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...nts in the 2D image. Extracting these from an image is less of a problem e.g. one can just use an edge detector. Huttenlocher et al. developed methods in this category based on the Hausdorff distance =-=[22]-=-; this can be extended to deal with partial matching and clutter. A drawback for our purposes is that the method does not return correspondences. Methods based on Distance Transforms, such as [15], ar...

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...YES color space followed by smoothing in order to yield contiguous regions. Next, an elliptical face template is used to determine the similarity of the skin color regions based on Hausdorff distance =-=[65]-=-. Finally, the eye centers are localized using several cost functions which are designed to take advantage of the inherent symmetries associated with face and eye locations. The tip of the nose and th...

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...which operate directly on images rather than first extracting discrete features. These include both appearance-based methods (e.g., [40] and [30]) and templatebased methods such as Hausdorff matching =-=[22]-=-. Such approaches treat images as the entities to be recognized, rather than having more abstract models based on features or other primitives. One or more training images of an object are used to for...

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...correlation ratio based methods. In opposite to classical CC, this similarity measure can handle intensity differences between images due to the usage of different sensors—multimodal images. It supposes that intensity dependence can be represented by some function. Comparison of this approach to several other algorithms developed for multimodal data can be found in Ref. [154]. In case of noisy images with certain characteristic (fixed-pattern noise), projection-based registration [27], working with accumulated image rows and columns, respectively, outperforms classical CC. Huttenlocher et al. [95] proposed a method working with other type of similarity measure. They registered binary images (the output of an edge detector) transformed by translation or translation plus rotation, by means of the Hausdorff distance (HD). They compared the HD based algorithm with the CC. Especially on images with perturbed pixel locations, which are problematic for CC, HD outperforms the CC. Two main drawbacks of the correlation-like methods are the flatness of the similarity measure maxima (due to the self-similarity of the images) and high computational complexity. The maximum can be sharpened by prepro...

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... smooth portions of object contours. Approaches based on extracting edge points are, in our opinion, more universally applicable. Huttenlocher et al. developed methods based on the Hausdorff distance =-=[14]-=-. A drawback for our purposes is that the method does not return correspondences. Methods based on Distance Transforms, such as [11], are similar in spirit and behavior in practice. Work based on shap...

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...e yellow overlay is the MAP pose and shape estimate. Segmenting the vertebra took approximately six minutes. To validate the segmentation results, we compute the undirected partial Hausdorff distance =-=[6]-=- between the boundary of the computed segmentation and the boundary of the manually-segmented ground truth. The directed partial Hausdorff distance over two point sets � and � is defined as �à �� � �Ã...

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...2], [33], [34], [35], [39], [36]. Individual objects are easier to handle, therefore, more progress has been made on efficient recognition [27], lighting-invariant [27], [28], and viewpoint-invariant =-=[22]-=-, [31] representations and recognition. Categories are more general, requiring more complex representations and are more difficult to learn; most work has therefore focused on modeling and learning. V...