Resizing to 100 x 100 with ImageMagick

ewingtux · 11-27-2007, 11:34 AM

Hi,

I have just grabbed a load of images to a folder with wget. However they are all different sizes and over 100 pixels wide and I need to resize each of them so they fit into a 100 x 100 pixel size.

Does anyone know the command I can used in bash to do this? (perhaps to reduce quality by 20% also ie. 80% of original quality)

Thanks in advance
Ed

matthewg42 · 11-27-2007, 11:59 AM

To resize a bunch of .jpg files:

Code:

mogrify -resize 100x100 *.jpg

You can specify a quality with a -quality option, which you might as well do at the same time. The files will be re-encoded as part of the resize, so just choose a quality level you like. e.g.

Code:

mogrify -quality 50 -resize 100x100 *.jpg

colucix · 11-27-2007, 12:03 PM

To resize exactly at 100x100 pixels

Code:

convert <input-image> -resize 100x100! <output-image>

but if you want a maximum size of 100 pixels and mantain the aspect ratio, take out the exclamation mark. A list of options to the convert command is available on the ImageMagick website, here.

Edit: uh... I did not know mogrify... sure better!

jlinkels · 11-27-2007, 04:53 PM

Code:

convert -thumbnail width
convert -thumbnail widthxheight{%} {@} {!} {<} {>}

create a thumbnail of the image.

This is exactly like -resize, except that any image profiles present are also removed as they are of little importance to small image thumbnails.

jlinkels