Sgs-thomson Microelectronics S.r.l.

Stmicroelectronics S.r.l.

Consorzio Per La Ricerca Sulla Microelettronica Nel Mezzogiorno

Scs Thompson Microelectronics, S.r.l.

Rinaldo Poluzzi

Massimo Mancuso

Gianguido Rizzotto

Andrea Pagni

Viviana D'Alto

Alessandro Cremonesi

Franco Cavallotti

Dario Bruno

Eleonora Franchi

Claudio Luzzi

Alberto Amilcare Savi

Federico Travaglia

Biagio Russo

Laura Pennino

Luca Molinari

Matteo Lo Presti

Mario Lavorgna

Michele Taliercio

Fabrizio Airoldi

Fabio Scalise

Giuseppe D'Angelo

Nicol&ograve; Manaresi

Daniele Sirtori

Federica Colla

Giuseppe Martina

Maddalena Di Giura

Davide Vago

Cristoforo Mione

Ricardo Alberto Marques Pereira

Paolo Moretti

A post-processing method reduces artifacts in block-coded digital images. The method includes: dividing an input image into a plurality of image blocks; for each image block, estimating global features of said image block providing information on an average content of image edges along the horizontal and vertical directions of said image block; for each pixel of an image block under examination, estimating local features for said pixel providing information on the content of image edges along the horizontal and vertical directions of an image area near said pixel; modifying the value of said pixel according to both said global features of the image block to which said pixel belongs and said local features of the image area near said pixel.

Post-processing method for reducing artifacts in block-coded digital images, and post-processing device for actuating such method

A device for filtering electrical signals has a number of inputs arranged spatially at a distance from one another and supplying respective pluralities of input signal samples. A number of signal processing channels, each formed by a neuro-fuzzy filter, receive a respective plurality of input signal samples and generate a respective plurality of reconstructed samples. An adder receives the pluralities of reconstructed samples and adds them up, supplying a plurality of filtered signal samples. In this way, noise components are shorted. When activated by an acoustic scenario change recognition unit, a training unit calculates the weights of the neuro-fuzzy filters, optimizing them with respect to the existing noise.

Device and method for filtering electrical signals, in particular acoustic signals

A neuro-fuzzy filter device that implements a moving-average filtering technique in which the weights for final reconstruction of the signal are calculated in a neuro-fuzzy network according to specific fuzzy rules. The fuzzy rules operate on three signal features for each input sample. The signal features are correlated to the position of the sample in the considered sample window, to the difference between a sample and the sample at the center of the window, and to the difference between a sample and the average of the samples in the window. The filter device for the analysis of a voice signal includes a bank of neuro-fuzzy filters. The signal is split into a number of sub-bands, according to wavelet theory, using a bank of analysis filters including a pair of FIR QMFs and a pair of downsamplers; each sub-band signal is filtered by a neuro-fuzzy filter, and then the various sub-bands are reconstructed by a bank of synthesis filters including a pair of upsamplers, a pair of FIR QMFs, and an adder node.

Filtering device and method for reducing noise in electrical signals, in particular acoustic signals and images

The fuzzy filtering of a noise signal comprising a plurality of signal samples &lsqb;s(t,k)&rsqb; is carried out using as variables the variation of the signal in the considered window and the distance of the samples from a sample to be reconstructed, to distinguish the typical variations of the original signal from those due to the noise and to identify the signal fronts. The method comprises the steps of defining a current signal sample &lsqb;s(t)&rsqb; from among the plurality of signal samples, calculating a plurality of difference samples &lsqb;D(t,k)&rsqb; as the difference in absolute value between the current signal sample and each signal sample and defining distance values (k) between the current signal sample and each signal sample. The method further comprises determining weight parameters &lsqb;P(k)&rsqb; on the basis of the difference samples and the distance values by means of fuzzy logic and weighing the signal samples with the weight parameters so as to obtain a reconstructed signal sample &lsqb;o(t)&rsqb;.

Fuzzy filtering method and associated fuzzy filter

The filter includes an arithmetical chain of parallel adders alternated with delay elements, and a memory constituted by lines of one-bit cells. Each line is addressable by a decoder controlled by a digital signal to be filtered; each line of memory contains side by side values which correspond to the partial products of successive impulse-response coefficients for a value equal to the line address. The memory additionally includes a number of read amplifiers. The number of read amplifiers is equal to the number of cells of one line in order to read the bits of the addressed. The outputs of the amplifiers are connected to respective parallel inputs of the adders of the arithmetical chain. Each memory line contains these values in two's-complement binary form in words which decrease in length by one bit for each increment of 2 in the characteristic of the coefficients, starting from the one of lowest characteristic. The output of each read amplifier corresponding to the most significant bit of each value is connected to the corresponding input bit line of the associated adder and to all the other most significant input bit lines.

Memory for programmable digital filter

The analog processor of this invention is programmable and capable of storing the processing coefficients in analog form. It comprises a storage section having at least one output, plural outputs in most cases, and being adapted to respectively generate programming signals on such outputs; the storage section is input a plurality of supply voltage signals and is operative to produce, in connection with information stored therein, one of the supply voltage signals on each of the outputs, it being understood that one voltage signal may be produced on several such outputs. Advantageously, the processor can also be programmed in a simple manner from circuits of the digital type if switches controlled by storage elements are used in the storage section.

Programmable fuzzy analog processor

A digital image color correction device and method employing fuzzy logic, for correcting a facial tone image portion of a digital video image is provided. The device is a pixel fuzzifier unit (,) receiving in input a stream of pixels belonging to a sequence of correlated frames of a digital video image and computing a multilevel value representing a membership of each pixel to a skin color class; a global parameter estimator (,) receiving in input each of said pixel and the relative membership value, and computing a first and a second parameter which define the characteristics of a portion of said image that belongs to said skin color class; a processing unit (,) connected downstream to said global parameter estimator and to said pixel fuzzifier unit and adapted to correct each of the pixels of said portion of the image that belongs to said skin color class, according to said first global parameter (,), to obtain corrected pixels; and a processing switch (,) for outputting said pixels or said corrected pixels according to said second global parameter (,).

Digital image color correction device and method employing fuzzy logic

A digital photography apparatus, particularly a digital still camera, includes circuit portions for acquiring a digital image, and for obtaining a compressed image. The apparatus also includes a memory for storing the compressed image. A processor is provided for obtaining a processed image and corresponding processing parameters from the image acquired. The processor supplies as an output, in a first operative condition, the processed image to be compressed by the compression circuit portion. In a second operative condition, the processor supplies as an output the image acquired to be compressed by the compression portion and the processing parameters to be stored in the memory.

Digital photography apparatus with an image-processing unit

A method and a device for motion estimated and compensated Field Rate Up-conversion (FRU) for video applications is disclosed and claimed. The invention provides for dividing an image field to be interpolated into a plurality of image blocks, where each image block includes a respective set of image elements of the image field. In one embodiment, for each image block of a subset of image blocks, a group of neighboring image blocks is selected. A motion vector for the image block is estimated that describes the movement of the image block from a previous image field to a current image field on the basis of predictor motion vectors associated to the group of neighboring image blocks. Each image element of the image block is determined by interpolation of two corresponding image elements in the previous and current image fields related by the estimated motion vector. To estimate a motion vector, the invention provides for applying each of the predictor motion vectors to the image block to determine a respective pair of corresponding image blocks in the previous and current image fields. For each of the pairs of corresponding image blocks, an error function which is the Sum of luminance Absolute Difference (SAD) between corresponding image elements in the pair of corresponding image blocks is evaluated. For each pair of the predictor motion vectors, a degree of homogeneity is also evaluated, followed by the application of a fuzzy rule having an activation level that is proportional to the degree of homogeneity of the pair of predictor motion vectors and the error functions of the pair of predictor motion vectors. An optimum fuzzy rule having the highest activation level is selected, from which the best predictor motion vector is determined, having the smaller error function of the pair associated to the optimum fuzzy rule. In most cases, the motion vector for the image block is estimated on the basis of the best predictor motion vector.

Method for motion estimated and compensated field rate up-conversion (FRU) for video applications and device for actuating such method

The level of Gaussian noise in a memory field being scanned by rows is reduced by reconstructing each pixel by fuzzy logic processors. The processors process the values of pixels neighboring the pixel being processed and belonging to a processing window defined by the last scanned row and the row being scanned, thus minimizing the memory requirement of the filtering system to a single row. The system performs an adaptive filtering within the current field itself and does not produce &ldquo;edge-smoothing&rdquo; effects as in prior adaptive filtering systems operating on consecutive fields.

Adaptive intrafield reducing of Gaussian noise by fuzzy logic processing

A filter performs a reduction of pulsed noise in video images in accordance with fuzzy logic. An interface circuit of the filter receives consecutive digital signals in time corresponding to the video images and generates an image window having a digital signal to be processed at the center. The filter also has a comparator block, a plurality of digital subtractors, and a memory circuit connected in cascade to the comparator block. The filter also has a filtering circuit that organizes values of digital signals of the video image, and an arithmetic block that performs a switch between the digital signal to be processed and the output of the filtering circuit on the basis of the values taken by the parameter.

Fuzzy logic filter for impulsive noisy images

A processing device for video signals has a memory device suitable to store discrete image elements of a video field and a filtering device supplied by the memory device and suitable to recover errors introduced by the memory device. The filtering device includes a filter, noise detector means, and soft-switch means. The filter has an input supplied with digital signals representative of values of a plurality of discrete image elements and comprises an image element to be examined and neighboring image elements. The discrete image elements is stored in the memory device, and an output supplying digital signals representative of a filtered value of the image element to be examined. The noise detector means operating on fuzzy-logic rules has an input supplied with the digital signals representative of the plurality of values of the image elements and an output supplying a weight signal representative of a degree of erroneousness of the discrete image element to be examined. The noise detector circuit determines the degree of erroneousness by comparing the value of the image element to be examined with the values of the neighboring image elements. The soft-switch means has a first, second and third input and an output. The first input is supplied with the digital signals representative of the value of the image element to be examined. The second input is supplied with the output of the filter. The third input is supplied with the weight signal. The output supplies digital signals representative of a weighted average of the output of the filter and of the digital signals representative of the value of the image element to be examined according to respective weights determined by the degree of erroneousness.

Processing device for video signals

An interpolation filter for video signals includes four circuits to improve video quality in both intra-field and inter-field modes. The interpolation filter is configured to interpolate according to the direction of an image edge. The interpolation filter is also configured to interpolate in a prescribed spatial direction when no image edges can be univocally determined. The first circuit detects an image edge of discrete image elements to generate a first signal. The second circuit uses output from the first circuit to generate a first signal corresponding to an average of the discrete image elements along a direction of the image edge. The third circuit uses output from the first circuit to detect a texture image area wherein an image edge cannot be univocally determined and for generating a second signal depending on a degree of existence of the image edge. The fourth circuit is supplied by the first signal, the second signal and a third signal. The fourth circuit generates an output signal obtained by combining the first signal with the third signal in a proportion dependent upon the second signal. Additionally, the fourth circuit is configured for multiplexing to selectively couple the third signal to a fourth signal, corresponding to an average of the discrete image elements along a prescribed direction, or to a fifth signal corresponding to a previously received image element value.

Edge-oriented intra-field/inter-field interpolation filter for improved

The analog processor can carry out processings independently of the operating temperature and process parameters, in a reliable manner and at high performance levels using fairly simple circuitry. To achieve this independence, the processor is basically implemented and integrated with MOS transistors, has both voltage inputs and outputs, and includes a biasing section which supplies voltage bias signals, of which at least one is substantially the sum of a voltage proportional to the threshold voltage of the MOS transistors and a reference voltage. This reference voltage can be extracted from a reference potential which is stable to temperature and process parameters, for example that produced by a bandgap type of generator. A major feature of the processor according to the invention is the linearity of its input-output characteristic relative to that reference voltage. It follows that it may be advantageous to extract that reference voltage by division from a signal indicating the width of the input signal variation range, thereby to achieve compensation for or independence of variations of this range.

Fuzzy analog processor with temperature compensation

A method for recognizing geometric shapes in an image using fuzzy logic. The method includes determining an edge in the image and a gradient of the edge. The gradient is corrected by virtue of a first fuzzy logic process, and the number of points that belong to the curve are determined by virtue of a second fuzzy logic process. A fuzzy device for the recognition of geometric shapes in images that implementing the method includes an edge detector, a fuzzy gradient corrector to correct the gradient, and a fuzzy vote attributor to determine the number of points that belong to the curve.

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Milan, Italy

Rinaldo Poluzzi