Automatic recognition of biological shapes using the Hotelling transform

We present two contour-based techniques, for computerized object recognitio n that avoid the difficulties due to translations, rotations and scaling. O ur techniques do not require any shape representation. The first technique uses the scale-space filtered coordinate functions of contours and their "l argest diameters". The second, uses the Hotelling transform of the vector r epresentations of the points of contours. We applied both techniques to rec ognize human corneal endothelial cells, embedded in a sample of tissue. The results obtained using the Hotelling transform represent a considerable im provement when compared to those previously obtained using the coordinate f unctions, the curvature function and Fourier descriptors as representations of shape. (C) 2001 Elsevier Science Ltd. All rights reserved.