Patent ID: 6031931
Filing Date: 2000-02-29
Classification: G06T

Abstract:
Apparatus for determining at least one edge of a device having a plurality of openings with respective edges, said apparatus, comprising:imaging means for generating an image signal of said device, said image signal representing maximum and minimum light intensity values of a plurality of pixels;processing means for receiving and processing said image signal to estimate a linear relationship derived from the light intensity values of a predetermined number of said pixels, said linear relationship representing a portion of a line defined by the portion parameters; anddetermining means for determining whether said linear relationship includes at least one light intensity value corresponding to an edge, said determining means including a memory for storing a plurality of preset edge offset values each corresponding to a distance between a respective pixel and a respective edge and for storing at least one set of predetermined line portion parameters, said memory receiving said line portion parameters as an address and outputting one edge of offset value corresponding to an estimated distance between one pixel and the respective edge in response to said address, said determining means being operable to estimate a location on said portion of said line having an intensity level approximately equal to a value halfway between the maximum and minimum light intensity levels, said location corresponding to a respective edge, said determining means further including means for comparing said line portion parameters to said at least one set of stored predetermined line portion parameters, and, wherein said determining means is operable to provide the edge offset value corresponding to an estimated distance between one pixel and the respective edge corresponding to said location as an output signal if said line portion parameters are equal to a set of said stored predetermined line portion parameters.