Today I was reading trough the ImageMagick ChangeLog and noticed an interesting entry. “Add support for liquid rescaling”. I rushed to check the MagickWand API docs and there it was: MagickLiquidRescaleImage! After about ten minutes of hacking the Imagick support was done. Needless to say; I was excited :)

For those who don’t know what seam carving is check the demo here. More detailed information about the algorithm can be found here: “Seam Carving for Content-Aware Image Resizing” by Shai Avidan and Ariel Shamir

To use this functionality you need to install at least ImageMagick 6.3.8-2 and liblqr. Remember to pass –with-lqr to ImageMagick configuration line. You can get liblqr here: http://liblqr.wikidot.com/. The Imagick side of the functionality should appear in the CVS today if everything goes as planned.

Here is a really simple example just to illustrate the results of the operation. The parameters might be far from optimal (didn’t do much testing yet). The original dimensions of image are 500×375 and the resulting size is 500×200.

Update: the functionality is pending until license issues are solved.

php
< view plain text >
  1. <?php
  2.  
  3. /* Create new object */
  4. $im = new Imagick( 'test.jpg' );
  5.  
  6. /* Scale down */
  7. $im->liquidRescaleImage( 500, 200, 3, 25 );
  8.  
  9. /* Display */
  10. header( 'Content-Type: image/jpg' );
  11. echo $im;
  12.  
  13. ?>

The original image by flickr/jennconspiracy

result

And the result:

result

Update. On kenrick’s request here is an image which is scaled down to 300×300

result2