6 Rotation invariance is an important property for operators on tensor fields, but up to now, most methods for morphology on tensor fields had to either sacrifice rotation invariance, or do without the foundation of mathematical morphology: a lattice structure. Recently, we proposed a framework for rotation-invariant mathematical morphology on tensor fields that does use a lattice structure. In...

In the application of content-based image retrieval, the ideal characteristics should be invariance to geometrical transformations. That is, once the image undergoes geometrical transformations, we expect the features extracted from the image are invariant. Thus, in this paper, rotation, scaling and translation (RST) invariant features for image retrieval are investigated, and a new method is p...

A technique for obtaining shift, rotation and scale invariant signatures for two dimensional contours in images is proposed and demonstrated. The technique is based upon a measure of the degree to which the local tangent estimate at each point in the contour is consistent with having been generated by a shift, rotation or scale invariant function. An invariance factor is calculated at each poin...

The mode of visual information processing during visuospatial tasks differs across species and is supposed to depend on evolutionary and ecological factors. Humans show reaction times that increase with angular disparity when tested in mental rotation tasks. Pigeons show a time-independent rotational invariance that possibly evolved in response to the horizontal reference plane birds perceive w...

Invariance to various transformations is key to object recognition. Image-plane invariances – such as translation, rotation and scaling – can be computed independently of the specific object. On the other hand, both invariance to rotation in depth and invariance to changes in illumination require implicit information about the 3D structure of the object or its material properties and thus more ...

In this paper, fractal transforms are employed with the aim of image recognition. It is known that such transforms are highly sensitive to distortions like a small shift of an image. However, by using features based on statistics kept during the actual decomposition we can derive features from fractal transforms which are invariant to perturbations like rotation, translation, folding or contras...

In Handwritten signatures analyzed for forgery have to undergo feature extraction process, due to varied samples in size rotation and intra-domain changes, invariance has to be achieved during feature extraction process; circular Hidden Markov Model with discrete radon transform approach of feature extraction provides invariance. On other hand Scale Invariant Feature Transform (SIFT) has inhere...

A novel moment, called 3D polar-radius-invariant-moment, is proposed for the 3D object recognition and classification. Some properties of these new moments including the invariance on translation, scale and rotation transforms are studied and proved. Then structure moment invariants are given to distinguish complicated similar shapes. Examples are presented to illustrate the performance and inv...

In this paper. an attempt is made to develop off-line recognition strategies for the isolated. handwritten English characters (A to Z. a to z). The preprocessing of characters comprises bounding of characters for translation invariance and normalization of characters for size invariance. The variability in a character introduced by the rotation and deformation is the main concern of this paper....

In this paper, a new invariant feature of two-dimensional contours is reported: the Invariance Signature. The Invariance Signature is a measure of the degree to which a contour is invariant under a variety of transformations, derived from the theory of Lie transformation groups. It is shown that the Invariance Signature is itself invariant under shift, rotation and scaling of the contour. Since...