Methods for defining mask of substantially color-homogeneous regions of digitized picture stock

A method for defining a mask of a substantially color-homogeneous region of a frame of digitized picture stock, the region comprising a plurality of points each having a luminance value, the method comprising the steps of:

• selecting a seed point from the plurality of points of the region of the frame;
• generating a test area around the seed point, the test area comprising a plurality of points including a point having a highest luminance value and a point having a lowest luminance value;
• determining a range of luminance values based upon the luminance values of the plurality of points of the test area, wherein said range includes an upper boundary value defined by the highest luminance value and a lower boundary value defined by the lowest luminance value;
• adjusting at least one of the boundary values;
• identifying points of the region which have luminance values within the range of luminance values by comparing the luminance value of each point of the region outside of the test area with the boundary values of the range of luminance values;
• and
• defining a mask comprised of the identified points.