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We describe a widely applicable method of grouping-or clustering-image features (such as points, lines, corners, flow vectors and the like). It takes as input a "proximity matrix" H-a square, symmetric matrix of dimension N (where N is the number of features). The element i,j of H is an initial estimate of the "proximity" between the i-th and yth features.(More)
Studies of synaptogenesis in the developing organ of Corti in the intact mouse and in culture indicate that the inner and outer hair cells contain three populations of synaptic ribbons, i.e. ribbons adjacent to nerve fibres, free intracellular ribbons and misplaced ribbons apposed to non-neuronal elements. Ribbons adjacent to nerve fibres can be further(More)
We describe a form of damped wave process which appears to have considerable promise in early vision analysis. We demonstrate in particular its use in eliciting a version of the Symmetry Set-the locus of centres of circles bitangent to a curve. The wave process is a method of implementing the "Symmetry Transform" of an image, which we define and discuss(More)
In this paper I introduce a new way of generating and describing shapes which was largely inspired by reading D'Arcy Thompson's classic "On Growth and Form" [1]. There are suggestive parallels between my system and "coupled oscillation" models of handwriting [2] and locomotion [3]. Like many others the system involves a mapping from a space of "implicit(More)
We have compared the biochemical expression of cholinergic enzymes with the morphological differentiation of efferent nerve fibers and endings in the cochlea of the postnatally developing mouse. Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) are present in the newborn cochlea at specific activities 63% and 25%, respectively, of their(More)
A relaxation algorithm for the computation of optic flow at edge elements (edgels) is presented. Flow is estimated only at intensity edges of the image. Edge elements , extracted from an intensity image, are used as the basis for the algorithm. A matching strength or weight surface is computed around each edgel and neighbourhood support obtained to enhance(More)
Hildreth described a method of extracting the normal component of optic flow along a moving closed contour. She also described an algorithm-based on gradient descent of recovering the smoothest full flow field consistent with the normal flow. Her iterative method is somewhat slow. It also leaves open the question of what, if anything, we are going to say(More)
A case of aortic valve replacement with a Björk-Shiley disc prosthesis in a patient with sickle-cell trait is presented. Six months after operation red cell survival was not significantly reduced. On theoretical and clinical grounds it is concluded that the presence of sickle-cell trait does not contribute to late postoperative haemolysis after heart valve(More)