Optical member inspection apparatus, image-processing apparatus, image-processing method, and computer readable medium

An optical member inspection apparatus, comprising:

• an image pick-up device which picks up an image of an inspection target optical member, and outputs image data representing said image of the inspection target optical member;
• an extraction processor which extracts, from the image data, a portion of the image having brightness different from other portions of the image, as an extracted object;
• a graphic feature value measuring processor which measures a graphic feature value of the extracted object;
• a position measuring processor which measures a position of the extracted object in the image data;
• a normalization processor which normalizes the graphic feature value using a reference based on the position of the extracted object;
• and
• an operation processor which calculates an evaluation function based on all normalized values calculated by the normalization processor for all extracted objects extracted from the image data by the extraction processor,
• wherein said normalization processor setting the reference higher as a distance between the extracted object and the optical axis of the inspection target optical member increases,
• wherein said position measuring processor measures the position of the extracted object by discriminating a region from which the extracted object is extracted among a plurality of concentric regions centered on said optical axis, and
• wherein said normalization processor sets the reference based on the region discriminated by the position measuring processor.

An image-processing apparatus, comprising:

• an extraction processor which extracts, from an image data representing an inspection target optical member, a portion of said image data indicating an extracted object of said optical member having a brightness different from surrounding areas of said optical member;
• a graphic feature value measuring processor which measures a graphic feature value of the extracted object;
• a position measuring processor which measures a position of the extracted object in the image data relative to an optical axis of said inspection target optical member;
• a normalization processor which calculates a normalized value of the extracted object, by normalizing the graphic feature value using a reference based on the position measured by the position measuring processor such that the graphic feature value of the extracted object is weighted with a distance between the position of the extracted object and the optical axis of said inspection target optical member so that the graphic feature value becomes heavier as the distance decreases;
• and
• an operation processor which calculates an evaluation function based on all normalized values calculated by the normalization processor with respect to all extracted objects which are extracted from said image data by the extraction processor.

An image-processing method, comprising:

• extracting, from image data representing an inspection target optical member, an extracted object comprising a portion of said optical member having a brightness different from a surrounding area of said optical member in the image data;
• measuring a graphic feature value of the extracted object;
• measuring a position of the extracted object in the image data relative to an optical axis of the inspection target optical member;
• calculating a normalized value of the extracted object, by normalizing the graphic feature value using a reference in accordance with the position of the extracted object such that the graphic feature value of the extracted object is weighted with a distance between the position of the extracted object and the optical axis of the inspection target optical member so that the graphic feature value becomes heavier as the distance decreases;
• and
• calculating an evaluation function based on all normalized values with respect to all extracted objects which are extracted from said image data.

An image-processing method, comprising:

• extracting, from image data representing an inspection target optical member, an extracted object comprising a portion of an optical member having a brightness different from a surrounding area of the optical member in the image data;
• measuring a graphic feature value of the extracted object;
• measuring a position of the extracted object in the image data;
• calculating a normalized value of the extracted object, by normalizing the graphic feature value using a reference in accordance with the position of the extracted object, the normalized value being calculated by dividing the graphic feature value of the extracted object by the reference which increases as a distance between the extracted object and the optical axis inspection target optical member increases;
• and
• calculating an evaluation function based on all normalized values with respect to all extracted objects which are extracted from the image data, wherein measuring a position of the extracted object discriminates a region, among a plurality of concentric regions within the image of the inspection target optical member about the optical axis of the inspection target optical member, and from which the extracted object is extracted;
• and
• wherein calculating a normalized value divides the graphic feature value of the extracted object by a reference value corresponding to the discriminated region.

A computer readable media storing a program for causing a computer to perform a method, comprising:

• extracting, from image data representing an inspection target optical member, an extricated object portion of said optical member having brightness different from a surrounding area of said optical member;
• measuring a graphic feature value of the extracted object relative to an optical axis of said inspection target optical member;
• measuring a position of the extracted object in the image data;
• calculating a normalized value of the extracted object, by normalizing the graphic feature value using a reference in accordance with the position of the extracted object such that the graphic feature value of the extracted object is weighted with a distance between the position of the extracted object and the optical axis of said inspection target optical member so that the graphic feature value becomes heavier as the distance decreases;
• and
• calculating an evaluation function based on all normalized values with respect to all extracted object which are extracted from same image data.