Saturday, July 9, 2011

Despeckle filter

One approach to reduce CCD noise on an image is using a despeckle filter, then sharpening the image to offset the blurring effect of the despeckle filter. Implementation of the particular sharpening method is in progress, so far I have the Sobel edge magnitude filter mentioned in the last post.

For the despeckle part, I pushed a GStreamer port of the GIMP Despeckle filter to github. It is basically an adjustable region size median filter that can optionally adjust filtering region size based on the histogram of the region. It can also optionally operate in a recursive mode, in which filtered pixel data is also written back to the source buffer, producing a different, and stronger, effect. Region size, bright and dark thresholds, recursivity, and adaptivity can be adjusted via element properties. The plugin can be installed the usual way. The name of the element will be "gimpdespeckle".

No comments:

Post a Comment