Patent ID: 8571279

Claim:
A spot quantification apparatus comprising: an image input unit which receives an image including a spot; a filtering unit which filters the image input through said image input unit a plurality of times while changing a parameter of a kernel within a predetermined range; and a spot quantification unit which quantifies a feature of the spot based on a luminance distribution in each image which has been filtered a plurality of times by said filtering unit, wherein: said filtering unit changes a bandwidth of the kernel within a predetermined range to perform the filtering a plurality of times; said spot quantification unit finds peak values of a normalized luminance distribution in each image which has been filtered a plurality of times by said filtering unit, finds a maximum value in the peak values, and quantifies the bandwidth of the kernel used for an image in which the maximum value has been found; at least one of the image input unit, the filtering unit and the spot quantification unit is implemented by a processor; said kernel is a concentric kernel defined by: K ⁡ ( x ) = 1 π ⁢ ⁢ r 1 2 ⁢ I {  x  ≤ r 1 } - 1 π ⁡ ( r 2 2 - r 1 2 ) ⁢ I { r 1 ≤  x  ≤ r 2 } , where K(x) is a filter function, x is an input value for luminance, r 1 is a radius of an internally concentric circle of the kernel, and r 2 is a radius of an external concentric circle of the kernel; and said filtering unit changes a radius of an internal circle of the kernel within a predetermined range to perform the filtering a plurality of times.