Creating Cropped Thumbnails With ImageMagick

by Paul Robinson on 02.24.2009 | 6 comments

So you’ve just installed ImageMagick, but how do you make your thumbnails in it? Ahhh, a very good question my friend. Why Not Use Imagick? [...]

So you’ve just installed ImageMagick, but how do you make your thumbnails in it? Ahhh, a very good question my friend.

Why Not Use Imagick?

Well like my server, not all servers have the Imagick extention for PHP installed. Also I think (personal opinion, shock) the command line is a better way to use ImageMagick. Right let’s get to it.

How Do We Use ImageMagick From The Command Line?

Well in PHP we can use the exec() function. Some servers don’t allow you to use the command, but most, like mine, just disable the use of certain functions from that function.

Anyway here is the code I use to make square cropped thumbnails.

exec("/path/to/convert -size 120x120 'input.jpg' -thumbnail 120x120^ -gravity center -extent 120x120 'output.jpg'");

Unfortunately this will only work in versions of ImageMagick from 6.3.8-3 and upwards due to the use of -thumbnail along with the carat(^) symbol. Here is what to use if you have a lower version:

convert input.jpg -resize x120 -gravity center  -crop 120x120+0+0 +repage output.jpg

Of course for both of those commands you will need to change all the sizes to whatever you wish. Mine are 120px square as you can see. I also have my code only take in & output jpg files. For me this is fine, but if you want to have multiple formats you could just have pathinfo() run on the file name and use 120x120 '".$filename.".".$extention."' and it will convert any filetype to a jpg. Just remember that png or gif files with transparency will be saved with the transparent parts black.

That’s about it really. If you want any more info or if something I’ve wrote isn’t working let me know.