Smart Thumbnail Cropping

Jan, 2013

Scaling an image down to a thumbnail size is a common practice when hosting it on websites to reduce page load time and save bandwidth and so on.. But very little has been done in optimization of those thumbnails from a human view-ability point of view. Human view-ability, what? Take a large image where background covers the major part of the image and shrink it down to a thumbnail size (say 192 px) and notice that the details of the image is subdued by the background.

To solve this problem of smart cropping, I am using a variation of descriptors and image processing tricks to extract only the most feature rich part of the image and preserve the aspect ratio while cropping the image. Following are the test results of algorithm used:

Sample 1

Original Thumbnail	Feature Extraction	Cropped Thumbnail
Sample 2

Original Thumbnail	Feature Extraction	Cropped Thumbnail
Sample 3

Original Thumbnail	Feature Extraction	Cropped Thumbnail

So what's in the pipeline:

Open source the image processing code
Build a http handler (ASP.NET http handler) for dynamic cropping

Thoughts?