Gimp: Is it possible to batch strip pic quality?

snatale1 · 07-12-2010, 07:07 PM

I'm a field tech and daily I upload between 10-30 pics to my company, the files are huge so I open them ALL w/Gimp and re-save them but change the quality slider to 20 to reduce file size. After months of this it's getting old. Is there a way to do say, an entire dir at once? I don't care if it's with Gimp or not.

kbp · 07-12-2010, 09:04 PM

Maybe ImageMagik would work, I wrote this bit of perl ( on windows ) a few years back, you should be able to modify it for linux easily.

cheers

Code:

use strict;
use warnings;

##-- vars --##
my @files;
my $dir = "c:/photos";
my ( $filesize1, $filesize2, $file, $counter, $totalFiles );
my @weekDay = qw( Sunday Monday Tuesday Wednesday Thursday Friday Saturday );
my $displayDate;

##-- subs --##
sub getDate {
	my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime time;
	$mon += 1;
	$year += 1900;
	$displayDate = "$weekDay[$wday] $mday/$mon/$year $hour:$min";

}

##-- main --##
&getDate;
$counter = 0;

opendir(PHOTOS, $dir) or die "Can't open $dir: $!";
@files = grep { /\.jpg$/ } readdir(PHOTOS);
closedir ( PHOTOS );

foreach ( @files ) {
	$file = $_;
	$filesize1 = -s "$dir/$file";
	if ( $filesize1 > 1000000 ) {
		$counter++;
		system ("mogrify -resize 640x480 $dir\\$file"); 
		$filesize2 = -s "$dir/$file";
		print "\nFile: $_\n" . "old size: $filesize1\n" . "new size: $filesize2\n\n";
	}
}

open ( LOG, ">c:/temp/reduce_log.txt" );
$totalFiles = @files;
print LOG "\n\nProcessing started: $displayDate\n";
&getDate;
print LOG "Processing completed: $displayDate\n\n";
print LOG "Files in directory: $totalFiles\n";
print LOG "Files resized: $counter\n";
close ( LOG );

John VV · 07-12-2010, 10:22 PM

are these lousy jpg's or lossless png's ( i am assuming the losley jpg)

i would first look into if you NEED the detail that is forever lost in a very compressed jpg
and if you do use *.png instead .

also imagemagick's " convert" will do a batch and so will " mogrify "
mogrify is designed for batch work.

smoker · 07-12-2010, 10:24 PM

You could try this gimp plugin. Or write your own script.