Abstract: Methods and apparatus for detecting the presence and location of punch holes in a scanned image are described. The punch hole detection methods and apparatus rely at least in some embodiments on whether a portion of the scanned image, referred to as a component, corresponds to a punch hole by comparing one or more characteristics of the component such as its circularity, aspect ratio, black to white pixel ratio, density, height and/or width to one or more thresholds before making a decision as to whether or not the component is a punch hole. In some embodiments the components which pass component-level checks are grouped and one or more group-level checks are performed on the components to determine if the components are punch holes. Once a punch hole is detected, in some embodiments, the image is processed to remove the detected punch hole.

Abstract: Methods and apparatus for detecting the presence and location of punch holes in a scanned image are described. The punch hole detection methods and apparatus rely at least in some embodiments on whether a portion of the scanned image, referred to as a component, corresponds to a punch hole by comparing one or more characteristics of the component such as its circularity, aspect ratio, black to white pixel ratio, density, height and/or width to one or more thresholds before making a decision as to whether or not the component is a punch hole. In some embodiments the components which pass component-level checks are grouped and one or more group-level checks are performed on the components to determine if the components are punch holes. Once a punch hole is detected, in some embodiments, the image is processed to remove the detected punch hole.