED=opt.png
IMGPATH=$1
IMGPATH=${IMGPATH:=.}
current=1

header() {
    echo "#/#: orginal file : new file : space saved\n"
    echo $count "total files to process."
}

report() {
    printf " : %q : %q bytes\n" $1 $2
}

shrink_png() {
    local file=$1
    PNGFILE=$file
    PNGCRUSHED=${file%%$TO}$CRUSHED
    # Step 1, create backup of original png
    cp $PNGFILE $PNGFILE.bak;
    
    printf "Orig - %q\noptipng - " $(stat -f%z $PNGFILE)

    # Step 2, optipng the original png, and report its size
    optipng -o7 -q $PNGFILE;
    printf "%q\nadvpng - " $(stat -f%z $PNGFILE)
    
    # Step 3, copy original png back, advpng it, and report size
    cp $PNGFILE.bak $PNGFILE;
    advpng -z -4 -q $PNGFILE;
    printf "%q\npngout - " $(stat -f%z $PNGFILE)
    
    # Step 4, copy original png back, pngout it, and report size
    cp $PNGFILE.bak $PNGFILE;
    pngout -q $PNGFILE;
    printf "%q\noptipng+advpng - " $(stat -f%z $PNGFILE)
    
    # Step 5, optipng, then advpng
    cp $PNGFILE.bak $PNGFILE;
    optipng -o7 -q $PNGFILE;
    advpng -z -4 -q $PNGFILE;
    printf "%q\noptipng+advpng+pngout - " $(stat -f%z $PNGFILE)
    
    # Step 6, optipng, then advpng, then pngout
    pngout -q $PNGFILE;
    printf "%q\noptipng+pngout+advpng - " $(stat -f%z $PNGFILE)
    
    # Step 7, optipng, then pngout, then advpng
    cp $PNGFILE.bak $PNGFILE;
    optipng -o7 -q $PNGFILE;
    pngout -q $PNGFILE;
    advpng -z -4 -q $PNGFILE;
    printf "%q\n" $(stat -f%z $PNGFILE)
    
    
    rm $PNGFILE.bak;
    
    #rm $PNGFILE;
    #optipng -o7 -q $PNGCRUSHED;
    #advpng -z -4 -q $PNGCRUSHED;
    #pngout -q $PNGCRUSHED;
    #mv $PNGCRUSHED $PNGFILE;
}
shrink() {
    local file=$1
    #printf "%q/%q: %q" $current $count $file 
    FILETYPE=`file $file | awk '{print $2}' | tr '[A-Z]' '[a-z]'`;
        if [ $FILETYPE == $FROM ] #input is a gif
        then
            local start_size=$(stat -f%z $file)
            local png_file=${file%%$FROM}$TO
            pngout -q $file;
            shrink_png $png_file
            local end_size=$(stat -f%z $png_file)
            if [ $start_size -gt $end_size ] # PNG is smaller, use png not gif
            then
                rm $file;
                #report $PNGFILE $(($start_size - $end_size))
            else # GIF is smaller, so delete the generated png
                rm $png_file
                #report $file 0
            fi
        elif [ $FILETYPE == $TO ] #input is a png
        then
            local start_size=$(stat -f%z $file)
            shrink_png $file
            local end_size=$(stat -f%z $file)
            #report $PNGFILE $(($start_size - $end_size))
        fi
    let current=current+1
}

if [ -f $IMGPATH ]; then
    count=1
    header
    shrink $IMGPATH
else
    files=$(find $IMGPATH -regex ".*.[png]") 
    count=$(find $IMGPATH -regex ".*.[png]" | wc -l)
    header
    for file in $files; do
        shrink $file
    done
fi