This “largest centered crop” is generally a safe and simple strategy. Van Tulder’s part command and MT5’s square-thumbnail-generator crop as large of a region from the source image as possible without changing the aspect ratio, and center the crop along the dimension that needs cropping. Another script by Joe Lencioni isn’t as powerful, but it does its own work using only functionality that comes with PHP–so you don’t have to have ImageMagick installed or set up additional modules. A script by Gijs van Tulder ingeniously delegates all its work to the command-line ImageMagick utility, so you can run a bewildering array of commands through a simple URL string–he even wrote a custom command, part, to do a simple crop-and-resize. With this goal in mind, I tracked down a few “smart” image resizer/croppers out there to find a starting point. What if you want a 200×50 thumbnail for a “related articles” widget for your sidebar? More generally, I want a script that will take an image, a width, and a height, and give me a thumbnail back that is exactly what a photo editor would have made in Photoshop. MT5 can make square thumbnails, but won’t make them in arbitrary dimensions.
For instance, Movable Type 5 (the CMS used by my employer) has template tags for on-the-fly generation of resized or square-cropped thumbnails. Many CMS’s also come bundled with thumbnail-generation utilities.
#WORDPRESS IMAGEMAGICK HOW TO#
If thumbnail height also needs to be 120px, then the original image should first be cropped to the 1:1 aspect ratio of the thumbnail (red box), and then resized (right).Ī Google search will turn up simple explanations on how to resize/or crop images in PHP–see “examples” at the bottom of this page, or these tutorials. You can resize it proportionally to fit the width (left), but the height will be 80px in the thumbnail. Suppose you need a 120px-wide thumbnail from a 600×400 source image. Unfortunately, a good script to do this is hard to come by, which is why I wrote Opticrop.įigure 1. If you’re doing this dozens of times a day (like our photo editor does), it would be much nicer if you could somehow use a script–you open up the URL to a script, give it the path to an image, and it serves back a cropped/resized thumbnail. You’ll need to open the source image up in Photoshop/GIMP, take your crop, and save the thumbnail for your website. However, if both dimensions are constrained, you usually have to crop the image before resizing.įor example, say your home page design uses square thumbnails, but your source images come in an odd assortment of width/height combinations.
The simplest way to make a thumbnail is to proportionally resize the original image to fit a width or height. When you link to that article (say, on your front page), it’s nice to have a thumbnail of that article’s “feature” image for your readers to click on. You’ve probably dealt with the thumbnail problem if you run a blog or website that publishes images with articles. If you just want the script, see the post on Opticrop’s usage and implementation. This post is a big-picture discussion of my method.
#WORDPRESS IMAGEMAGICK PATCH#
Unlike most cropping routines out there, Opticrop uses edge-detection to find the most “interesting” part of the image to crop, so you won’t get a useless thumbnail just because the top-left corner of your image happened to be a big patch of featureless sky. Opticrop is a PHP script I wrote to crop a thumbnail of a specific width and height from a full-sized image.
Promising options include entropy-based methods ( reddit, google search) and a commercial service ( ). Since then, similar ideas have cropped up elsewhere and are worth consulting.
#WORDPRESS IMAGEMAGICK OFFLINE#
I wrote this in 2010 and took it offline between 20, but it is now back up.
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