Variable blend width compositing

An apparatus for producing a rendered image with a blurred background from an initial image and a depth map of the image, said depth map identifying at least one foreground region and at least one background region of the image, said apparatus comprising:

• a processor;
• and
• a memory storing a non-transitory computer executable program for directing the processor to perform a method comprising the steps of:
• determining an edge visibility measure for at least one edge in the depth map by comparing a parameter value associated with a pixel in the foreground region near the edge with a parameter value associated with another pixel in the background region near the edge;
• applying a spatially variable blur to the depth map to produce a compositing matte, wherein a size of a blur kernel used to form the spatially variable blur is dependent on the determined edge visibility measure;
• applying a blur to image data in at least one background region of the depth map to form normalized blurred background image data;
• and
• compositing the blurred background image data with the initial image in a weighted average defined by the compositing matte to produce the rendered image with the blurred background.

A computer readable non-transitory storage medium storing a computer executable program for directing a processor to execute a method of producing a rendered image with a blurred background from an initial image and a depth map of the image, said depth map identifying at least one foreground region and at least one background region of the image, said method comprising the steps of:

• determining an edge visibility measure for at least one edge in the depth map by comparing a parameter value associated with a pixel in the foreground region near the edge with a parameter value associated with another pixel in the background region near the edge;
• applying a spatially variable blur to the depth map to produce a compositing matte, wherein a size of a blur kernel used to form the spatially variable blur is dependent on the determined edge visibility measure;
• applying a blur to image data in at least one background region of the depth map to form normalized blurred background image data;
• and
• compositing the blurred background image data with the initial image in a weighted average defined by the compositing matte to produce the rendered image with the blurred background.