Comments on: Howto: Linux Creating a Image Thumbnails from shell prompt

By: lee

lee — Fri, 15 Apr 2011 14:16:45 +0000

You can get tiny JPEGs or PNGs out of large files, using IM, if you RTFM rather than blast it — check out colour profiles, the ‘thumbnail’ command option, colour spaces….

By: marc41

marc41 — Thu, 26 Mar 2009 14:58:33 +0000

Here is a script that does this and MUCH MORE!

– Enjoy!

By: Flor

Flor — Thu, 06 Sep 2007 02:30:02 +0000

I have a suggestion to execute it in bash:

ls *.png | xargs -I {} convert -thumbnail 200 {} thumb.{}

By: Steve Lajoie

Steve Lajoie — Sat, 11 Aug 2007 00:36:36 +0000

The latests version of convert doesn’t seem to have the -thumbnail option.

My version of the shell script works likes this:

for image in $@
do
echo “found file $image and making thumb”
convert $image -resize 100x thumb-$image
done

So if you have a image named “image001.jpg” you get a thumbnail named “thumb-image001.jpg”.

By: Felix

Felix — Fri, 13 Jul 2007 20:27:22 +0000

The script is buggy with my versions of djpeg (6b), pnmscale (netpbm 10.0) and cjpeg (6b). Not processing the thumbs that are already there, it should read:

for i in [^TN_]*.jpg
do
djpeg $i | pnmscale -xysize 48 38 | cjpeg -optimize -progressiv -quality 75 > TN_$i;
echo $i thumbnails created;
done

By: Felix

Felix — Fri, 13 Jul 2007 19:10:33 +0000

Addition to Tim’s script:
If you do not want to re-thumb the thumbnails which would result in things like TN_TN_image.jpg, simply use this first line:

for i in [^TN_]*.jpg

By: michuk

michuk — Fri, 11 May 2007 08:53:12 +0000

Another useful article on the subject: http://polishlinux.org/apps/graphics/enchanting-pictures-with-imagemagick/
(massive resizing, adding text or frames to images, etc, all with ImageMagick)

By: Alejandro G. Bedoya

Alejandro G. Bedoya — Tue, 14 Nov 2006 06:50:43 +0000

find . -name \*.jpg -exec convert {} -resize 25% th_{} \;

By: LinuxTitli

LinuxTitli — Tue, 06 Dec 2005 13:20:00 +0000

You are right tim. But main problem is we got all images in .png format and not .jpg format. However if it is in jpg format your script will save disk space and it is really optimized solution. Thanks for sharing with us, appreciate your post.

By: Tim

Tim — Tue, 06 Dec 2005 05:55:00 +0000

Two comments here:

a) for batch purposes, you can either use a shell script or even the mogrify command (part of imagemagick):

bash$ for i in *.jpg
do
convert -scale ’48×38′ $i TN_$i
echo $i processed
done

mogrify -format jpg -quality ’95%’ *.tiff (bulk-conversion)

b) For thumbnails, you quite often don’t want to use imagemagick or convert or whatever; for my normal size (48×38), it creates a whopping huge 50K jpg when there are other ways of getting them much much smaller:

bash$ for i in *.jpg
do
djpeg $i | pnmscale -xysize 48 38 | cjpeg -opti -progr -qual ’75%’ > TN_$i
echo $i processed
done

This keeps the average image-size down to about 1K – rather more suited to a page of thumbnails!

HTH

By: LinuxTitli

LinuxTitli — Mon, 05 Dec 2005 11:33:00 +0000

Well I have an agreement with my employer, the script is part of in house build software system, I wrote basic script and later they modified it for web based software, so I can’t put it on line until and unless they give me permission (copyright sucks)

By: riscphree

riscphree — Mon, 05 Dec 2005 03:16:00 +0000

Wow, that is awesome!

But why cant you put the perl script here?