vlt.image.circular_filter

  vlt.image.circular_filter - applies a circular filter around a pixel that blurs.

  IM_OUT = vlt.image.circular_filter(IM, USEGAUSSIAN, RADIUS, FILTERSIZE)

  Applies a circular convolutional filter to an image IM. If USEGAUSSIAN is 1,
  then the filter is a gaussian with sigma equal to RADIUS. If USEGAUSSIAN is 0,
  then the filter is a circle with RADIUS. The filter is normalized to sum to 1.
  FILTERSIZE is the size of the filter; it is recommended that FILTERSIZE be a few times
  larger than RADIUS for Gaussian filters and a little more than twice the RADIUS for
  circular filters.

  The image that is returned will be a double.

  Written by Sam Greene and Steve.

  Example:
     im = imread('coins.png');
     im_out = vlt.image.circular_filter(im,1,10,100);
     vlt.plot.imagedisplay(im);
     vlt.plot.imagedisplay(im_out);