Abstract: An apparatus and a method for adaptively calculating a start position of a series of symbols are provided. The method is applied to a frame synchronization circuit that implements the apparatus for calculating the symbolic start position of a packet-switching communication system. Even under the situations such as higher frequency offset, the frequency offset value approaching zero or unstable frequency offset, the frame synchronization circuit using the claimed method still can estimate the symbolic start position. The preferred method includes a first step of retrieving the signals in a unit of packets, and calculating their delay correlation value. Next, a control circuit is incorporated to retrieve multiple groups of symbols, and to set the parameters of the systems as a basis for identifying the system's property. After that, it's to estimate the symbolic start position.

Abstract: Device and method for calculating channel state information (CSI) are disclosed. The device and method are applied to calculate the channel state information of a dual-carrier modulation system. When a channel equalization value is transmitted into this system, an absolute-value computing unit computes the absolute value for each equalization value. The absolute-value computing unit is electrically connected to a channel classifying unit that is used to separate signals to two channels. Every channel is connected to the equalization-value comparing unit. One smaller value resulted from a comparison operation is employed as the new-defined CSI for these two channels. Afterward, this CSI can be used in a decoder for enhancing the performance of dual-carrier modulation system in a multi-path fading channel.

Abstract: A method of detecting noise in an image (1900, 2000) of a compound document is disclosed. The image comprising pixels representing at least text data (1910,1930, 2010) and image data (1920, 2020) used to form the compound document. The noise comprises at least one of halftone, bleeding and texture noise. The method partitions (120) the image into a plurality of tiles (FIG. 11) each formed of a plurality of pixels and determines (140) a set of dominant colours for each said tile and associating each pixel with one of the determined dominant colours. The method then determines (1210) for each dominant colour a fragmentation statistic (1210, FIG. 13); and applies (1220) a threshold (NoiseCnt, NoSolid, NoiseType) to each said fragmentation statistic to detect the at least one of halftone, bleeding and texture noise in the corresponding dominant colour in the tile.

Abstract: Disclosed is a method of classifying segmented contents of a scanned image of a document. The method comprise partitioning the scanned image into colour segmented tiles at pixel level. The method then generates superpositioned segmented contents, each segmented content representing related colour segments in at least one colour segmented tile. Statistics are then calculated for each segmented content using pixel level statistics from each of the tile colour segments included in segmented content, and then determines a classification for each segmented content based on the calculated statistics. The segmented content may be macroregions. The macroregions may form part of a multi-layered document representation of the document.

Abstract: An apparatus and method for estimating and compensating sampling frequency offset are disclosed. Particularly, a linear mathematical scheme is employed to calculate the related phase difference for saving use of multipliers and storage circuit used for sampling frequency offset estimation and compensation in the conventional art. The preferred embodiment of the invention has a first step to receive signals by the offset estimating circuit. Next, the phase value for each signal is calculated, and the pilot signal therein is retrieved. Next, a phase difference is obtained by subtraction operation between the received symbols and the delayed pilot symbols. And a circuit for storing the phase differences is incorporated. Next, a phase difference between the adjacent symbols is obtained by accumulating the phases and processing the least-error-sum-of-squares operation. Therefore, an estimation value of the sampling frequency offset of a communication system is obtained, and further to compensate the offset.

Abstract: The present invention provides a $ for canceling DC offset, comprising: a first circuit accumulating a first square value of a plurality of signal values in a time period; a second circuit calculation a second square value of an accumulation of said signal values in said time period, wherein said square value is divided by a quantity of said signal values in said time period to generate a DC offset value; and a third circuit, connected to said first circuit and second circuit, calculating a difference between said first square value and said DC offset value.

Abstract: A method of rendering a graphical image described by an expression tree is disclosed. The expression tree has one or more parent nodes and one or more leaf nodes, with each parent node representing a graphical operator and having branches to respective descendent nodes. Each of the leaf nodes represents a graphic object. The method determines regions of one or more pixel locations in an output space of the image, with each region corresponding to a combination in the image of one or more of the graphical objects. Next, for each of the regions, an activity state of corresponding parent nodes is determined using a predefined function for each corresponding operator. The method then generates, in parallel, for each active one of the operators, compositing instructions and pixel generation instructions. The compositing instructions are stored in an operator queue and pixel colors are generated using the pixel generation instructions, with the pixel colors being buffered in an operand queue.

Abstract: A method for estimating the signal quality of a communication channel is disclosed. Firstly, an input signal passes through a match filter at the initial stage of an estimation period. Next, the output of the match filter is calculated to obtain the noise reference value within a pre-determined period. The output value of the match filter and the noise reference value are compared. When the output value of the match filter is larger than the noise reference value, a valid power value is obtained according to the output value of the match filter. The valid power values are accumulated. Finally, a SNR is calculated according to the noise reference value and the accumulated valid power value at the end of the estimation period. Thereby, the signal quality of the wireless communication channel is estimated according to the SNR, and the signal transmission rate is determined.

Abstract: Computing an angle between a real part and an imaginary part of a complex number includes receiving complex number data; generating a first value, a second value and a determination result according to the complex number data; choosing a dividend and a divisor of a division operation from the first value and the second value for generating a division result according to magnitudes of the first value and the second value; performing table look-up for the division result to generate a table look-up result according to a preserved table; and adjusting the table look-up result for generating an angle corresponding to the complex number data according to the determination result.

Abstract: An assessment system classifies a plurality of channels to several channel groups according to the characteristics of the channel groups and assesses the status of each channel by a corresponding method, such as a period comparison method or a SNR comparison method, defined based on the channel groups. Hence, the present invention allows simpler computations to be made and a simpler circuit structure to be used.

Abstract: A packet detecting circuit detects a packet inputting time via calculating a delay correlation function and an autocorrelation function. In order to prevent a DC offset from affecting the calculation of the delay correlation function and the autocorrelation function, when the packet detecting circuit calculates the delay correlation function and the autocorrelation function, the packet detecting circuit will calculate and remove the error of the delay correlation function and the autocorrelation function produced by a DC offset. Then the packet detecting circuit calculates a packet triggering value according to the delay correlation function and the autocorrelation function for detecting the packet inputting time more precisely.

Abstract: The present invention provides a circuit for canceling DC offset, comprising: a first circuit accumulating a first square value of a plurality of signal values in a time period; a second circuit calculation a second square value of an accumulation of said signal values in said time period, wherein said square value is divided by a quantity of said signal values in said time period to generate a DC offset value; and a third circuit, connected to said first circuit and second circuit, calculating a difference between said first square value and said DC offset value.

Abstract: A Hybrid Compressor (304) and method (500) of compressing a tile (2200) of pixels within an image are disclosed. An Edge Processor (404) of the Hybrid Compressor (304) analyses pixel runs (403) of the tile (2200) and generates boundary data defining one or more regions comprising pixels of substantially identical colour. A Palette Processor (411) of the Hybrid Compressor (304) generates data defining a colour value for each region. An Image Processor (416) of the Hybrid Compressor (304) generates a representation of pixels not included in the one or more regions.

Abstract: A method (100), an apparatus, and a computer program product for automatically producing a compact representation of a colour document are disclosed. In the method, a digital image of a colour-document page is segmented (110) into connected components in one-pass, block raster order. The digital image of the page is partitioned into foreground and background images using layout analysis (120) based on compact, connected-component statistics of the whole page. At least one portion of the background image where at least one portion of the foreground image obscures the background image is inpainting (520) in one-pass block raster order. The foreground and background images are combined (130) to form a compact document. A method, an apparatus, and a computer program product for segmenting a digital image comprising a plurality of pixels are also disclosed.

Abstract: A screwless device for attaching and detaching a disk drive comprises a base and a frame body. The base comprises at least a rotation bracket, an elastic location plate, a fixing plate, and protrudent joints. Two first axle holes are located on both sides of the rotation bracket respectively for being inserted by an axle to which a torsion spring is sleeved. A buckle hole is formed on the elastic location plate. The frame body is designed for being attached to the base. The frame body comprises: a mounting chamber for holding the disk drive; an axle-connecting part; and a buckle means mounted on the same side of the frame body as the elastic location plate. Second axle holes and buckle notches are formed on the axle-connecting part. Several open trenches are formed in opposition to the protrudent joints.

Abstract: Disclosed is a method of detecting a predetermined mark embedded in an image. The mark (29) comprises a predetermined arrangement of a plurality of elements (30), each element having a predetermined colour characteristic and predetermined shape. The method processes (20) the image to provide an encoded representation of the image at a predetermined resolution (eg. 200 dpi). The coordinate positions for substantially each of the elements of the mark embedded in the image are detected (22), wherein the detection is characterised by applying at least one mask (80) to substantially each pixel of the encoded representation. From the coordinate positions, a set of spatial features representing a spatial arrangement of the detected elements are then determined (23). The determined set of spatial features is then compared (24) to a known set of spatial features to provide a confidence level measure for a degree of matching between the known set and the determined set of spatial features.

Abstract: A method, an apparatus (100) and a computer program product for entropy coding of discrete wavelet transform (DWT) coefficient bits that are arranged into code blocks and coded in bitplane order using three coding passes for each bitplane are disclosed. In the method, transform coefficients of a code block (200) in sign-magnitude form are pre-analyzed. Statistical data about the coefficients is stored, preferably with the coefficients. Significance state data (330), coded data (340), magnitude refinement data (350), bit data (310), and sign data (320) for the code block are buffered. More preferably, the buffering is implemented using a FIFO (120, 1130), located between a context generation module (110, 1120) and an arithmetic coder (130, 1150). Based upon the statistical data, at least one command for at least one sequence of bit and context pairs is generated for arithmetic encoding.

Abstract: A method of rendering a graphical image described by an expression tree is disclosed. The expression tree has one or more parent nodes and one or more leaf nodes, each parent node representing a graphical operator and having branches to respective descendent nodes. Each of the leaf node represents a graphic object. The method determines regions of one or more pixel locations in an output space of the image, with each region corresponding to a combination in the image of one or more the graphical objects. Next, for each said region, an activity state of corresponding parent nodes is determined using a predefined function for each corresponding operator. The method then generates, in parallel (1098), for each active one of the operators, compositing instructions and pixel generation instructions. The compositing instructions are stored in an operator queue and pixel colors are generated using the pixel generation instructions, the pixel colors being buffered in an operand queue (1300).

Abstract: Disclosed is method of detecting a predetermined mark (30) forming part of an image. A digitized form (48, 49) of the image (21) comprising a plurality of picture elements is provided and within a current region of the image a set of features is determined. The features typically comprise a dominant color feature (44) within the current region; and at least one moment feature (111) based on picture elements pertaining to the predetermined mark within the current region. Each determined feature is compared (113) with a corresponding predetermined feature (114) of the predetermined mark. Using the comparison, a confidence level for a detection of said predetermined mark within the current region calculated. Based on the confidence level, whether or not said predetermined mark is detected in the current region can then be determined.

Abstract: A compositing system (300) that comprises an optimized alpha-channel compositing module (303) is disclosed. The compositing system (300) optimizes the range correction in the alpha-channel compositing module (303) by using a constant divider (401) and delaying the correction of an alpha value until after the summation of the alpha values from all contributing regions. Uncorrected opacity values are used to index a look-up table in order to reduce the data processing path to a multiplier (407) for processing after premultiplication of a color values from all contributing regions.