Patent ID: 7110591

Claim:
A method for detecting a marker in an image, comprising the steps of: selecting one of a first marker recognition process based on a normalized correlation and a second marker recognition process based on gray value histograms; extracting image features associated with an input image of a ROI (region of interest); and comparing the extracted image features with a trained model associated with the selected recognition process to determine if a marker is present in the input image, wherein if the first marker recognition process is selected, the trained model comprises at least one template image for a first template class and at least one template image for a second template class, wherein the at least one template image for the first template class is trained from one or more images of the ROI having a maker, and wherein the at least one template image for the second template class is trained from one or more images of the ROI not having the marker, and wherein the step of comparing comprises the steps of: normalizing the template images and input image with respect to brightness; computing a correlation between the input image and each normalized template image; and determining if a marker is present in the input image based on the computed correlations.