# Area

The area of a blob is defined as the sum of the weighted pixel values for every nonzero pixel in the blob. If a hard binary threshold was applied to the image to segment it, then the area is simply the number of nonzero pixels in the blob. If grey-scale analysis is being performed, then the area is the sum of the pixel weights.

If the blob is in an image that was segmented using a hard binary threshold, the formula for the area of a blob is

If the blob is in an image that was segmented using a soft binary threshold or a pixel map, the formula for the area of a blob is

where W is the weight of the pixel at coordinate (x,y).