1. A method comprising: receiving an input image; creating a blurred image from the input image by averaging pixel intensities of a plurality of pixels in the input image; creating a transparency mask from the input image, the transparency mask indicating transparency values for pixel positions of the input image based on edges detected in the input image, wherein creating the transparency mask includes: detecting the edges in the input image and forming an edge map having pixels at a plurality of different values indicating the edges; blurring the edge map; and determining the transparency values based on the blurred edge map; and compositing the pixel intensities of the input image and pixel intensities of the blurred image based on the transparency values of the transparency mask to create an output image having greater blur than the input image in areas outside the detected edges.