Abstract: Multi-mode decoding and encoding of texture blocks are disclosed wherein in a default decoding and encoding mode all bits of a codeword sequence are available as payload bits for representing texel values of the texels in the texture block. In an auxiliary encoding and decoding mode one less bit of the codeword sequence is available as payload bits. The auxiliary mode is employed as a complement to the default mode and will be used to process those texture blocks, which the default mode handles poorly.

Abstract: A pixel block is compressed by providing a respective color component prediction for each pixel in the block. A difference between color components of two neighboring pixels is calculated and compared to a threshold. If the difference is smaller than the threshold, the prediction is calculated based on a first linear combination of the color components of these two neighboring pixels. However, if the difference exceeds the threshold, a second or third linear combination of the color components of the neighboring pixels is employed in the prediction. A guiding bit associated with the selected linear combination may be used. A prediction error is calculated based on the color component of the pixel and the provided prediction. The compressed block comprises an encoded representation of the prediction error and any guiding bit.

Abstract: A portable electronic apparatus (300) has a display (320) and a keypad (340) with a plurality of keys (342), the keys being distributed within a keypad area (341) in at least a first plane, and the keys being arranged for key-pressing user actuation transversally to the first plane so as to provide a first type of user input. The apparatus also has sensor means (430, 450, 348) positioned to sense navigating user actuation at the keypad area in or coincident with said first plane so as to provide a second type of user input, and a controller (301) configured to control a focus position (323) on the display (320) in response to user input of the second type.

Abstract: A block (300) of image elements (310) is compressed by identifying a base vector (460) based on normalized feature vectors (312) of the block (300). If a position-determining coordinate (420) of the base vector (460) is present inside a defined selection section (530) of feature vector space (500), the block (300) is compressed according to a default mode and an auxiliary mode to get a default and auxiliary compressed block (600), respectively. The compressed block (600) resulting in smallest compression error is selected. If the auxiliary mode is selected, the position-determining coordinate (420) is mapped to get a mapped coordinate (425) present outside the representable normalization portion (510) of vector space (500). The auxiliary compressed block (600) comprises a representation of this mapped coordinate (425). If the default mode is selected no such coordinate mapping is performed and the default compressed block (600) instead comprises a representation of the non-mirrored coordinate (420).

Abstract: An image block comprising multiple image elements is compressed into at least one base codeword, interval codeword and index sequence. The respective bit-length of at least two of the codewords and the index sequence are dynamically defined based on the original vector components of the image elements, though the total bit length of the resulting compressed block is constant. The base codeword represents a base value and the interval codeword represents an interval. This interval encompasses multiple component values relative the base value. The index sequence is indicative of, for each image element, a component value selected from the multiple available values.

Abstract: Compression of a pixel block having multiple pixels comprises calculating a respective prediction error for each pixel component of the pixels except a defined starting pixel. Respective minimum number of symbols required for representing the prediction errors are determined and used to select a symbol configuration among multiple different symbol configurations. Each such symbol configuration defines respective numbers of symbols maximally available for the different prediction errors. A compressed representation of the pixel block comprises a configuration identifier of the selected symbol configuration, a representation of the pixel value of the defined starting pixel and representations of the prediction errors calculated for the remaining pixels.

Abstract: The present invention relates to methods and arrangements for compressing images. The invention is based on the fact that edge blocks contain much information in one direction (across the edge), but very little information in the other direction (along the edge). By encoding edges explicitly, it is possible to obtain a high quality to a very low cost for many blocks. A block is encoded by first specifying the orientation of the edge in the block, and then specifying the profile across the edge using a function with a small number of parameters.

Abstract: In an image-encoding scheme, an input image is decomposed into image blocks comprising multiple image elements. The image blocks are then encoded into encoded blocks. An encoded block comprises a first color codeword, a second color codeword, a color modifier codeword and a color index sequence. The color codewords are representations of a first and second base color located on a first line in color space. The modifier codeword is a representation of at least one color modifier for modifying the first base color along a second line to obtain multiple color representations along the line. The second line has a different direction as compared to the first line. The index sequence comprises color indices associated with a color representation selected form i) the representations on the second line and ii) at least one representation based on the second base color.

Abstract: A pixel block (300) is compressed by sub-sampling at least a portion of the pixels (310) into subblocks (320, 330). Predictions are determined for the property values of these subblocks (320, 330) by calculating a variance measure based on property values of neighboring pixels (310)/subblocks (320, 330) in two prediction directions in the block (300) relative to a current subblock (320, 330). If the variance is below a threshold, the prediction is calculated based on neighboring property values in both directions. If the measure exceeds the threshold, the neighboring property values in only one of the two predictions directions are used for calculating the prediction. A guiding bit (450) descriptive of the selected direction is also provided. A prediction error is calculated based on the property value and the calculated prediction. The compressed block (400) comprises an encoded representation (460) of the prediction error and any guiding bit (470).

Abstract: A blurred barcode image is processed by providing an image representation thereof comprising grayscale values. The image representation is deconvoluted using a candidate motion kernel to get a deconvoluted representation. A barcode similarity measure is calculated for the deconvoluted representation to indicate how close the distribution of the grayscale values of the deconvoluted representation is to an optimal distribution for a barcode image.

Abstract: An image (1) is decomposed into multiple superblocks (20, 22), each encompassing multiple pixel blocks (30A-30D, 32A-32D) having multiple pixels (40). The property values of a superblock (20) is fixed rate compressed to get a compressed block having a target bit length. The compressed block is stored in the memory locations (310, 320) assigned to the multiple pixel blocks (30A-30D) encompassed by the superblock (20) to thereby get multiple copies of the compressed block in the memory (300). The multiple copies collectively constitute a compressed representation of the superblock (20).

Abstract: There is provided a method of selecting PMV candidates, wherein each PMV candidate corresponds to a motion vector used for coding of a previous block, said previous block having a distance from a current block. The method comprises identifying allowed distance values of distances between the current block and the previous block. The method further comprises selecting a set of PMV candidates as a subset of the set of previously coded motion vectors that were used for previous blocks having an allowed distance from the current block.

Abstract: There is provided a method of managing PMV candidates. The method comprises selecting a set of PMV candidates as a subset of the previously coded motion vectors. The method further comprises assigning a code value to each PMV candidate in the set of PMV candidates. The code values vary in length and are assigned to the PMV candidates in order of expected usage such that the PMV candidate having the highest expected usage has one of the shortest code values.

Abstract: A plurality of rows of tiles is defined in a graphics display field comprising a plurality of rows of pixels, each tile including pixels from at least two rows of pixels. Occlusion flags for respective tiles of a row of tiles for a graphics primitive are set based on whether respective representative depth values for the tiles of the row of tiles meet an occlusion criterion. Pixels in rows of pixels corresponding to the row of tiles are processed for the graphics primitive in a row-by-row manner responsive to the occlusion flags. The processing may include processing rows of pixels in the row of tiles using a zig-zag traversal algorithm.

Abstract: A method and a device for generating a pixel value from a plurality of sample values being generated from a plurality of sample points. The method comprises generating a plurality of sample values; and weighting said plurality of sample values for determining said pixel value. Each sample value is generated from one of a plurality of candidate sample points within a sample region. The sample region is positioned at a corner of two intersecting borders of the pixel. The size of the sample region is smaller than the size of the pixel. The device is arranged to carry out the method according to the invention.

Abstract: A method of retrieving information comprised in a barcode is disclosed. The method comprises detecting that the barcode is present in a first image having a first image quality and capturing a first region, acquiring, when it is detected that the barcode is present, a second image having a second image quality and capturing a second region, wherein the second image quality is higher than the first image quality, and wherein the second region at least partly overlaps the first region, and decoding the barcode based on the second image to retrieve the information. A corresponding program product and a corresponding arrangement are also disclosed along with a communication device comprising the arrangement.

Abstract: In an image scaling method, an image (10) having an original row/column resolution NO is scaled into a scaled image (30) having a target row/column resolution NT. A filter set comprising ? filters is provided, where ? being equal to a quotient of the target resolution NT and a common denominator k of the original resolution NO and the target resolution NT. The common denominator k is a positive number larger than one. For at least one row/column (16/18) of image elements (12), a filtered image element (32) of the scaled image (30) is formed, for each filter in the filter set, by filtering at least one image element (12) of the at least one row/column (16/18) using the filter. This image element formation is repeated up to k times over the at least row/column (16/18) to form a scaled row/column (36/38) of image elements (32) of the scaled image (30).

Abstract: In a high quality image-encoding scheme an input image is decomposed into several image blocks comprising multiple image elements. The image blocks are encoded into encoded block representations. Such a block representation comprises two color codewords, a color modifying codeword and optionally a sequence of color indices and color modifier indices. The color codewords define multiple discrete color representations along a line in color space. The color modifying codeword represents a set of multiple color modifiers for modifying the multiple color representations along at least one extension vector to obtain, for each color representation, a set of multiple color points. These color points of the multiple sets are located on a surface defined by the multiple color representations and the at least one extension vector. The colors of the image elements in the block are then approximated by these color points on the surface.

Abstract: The invention is applied to image processing schemes by providing at least one auxiliary block processing mode in addition to the standard default block processing mode of the scheme. An image to be decoded is divided into a number of image blocks (800) having multiple image elements (810). These blocks (800) are individually compressed by means of a default compressing mode or an auxiliary compressing mode, depending on which mode that results in a smallest error metric. A portion (980) of the resulting compressed block (900) is used to discriminate between the two modes. In the auxiliary mode, the remaining payload portion (990) of the compressed block (900) can be used for encoding purposes, whereas the default mode can in addition utilize the discriminating portion (980).

Abstract: An image encoding and decoding scheme operable according two different modes depending on properties of the processed image is disclosed. In the encoding, an image is decomposed into image blocks (600) comprising image elements (610). The blocks (600) are compressed into block representations (700A, 700B) according to one of two compression modes. A block representation (700A; 700B) comprises two codewords (720A, 730A; 720B, 730B) representing properties of the image elements (610) in the block (600) and a sequence (740A; 740B) of image element associated indices indicative of one of the codewords (720B, 730B) or a property representation generated based on a codeword (730A). The block representation (700A; 700B) also includes a mode index representing the mode, according to which the block representation (700A; 700B) was compressed. This mode index can be provided before, during or after generation of the codewords (720A, 730A; 720B, 730B) and index sequence (740A; 740B).