Stmicroelectronics S.r.l.

Stmicroelectronics Gmbh

Filippo Vella

Arcangelo Ranieri Bruna

Massimo Mancuso

Antonio Vincenzo Buemi

Sebastiano Battiato

Andrea Lorenzo Vitali

Mirko Guarnera

Alfio Castorina

Stewart Gresty Smith

A method of estimating a global motion vector representative of the motion of a first digital image with respect to a second digital image, the first and the second image forming part of a sequence of images and being made up of, respectively, a first and a second pixel matrix. The method estimates the global motion vector on the basis of the estimate of at least one motion vector of at least one region of the first image representative of the motion of the at least one region from the first image to the second image and comprising phases of: subdividing the at least one region of the first image into a plurality of pixel blocks, assigning to each block of the plurality a respective weighting coefficient calculated on the basis of a respective inhomogeneity measure, and estimating the at least one motion vector of said at least one region on the basis of the weighting coefficients assigned to each block of the at least one region.

Motion estimation method and stabilization method for an image sequence

The system carries out conversion of digital video signals organized in blocks of pixels from a first format to a second format. The second format is a format compressed via vector quantization. The vector quantization is performed by means of repeated application of a scalar quantizer to the pixels of said blocks with a quantization step (Q) determined in an adaptive way according to the characteristics of sharpness and/or brightness of the pixels and representing said vector quantization in a n-dimensional space indicative of the characteristics on n of said pixels in the block partitioned into cells of size proportional to said quantization step, each cell being assigned to an appropriate binary code, wherein said process further includes identifying at least one symmetry element in said n-dimensional space suitable for separating at least two symmetrical set of cells, and selecting one of said at least two symmetrical set of cells for the assignment of said binary codes. A symmetrical permutation on the n pixels of the block is performed according the selection and a part of said binary code indicating the status of said symmetrical permutation is conveniently set.

Method and system for processing signals via perceptive vectorial quantization, computer program product therefor

A method of stabilizing an image sequence, said method comprising the following phases: estimating a first global motion vector comprising a first motion component in a predetermined direction that has associated with it a first respective amplitude and a first respective direction, said first vector being representative of the motion with respect to a reference image of a first image consisting of a pixel matrix, associating said first component with either a wanted motion or an unwanted motion, compensating said first component when it is associated with an unwanted motion, characterized in that the association phase comprises a phase of comparing the first amplitude of said component with a threshold compensation value assigned to the predetermined direction, said first component being associated with an unwanted or wanted motion whenever the first amplitude is, respectively, smaller than said threshold value or greater than/equal to it.

Method of stabilizing an image sequence

For each color channel, the process includes gathering Bayer pattern pixel values by pairs, each pair being composed by two successive pixels belonging to the channel along the scanning direction of the pixels of the image, thus each pair of values representing a current input vector, and calculating a predictor vector of the input vector in terms of the differences between the values defining the input vector and a pair of prediction values generated according to a certain criterion, for representing a prediction error. The process further includes quantizing each so calculated predictor vector according to a heavier or lighter degree of quantization depending on whether the predictor vector is representative of an area of relatively uniform color of the image or of an area of relatively abrupt changes of colors of the image, and generating a multibit code representative of the quantized predictor vector of the input vector according to a certain compression ratio.

Method and architecture for compressing image data acquired from a Bayer color filter array

A method of processing digital video signals produced by a sensor that are to be presented on a viewfinder, the method involving: a first pair of processing operations for scaling and color interpolation; and a second pair of processing operations for the formation of a color matrix and for white balancing. The operations of at least one, and preferably of both of the pairs of processing operations are executed in a single step. The operation of white balancing is moreover performed only for one frame out of K frame in the frame sequence. The preferential application is in the construction of viewfinders for videocameras and digital still cameras.

Method and system for processing video signals, for example for displaying on a small sized color display, and corresponding computer program product

A method for image compression of a set of image data includes performing a quantization operation on the image data. The quantization operation may include controlling a compression factor by applying a scaled quantization level obtained by multiplying a first quantization level by a gain factor. The gain factor may be updated as a function of a bit per pixel value of a compressed image. The update operation may include an iterative procedure including at least one iteration step that provides for updating a current gain factor as a function of a previous gain used for performing a previous compression step and as a function of a ratio of the bit per pixel value of the compressed image at the previous compression step to a target bit per pixel value. The method may be used in Joint Photographic Experts Group (JPEG) image processing and digital still cameras.

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Erice, Italy

Filippo Vella