Abstract: A communications circuit includes a filter module with a sampling window, a control module, and an input buffer. The control module has a ray parameter interface to obtain information regarding significant ray changes that make it desirable to re-position the sampling window. The control module determines re-positioning parameters, responsive to this information, which reflect the re-positioning of the sampling window. The input buffer obtains samples of a received signal and outputs received signal data to the filter module. The filter module obtains the re-positioning parameters from the control module, and the filter module and control module temporally re-position the sampling window in duration and/or location in accordance with the re-positioning parameters, and output a filtered chip.

Abstract: A multi-stage receiver including, in one embodiment, a sequence of processing stages. At least one of the processing stages includes a first processing block, a delay block, and a second processing block. The first processing block is adapted to receive an input signal and generate from the input signal one or more processing parameters. The delay block is adapted to generate a delayed signal. The second processing block is adapted to apply the one or more processing parameters to the delayed signal to generate an output signal. The delay block compensates for one or more processing delays associated with the generation of the one or more processing parameters by the first processing block.

Abstract: A communications circuit can operate with a data channel and a control channel. A changeable portion of the circuit can be reconfigurable between a first mode associated with activity on the control channel only and a second mode associated with activity on both the data channel and the control channel. The first mode can be selected to reduce power consumption compared to the second mode. Controller circuitry is provided to sense signals associated with the control channel and to switch the changeable portion between the first and second modes.

Abstract: Disclosed is a method and apparatus for clamping the output values of filtered image data comprising a mapping of discrete sample values are disclosed. For each discrete sample value of the mapping a maximum sample value and a minimum sample value of a plurality of input discrete samples values used to calculate the discrete sample value, is determined. The output value of the discrete sample value is clamped to the domain of the plurality of input discrete sample values utilising the maximum sample value and the minimum sample value, wherein the output value is dependent on a plurality of attributes of the plurality of input discrete sample values.

Abstract: The span of a linear transversal equalizer filter moves according to the current positions of the multi-paths to a receiver. The alignment of the filter span is measured quantitatively with respect to the current positions of the multi-paths. Adjustments are made to the filter span to enable the linear transversal filter to capture most of the available energy of the transmitted signal. The low-pass-filtered magnitudes of tap weights of the linear filter are multiplied with values of a function which has zeroes at desired points for the larger tap weights, and a gradient of the function at its zeroes being non-zero. The magnitude of the alignment measurement signal is used as a quantitative measure of the alignment of the equalizer span, while the sign of the alignment measurement signal can be used to decide the direction that the span should be moved in.

Abstract: A communications circuit can operate in a first mode, such as a diversity mode including space time transmit diversity (STTD). In this mode, a number of equalizer filter portions connected to a number of post-equalizer processors are employed. When the diversity mode is not required, the extra equalizer filter portions would represent a waste of power consumption and/or chip space. A combining circuit and suitable control circuitry are provided to allow use of the additional equalizer filter portions to be made in other operating modes. Appropriate trade-offs can be made based on power consumption and performance.

Abstract: The preferred method wavelet filters a digital image. The digital image comprises a plurality of pixels arranged in a plurality of columns and rows. The method processes one or more bands of pixels of the image in turn, where each band comprises a plurality of rows. The method performs the following steps for each column in each one of the one or more bands of pixels. The method retrieves (316) a last pixel and last high pass coefficient previously stored in local storage. The method also inputs (306) a current group of adjacent pixels. The method then computes (308) the low and high pass wavelet coefficients utilizing the current group of adjacent pixels and the previous last pixel and last high pass coefficient. The method then outputs the low and high pass coefficients, and stores (312, 318) a current last pixel and high pass coefficient in either the local storage or external memory.

Abstract: A method and apparatus (9) for estimating the blur parameters of blurred images (g1, g2) are disclosed. The apparatus (9) has one or more image sensors (10) for capturing the blurred images (g1, g2), a plurality of correlators (20, 30) for performing autocorrelation of the blurred image (g1) and cross-correlation between the two images (g1, g2) respectively, and an error function calculator (40) for evaluating an error function over all possible displacements using the results from the correlators (20, 30). The apparatus (9) further includes an extreme locater (50) for finding the displacement with the minimum value for the error function.

Abstract: A method of resolution conversion is disclosed. The method calculates a scaling factor for a first set of discrete data values compared to said second set of discrete data values. A plurality of filter function coefficients are calculated, based on the scaling factor, utilising at least one of a plurality of filter functions. The filter function coefficients are stored and later used to perform interpolation on the first set of discrete data values to generate the second set of discrete data values at a different resolution.

Abstract: The method encodes a digital image to provide a compressed representation of the image. The method initially performs a multi-level 2-D Discrete Wavelet Transform on the digital image, which is arranged in a hierarchical order of sub-bands. The method then tiles each sub-band to form a number of blocks of transform coefficients. The method then encodes each bitplane of each block from a maximum bitplane to a minimum bitplane in the following manner. The method divides a current bitplane into a number of first areas and/or a number of second areas, wherein each first area comprises a number of coefficients having corresponding most significant bits in the current bitplane or less and each second area comprises a number of coefficients having corresponding most significant bits in a bitplane greater than the current bitplane. The method then codes the significance of each first area in the current bitplane; and codes a corresponding bit of each coefficient in each second area of the current bitplane.

Abstract: There is disclosed apparatus (106) for accessing items of information. The apparatus (106) comprises sixteen memory banks (202) and an address generator (204). Each of the sixteen memory banks (202) stores items of information associated with and corresponding to respective symbols of a sub-set of the symbols. These sub-sets of symbols are mutually exclusive and together comprise a set of symbols. The items of information of the sixteen memory banks (202) together constitute the whole of the items of information associated with and corresponding to the respective symbols of the set of symbols with no duplication of the items of information. The address generator (204) simultaneously generates sixteen addresses for the respective sixteen memory banks (202) in response to one input address, wherein the memory banks (202) output sixteen items of information associated with and corresponding to the respective symbols within a 4×4 neighbourhood of the symbol corresponding to said input address.

Abstract: A method of entropy coding symbols representative of a code block comprising transform coefficients of a digital image. The method comprises a significance propagation pass 314, a magnitude refinement pass 316, and a cleanup pass 318 for entropy coding the symbols. The method generates (1210,1211), prior to the significance propagation pass 314 of the current bitplane, a first list of positions of those coefficients in the code block that have symbols to be entropy coded during the significance propagation pass of the current bitplane. The method also generates (1208), prior to the magnitude refinement pass 316 of the current bitplane, a second list of positions of those said coefficients in the code block that have symbols to be entropy coded during the magnitude refinement pass of the current bitplane.

Abstract: The method decodes an compressed representation of a digital image. The compressed representation is in the form of a bitstream comprising in sequence encoded bitplanes each having first portions representative of the significances of first sub-regions in the current bitplane and second portions representative of respective bits of each coefficient in second sub-regions of the current bitplane. The method decodes each bitplane of a block of transform coefficients from a maximum bitplane to a minimum bitplane in the following manner. The method decodes the first portion as the respective significances of the first sub-regions in the current bitplane and decodes the second portion as the respective bits of each coefficient in the second sub-regions of said current bitplane.

Abstract: An apparatus is disclosed for decoding a stream of previously encoded coefficients including input means for receiving the stream of encoded coefficients; bit plane level monitoring means connected to the input means and adapted to monitor a current bit plane level from the stream of coefficients; pixel generation means interconnected to the input means and the bit plane level monitoring means and adapted to utilize the current bit plane level for generating output coefficient values each having a predetermined size.

Abstract: A method of entropy coding symbols representative of a code block comprising transform coefficients of a digital image. The method comprises a significance propagation pass 314, a magnitude refinement pass 316, and a cleanup pass 318 for entropy coding the symbols. The method generates (1210,1211), prior to the significance propagation pass 314 of the current bitplane, a first list of positions of those coefficients in the code block that have symbols to be entropy coded during the significance propagation pass of the current bitplane. The method also generates (1208), prior to the magnitude refinement pass 316 of the current bitplane, a second list of positions of those said coefficients in the code block that have symbols to be entropy coded during the magnitude refinement pass of the current bitplane.

Abstract: The preferred method wavelet filters a digital image. The digital image comprises a plurality of pixels arranged in a plurality of columns and rows. The method processes one or more bands of pixels of the image in turn, where each band comprises a plurality of rows. The method performs the following steps for each column in each one of the one or more bands of pixels. The method retrieves (316) a last pixel and last high pass coefficient previously stored in local storage. The method also inputs (306) a current group of adjacent pixels. The method then computes (308) the low and high pass wavelet coefficients utlising the current group of adjacent pixels and the previous last pixel and last high pass coefficient. The method then outputs the low and high pass coefficients, and stores (312, 318) a current last pixel and high pass coefficient in either the local storage or external memory.

Abstract: A method and apparatus (9) for estimating the blur parameters of blurred images (g1, g2) are disclosed. The apparatus (9) has one or more image sensors (10) for capturing the blurred images (g1, g2), a plurality of correlators (20, 30) for performing autocorrelation of the blurred image (g1) and cross-correlation between the two images (g1, g2) respectively, and an error function calculator (40) for evaluating an error function over all possible displacements using the results from the correlators (20, 30). The apparatus (9) further includes an extreme locater (50) for finding the displacement with the minimum value for the error function.

Abstract: The present invention relates to an image processor (242) comprising a control register block (1470), a decoding block (1468), a data object processor (1462), and flow control logic. The control register block (1470) stores all the relevant information about the image processing operation. The decoding block (1468) decodes the information into configuration signals, which configure an input data object interface (1460). The input data object interface (1460) accepts and stores data objects from outside, and distributes these data objects to the data object processor (1462). For some image processing operations, the input data object interface (1460) may also generate addresses for data objects, so that the source of these data objects can provide the correct data objects. The data object processor (1462) performs arithmetic operations on the data objects received. The flow control logic controls the flow of data objects within the data object processing logic (1462).

Abstract: An apparatus for the encoding of a series of wavelet coefficients of a predetermined size into a compact representation of the coefficients. The apparatus comprises a tree builder for constructing a tree form representation of the coefficients with leaf nodes representing coefficient values and internal nodes representing the number of bits needed to encode leaf nodes and child nodes of a current internal node. The tree builder stores the tree form representation in a tree buffer of the apparatus, and the tree buffer stores the tree form representation. A tree coder of the apparatus is interconnected to the tree buffer and adapted to read a current tree form representation and to output the encoding from the tree form representation.