123results about How to "Reduce blockiness" patented technology

Processing to reduce blocking artifacts in an image comprising a first image block and a second image block separated by a block boundary, includes, generating a main gradient value which is a function of a first pixel difference between a first pixel located in the first image block a second pixel located in the second image block, where the first and second pixel are located adjacent to each other on a first axis running vertically relative to the block boundary. In addition, at least one secondary gradient value is generated which is a function of a second pixel difference between at least two pixels located adjacent to each other in the first image block on the first axis, and a function of a third pixel difference between at least two pixels located adjacent to each other in the second image block on the first axis. The first and second image blocks are filtered, at least in the region of a block boundary between the first and second image blocks as a function of a ratio between the main gradient value and the at least one secondary gradient value.

An apparatus and method which includes estimating a motion vector of a frame and / or field to be interpolated and the accuracy of the motion vector using motion vectors of previous and next frames and / or fields; determining motion information by analyzing the estimated motion vector, and calculating a correlation between the motion vector of the current block and the motion vectors of neighboring blocks; generating pixels to be interpolated by performing motion compensation in a frame and / or field to be interpolated using the estimated motion vector and using pixels neighboring a pixel to be interpolated in the frame and / or field to be interpolated and pixels neighboring a pixel to be interpolated in the previous and next frame and / or field of the pixel to be interpolated; and outputting the generated pixels as interpolation values according to the accuracy of the estimated motion vector, the motion information, and the correlation.

A loop-filtering method for reducing quantization effect generated when an image data is encoded and decoded, and an apparatus therefor. The loop-filtering method includes the steps of extracting a flag indicating whether the image data requires loop-filtering using the distribution of inverse quantized coefficients (IQCs) of an inverse quantized image data and a motion vector indicating the difference between the previous frame and the current frame. The image data corresponding to the flag is then filtered by a predetermined method if the extracted flag indicates a need for the loop-filtering. Using the flags and an adaptive filter reduces the quantization effect and is useful to reduce the amount of computation required for the filtering. Also, the filtering can be performed through parallel processing without multiplication and division, so that the complexity of hardware can be reduced.

The invention discloses an image dehazing method and system based on a dark channel and a non-local prior, which belongs to the technical field of image information processing. The image dehazing method can reasonably recover a degraded image collected in the haze weather. The method comprises the following steps of (1) calculating a dark channel image of a hazed image; (2) estimating the atmospheric light intensity of the hazed image according to the dark channel image; (3) estimating the transmissivity of the image based on the non-local prior; (4) correcting a transmittance image; and (5) using an atmospheric scattering model to restore a dehazed image. The invention also discloses an image dehazing system based on the dark channel and the non-local prior. The invention can restore scene information in the image realistically and naturally, and the algorithm has the advantages of low complexity, fast running speed and wide application prospect.

A system and method facilitating progressively transforming and coding digital pictures is provided. The present invention via employment of a multi-resolution lapped transform provides for progressive rendering as well as mitigation of blocking artifacts and ringing artifacts as compared to many conventional compression systems. The invention includes a color space mapper, a multi-resolution lapped transform, a quantizer, a scanner and an entropy encoder. The multi-resolution lapped transform outputs transform coefficients, for example, first transform coefficients and second transform coefficients. A multi-resolution representation can be obtained utilizing second transform coefficients of the multi-resolution lapped transform. The color space mapper maps an input image to a color space representation of the input image. The color space representation of the input image is then provided to the multi-resolution lapped transform. The quantizer receives the first transform coefficients and / or the second transform coefficients and provides an output of quantized coefficients for use by the scanner and / or the entropy encoder. The scanner scans the quantized coefficients in order to produce a one-dimensional vector for use by the entropy encoder. The entropy encoder encodes the quantized coefficients received from the quantizer and / or the scanner resulting in data compression.

A frame interpolator comprises a motion estimating unit dividing a current frame into a plurality of reference blocks, each reference block having a predetermined size, comparing the reference block with a predetermined search area set in a previous frame, and estimating an initial motion vector. A reliability evaluating unit evaluates reliability of the initial motion vector and generates reliability evaluation data regarding the evaluation result. A frame interpolating unit interpolates an intermediate frame to be inserted between the current frame and the previous frame on the basis of the initial motion vector and the reliability evaluation data A frame interpolator, a frame interpolation method, and a motion reliability evaluator, which are capable of improving interpolation quality of frames and reducing a block artifact, are provided.

Methods of image interpolation disclosed herein include a method of irregular-grid expanded-block weighted motion compensation (IEWMC) and a method of block-wise directional hole interpolation (BDHI). The IEWMC can be used with unidirectional motion or disparity trajectories. The IEWMC can be applied in both forward and backward directions, and the interpolated images resulting from IEWMC application can be superimposed, or averaged, to reduce the blocking artifacts and handle the holes and overlaps. The BDHI takes into account the orientation of local edges and textures when filling the holes, which results in a sharper interpolated image.

Disclosed is an apparatus and method for compensating for estimated motion vectors by deciding whether a pattern image exists in target blocks for motion estimation. A motion estimation part compares a current block of a current frame / field to a search area established in a previous frame / field, calculates plural motion estimation error values, and estimates a temporary motion vector of the current block based on the plural motion estimation error values. A pattern decision part analyzes the calculated motion estimation error values, and decides that the current block is a pattern image. A motion compensation part produces a compensation motion vector of the current block by use of the plural motion estimation error values if the current block is decided as the pattern image. A motion vector selection part selects a final motion vector based on a result of the pattern decision part.

The invention relates to a super-resolution image reconstruction method based on analysis sparse representation, belonging to the technical field of image processing. The method comprises the following steps of: performing dictionary training according to a training sample set; and training a high-resolution dictionary and a low-resolution dictionary for an extracted feature; converting an image to be input from an RGB (Red, Green and Blue) space into a 1 alpha beta space and dividing into blocks of a same size; performing two kinds of operation on the blocks, wherein one is that each block is amplified by using the conventional amplification method and the other one is that an residual image of each block is extracted, sparse representation of the residual image in the low-resolution dictionary is calculated, and then the residual image is reconstructed in the high-resolution dictionary to obtain a reconstructed residual image; summarizing results of the two steps, converting back into the RGB space and performing back projection to obtain the reconstructed super-resolution image. According to the method, the image reconstruction noise can be obviously reduced, and detail features are kept; and meanwhile, the method has the advantages of easiness in operation and wide application.

A method of coding a moving picture is provided that reduces blocking artifacts. The method can include defining a plurality of defining pixels S0, S1, and S2, which are centered around a block boundary. If a default mode is selected then frequency information of the surroundings of the block boundary is obtained. A magnitude of a discontinuous component in a frequency domain belonging to the block boundary is adjusted based on a magnitude of a corresponding discontinuous component selected from a pixel contained entirely within a block adjacent the block boundary. The frequency domain adjustment is then applied to a spatial domain. Or, a DC offset mode can be selected to reduce blocking artifacts in smooth regions where there is little motion.

The invention provides an object and fractal-based binocular three-dimensional video compression and decompression method. In binocular three-dimensional video coding, a left channel is used as a basic layer, a right channel is used as an enhancement layer, and the left channel is encoded by an independent motion compensation prediction (MCP) mode. The object and fractal-based binocular three-dimensional video compression coding method comprises the following steps of: firstly, acquiring a video object partition plane, namely an Alpha plane by a video partition method, encoding the initial frame of a left eye through block discrete cosine transformation (DCT), and performing block motion estimation / compensation coding on a non-I frame of the left eye; secondly, determining the area attribute of an image block by utilizing the Alpha plane, and if the block is not within a video object area of the current code, not processing an external block, and if the block is within the video object area of the current code completely, searching the most similar matching block by a full-searching method in a previous frame of an internal block, namely a reference frame searching window of a left eye video; and finally, compressing coefficients of an iterated function system by a Huffman coding method, and if part of pixels of the block are within the video object area of the current code, and the other part of pixels are not within the video object area of the current code, processing a boundary block independently. The right channel is encoded by a MCP mode and a disparity compensation prediction (DCP) mode, the MCP is similar to the processing of the left eye, and the block with the minimum error is used as a prediction result. When the DCP coding mode is performed, the polarization and directionality in a three-dimensional parallel camera structure are utilized fully.

The invention provides a remote sensing image super resolution reconstruction method and a system based on a depth convolution network. The method comprises steps: a to-be-processed remote sensing image is converted to YCbCr space from RGB space, and brightness space and chromaticity space are separated; a multilayer depth convolution network is built, a super resolution reconstruction model is built based on the multilayer depth convolution network, the super resolution reconstruction model is used for reconstructing the brightness space, and brightness space after reconstruction is obtained; with the brightness space after reconstruction as a guide graph, the chromaticity space is guided for joint bilateral filtering, and chromaticity space after reconstruction is obtained; the brightness space after reconstruction and the chromaticity space after reconstruction are integrated, the to-be-processed remote sensing image after integration is returned to the RGB space from the YCbCr space, a super resolution image is obtained, and the super resolution image has a higher resolution than the to-be-processed remote sensing image. The above method and the system, in a condition of not relying on a multi-temporal remote sensing image sequence in the same scene, realize super resolution reconstruction in view of the remote sensing image, and the image resolution is enhanced.

An encoding apparatus for encoding a video signal includes: a prediction unit for generating a prediction block of a current block by using intra prediction or inter prediction; a residual data encoding unit for generating a residual block by using the current block and the prediction block, and transforming and quantizing the residual block; a residual data decoding unit for decoding a transformed and quantized residual block by inversely quantizing and inversely transforming the transformed and quantized residual block; and a deblocking filter unit for generating a reconstructed block by using a decoded residual block and the prediction block, and performing deblocking filtering, based on inter prediction information and intra prediction information of the reconstructed block and blocks neighboring the reconstructed block. The intra prediction information includes at least one of an intra prediction mode and an intra prediction block size.

Modify H.263-type quantization with an adaptive quantization parameter floor; this limits clipping of quantized DCT coefficients and consequent artifacts. The maximum absolute level of AC coefficients of a DCT transformed macroblock provides a minimum quantization parameter from integer division by 256 when the quantized levels are clipped to a range such as −127 to +127.

A method and system is provided for estimating the strength of block artifacts at each block boundary, based on global and local edge statistics computed from the input image (frame or field picture) in the spatial domain. Such a method systemically measures the strength of the compression artifacts that are associated with block-based compression / coding schemes such as JPEG, MPEG, and H.26x.

Disclosed are an encoding / decoding method relating to adaptive deblocking filtering, and an apparatus therefor. An image decoding method for performing an adaptive filtering in inter-prediction is provided. The method comprises the steps of: restoring, from a bitstream, an image signal including a reference block which is block-matched during inter-prediction of a current block to be decoded; obtaining, from the bitstream, a flag indicating whether or not the reference block exists in a current picture in which the current block is located; restoring the current block using the reference block; adaptively applying an in-loop filter to the restored current block on the basis of the obtained flag; and storing, in a decoded picture buffer (DPB), the current block to which the in-loop filter is applied or not applied.

The invention relates to a nuclear magnetic resonance image reconstruction method based on sparse representation and non-local similarity, and mainly aims to improve the reconstruction quality of a nuclear magnetic resonance image. The method comprises the following specific steps: firstly, sampling a Fourier transform coefficient corresponding to the nuclear magnetic resonance image by adopting a variable-density random down-sampling method, and performing Fourier inversion on sampled data to obtain an initial reference image for reconstructing; secondly, blocking the reference image to obtain similar structural characteristics of each type of image sub-blocks and obtain corresponding dictionaries of each type of image sub-blocks and sparse representation coefficients of the image sub-blocks; lastly, estimating the original image by using the non-local similarity of the image sub-blocks, restraining the sparse coefficients of the image sub-blocks, combining the sparsity of the image in a wavelet domain, and performing iterative reconstruction through a hybrid regular term solving model. By adopting the method, the non-local similarity of the image is fully utilized, complex textures in the image can be effectively reconstructed, and the quality of a reconstructed quality is improved.

The invention provides a frame rate improving method which mainly comprises four steps that image segmentation is carried out, and the foreground, the background and the object edge are obtained; the foreground and the background are subjected to variable size block matching motion estimation, and the object edge is subjected to motion estimation based on an optical flow field; a motion vector is subjected to post processing, and a proper motion vector is obtained; and a method of overlapped block motion compensation and bilinear interpolation is used for motion compensation, and interpolation frames are synthesized. According to the frame rate improving method, the problems that the halo effect, the edge block sawtooth effect and the like happen in a traditional frame rate improving method can be solved, and the method is widely used in the field of frame rate improving.

The invention discloses a frame frequency lifting method for combining target partition and irregular block compensation, which is characterized by comprising the following steps that: firstly, establishing a blank frame to be inserted; secondly, sampling a reference frame and the blank frame to be inserted; thirdly, calculating the frame difference between the reference frame and the blank frame to obtain a moving target outline and a moving target area mask by applying the morphological method; fourthly, partitioning the two reference frames into a target area and a background area; fifthly, moving and estimating subarea processing to obtain an initial motion vector; sixthly, smoothening the obtained initial motion vector; seventhly, trimming the initial motion vector after being smoothened to obtain a more accurate motion vector; eighthly, calculating the compensation weight coefficient Mu; ninthly, partitioning the block into a high relevant area and a low relevant area; tenthly, compensating subarea processing; and eleventhly, generating an interpolated frame. The method can be widely applied to the technical fields of video coding and encoding and video processing.

A system and method facilitating image retouching is provided. The invention includes an image retoucher having a boundary detector and an image extender. The invention provides for the image retoucher to extend care pixels of at least one of a foreground and a background near a detected spurious boundary by altering the binary mask used for compression of the foreground and / or the background.

A loop-filtering method for reducing quantization effect generated when an image data is encoded and decoded, and an apparatus therefor. The loop-filtering method includes the steps of extracting a flag indicating whether the image data requires loop-filtering using the distribution of inverse quantized coefficients (IQCs) of an inverse quantized image data and a motion vector indicating the difference between the previous frame and the current frame. The image data corresponding to the flag is then filtered by a predetermined method if the extracted flag indicates a need for the loop-filtering. Using the flags and an adaptive filter reduces the quantization effect and is useful to reduce the amount of computation required for the filtering. Also, the filtering can be performed through parallel processing without multiplication and division, so that the complexity of hardware can be reduced.

The invention provides a fractal-based binocular stereoscopic video compression and decompression method. In binocular stereoscopic video coding, a left channel is taken as a basic layer, a single motion compensation predictive mode (MCP) is adopted for coding, and the method comprises the following steps of: performing block DCT transformation coding on a left-eye start frame, performing motion estimation / compensation coding on a left-eye non-I frame, and calculating the pixel sum and the sum of squares of pixels of subblock domain and father block domain-related subblocks; searching the most similar matching block by using a full search method in a previous frame, namely a reference frame searching window of left-eye video; and finally compressing the coefficient of an iterated function system by using a Huffman coding method. A right channel is taken as an enhancement layer, the MCP and a parallax compensation predictive mode (DCP) are adopted for coding, and the lowest error is selected as a predicted result. During the DCP coding mode, the polalization and directionality in a stereoscopic parallel shooting structure are fully utilized; and the corresponding decompression process comprises the following steps of: for the left eye, decoding the start frame I by adopting a reverse DCT transformation mode, and performing Huffman decoding on the non-I frame so as to acquire the coefficient of the iterated function system; performing macrolbock-based decoding, calculating the pixel sum and the sum of squares of pixels of father block domain-related subblocks in the previous frame; and for a right eye, calculating the pixel sum and the sum of squares of pixels of the father block domain-related subblocks in the right-eye previous frame and a left-eye corresponding frame.

An apparatus and method which includes estimating a motion vector of a frame and / or field to be interpolated and the accuracy of the motion vector using motion vectors of previous and next frames and / or fields; determining motion information by analyzing the estimated motion vector, and calculating a correlation between the motion vector of the current block and the motion vectors of neighboring blocks; generating pixels to be interpolated by performing motion compensation in a frame and / or field to be interpolated using the estimated motion vector and using pixels neighboring a pixel to be interpolated in the frame and / or field to be interpolated and pixels neighboring a pixel to be interpolated in the previous and next frame and / or field of the pixel to be interpolated; and outputting the generated pixels as interpolation values according to the accuracy of the estimated motion vector, the motion information, and the correlation.

The invention relates to a method and an apparatus for reducing blocking artifacts in block-wise coding of still and video images. A learning filter generator is provided at the image encoder for generating a set of filters and associated filtering rules for filtering cross-boundary image patterns based on representative original and decoded training images using a supervised machine learning algorithm. An adaptive filter at the image decoder receives the generated filters and associated filtering rules and performs locally adaptive filtering in accordance with the received filtering rules.

The method implements an update step which is a selection among at least the following coding modes:a default coding mode which doesn't use the motion compensation for the calculation of the pixel if the pixel is not connected or which performs a low pass motion compensated temporal filtering of picture H of same level if the pixel is connected,an update_MV coding mode which performs a low pass motion compensated temporal filtering of picture H of same level according to a default motion vector calculated by taking into account motion vectors belonging to regions or pixels in the vicinity of the pixel to be calculated.Applications relate to video compression for transmission or storage of data.

The invention relates to a color image encryption method based on Latin square scrambling. Plaintext keys r1, g1 and b1 are calculated through utilization of R, G and B components of a color plaintextimage, an initial value and a parameter obtained through calculation based on the keys are substituted into a chaotic system, and three groups of chaotic sequences are generated; the chaotic sequences for scrambling and diffusion are selected through utilization of a chaotic sequence selection mechanism based on the plaintext and digital arrangement; and a final ciphertext image is obtained through adoption of a block scrambling policy based on a Latin square and the chaotic sequences, and diffusion operation based on the plaintext and a scrambled image. The encryption method is closely related to the plaintext, so the plaintext attack resistance is improved. The employed chaotic system is an improved chaotic system, a chaotic characteristic is good, the randomness is high and a key spaceis great, so a security level is further improved. A simulation result and safety analysis show that according to the encryption provided by the invention, an image complete encryption demand can besatisfied, the encryption efficiency is high, and the robustness is high.

The invention provides a fractal-based video compression and decompression method. The compression method is a novel video compression and encoding method which adopts the fractal iteration principle for video encoding, and comprises the following steps: encoding a starting frame through block-DCT transformation, and carrying out block motion estimation / compensation coding for a non-I frame, which comprises calculating the sum and sum of squares of the pixels of sub-blocks related to sub-block domains and parent-block domains, finding a most similar matching block in a previous frame search window through full search, and finally compressing factors of an iteration function system through Huffman encoding. The corresponding decompression method comprises the following steps: decoding the I frame through anti-DCT transformation, carrying out Huffman decoding for the non-I frame to obtain the factors of the iteration function system, and carrying out macroblock-based decoding, which comprises calculating the sum and sum of squares of the pixels of the sub-blocks relevant to the parent-block domains, and decoding the macroblocks in the current frame in sequence. The method improves the traditional method of fractal video compression, and not only greatly increases the compression ratio and the peak signal-noise ratio, but also improves the encoding speed, thereby enhancing the fractal video compression and decoding performance, and making the fractal video compression and decoding more practical.

The invention relates to an HDR and SDR self-adaptive code rate control method comprising the steps of judging whether an Meta Data code in an HDR video coding data of an HDR video coder changes; if yes, converting an HDR video code into an SDR video code or converting the SDR video code into the HDR video code; and if no, judging that a video in the current HDR video coder is an HDR video, and performing HDR video coding by the HDR video coder. According to the method provided by the invention, changing situations of a brightness rage and a chroma format of the video are firstly detected, scene change in the video is judged, mutual change of HDR and SDR is performed, and a distributed target code rate is adjusted, so that details in an highlight area and a black area in the HDR are more completely stored, meanwhile unnecessary code rate overhead in the SDR is reduced, and subjective code quality is improved; furthermore, the target code rate is adjusted at the area with large brightness change in the HDR code, and thus great quality improvement is achieved in partial areas.

The invention discloses an object and fractal-based multi-ocular three-dimensional video compressing and decompressing method. In multi-ocular three-dimensional video encoding, a middle ocular video is selected as a reference ocular video and is compressed by using a motion compensation prediction (MCP) principle; and other ocular videos are compressed by using a disparity compensation prediction (DCP)+MCP-based principle. Taking a trinocular video as an example, the middle ocular video is selected as the reference ocular video and is encoded by using a single MCP mode principle, wherein the method comprises the following steps of: first, acquiring a video object segmentation plane, namely an Alpha plane, by a video segmentation method, encoding a start frame by adopting discrete cosine transform (DCT), and performing block motion estimation / compensation encoding on a non-I frame; then, judging the area attribute of an image block by utilizing the Alpha plane, if the block is not in a currently encoded video object area, then not processing the external block, and if all of the block is in the currently encoded video object area, searching a most similar matching block in a reference frame of a previous frame, namely the middle ocular video, by a full search method; and finally, compressing coefficients of an iteration function system by utilizing a Huffman encoding method, if part pixels of the block are in the currently encoded video object area while part pixels are not in the currently encoded video object area, independently processing a boundary block. A left ocular video and a right ocular video are respectively encoded by adopting the MCP+DCP mode; and when the DCP encoding mode is performed, the polarization and the direction in a three-dimensional parallel camera structure are fully utilized.