Wednesday, July 23, 2014

Simulate high dynamic range imaging with local contrast

As you might guess, we here are fascinated with high dynamic range images.  We may be an 8 bit per channel paint app, and there are some good things about that, but sometimes you want to squeeze as much dynamic range into a single image as you can.  Enter the local contrast filter.

No, it's not a magic bullet, but it can do some amazing things with certain kinds of images.

What it does is examine an image, and apply a dynamic range enhancement to local parts of the image.  If a part of the image has a low dynamic range, it is stretched out to the full range.

This has the effect of simulating the look of images taken with a high-dynamic-range camera.  Caution is in order, however, as this can also "flatten" out the appearance of an image that otherwise uses color and value to convey a sense of depth in an image.  It's all a matter of artistic choice.

Local contrast can also ruin an otherwise fine image, so editing may be required via selections.  It seems to have trouble with skin tones, but boy oh boy does it ever seem to work brilliantly with pictures of bicycles!

Tuesday, July 1, 2014