If you are having trouble getting some of your style changes to apply make sure you remembered generate the scaffold without stylesheets in the previous episode.
In hindsight this was obvious, but dont apply any css width or height modifiers to the image the user is cropping. If you do this imagemagick will fail with "geometry does not contain image" since the coordinates you are giving it are not of the true image.
If you are having trouble getting some of your style changes to apply make sure you remembered generate the scaffold without stylesheets in the previous episode.
In hindsight this was obvious, but dont apply any css width or height modifiers to the image the user is cropping. If you do this imagemagick will fail with "geometry does not contain image" since the coordinates you are giving it are not of the true image.