102 results about "Bit plane coding" patented technology

Digitalized video images are compressed in several steps in order to provide a system for transmitting moving video pictures via narrow band channels, such as the telephone network. The system is based on any extension of the bit-plane coding technique to video sequences and lossy conditions. The compression technique can also be advantageously used in a lossless compression system. The system involves the steps of bit plane representation and skipping the least significant bit plane(s), shifting the pixels, coding with a Gray code, the use of segmentation, and motion-estimation/motion compensation and application of a transmit/not transmit/motion compensate (TX/NT/MC) procedure, exploiting of the temporal redundancy of two corresponding bit planes via an XOR operation on two successive images, and a plane-by-plane application of an extended RLEID technique. The RLEID technique includes coding a run of like binary symbols with one word, the run including a transition between the penultimate and ultimate binary symbol.

In one aspect, for a first interlaced video frame in a video sequence, a decoder decodes a bitplane signaled at frame layer for the first interlaced video frame. The bitplane represents field/frame transform types for plural macroblocks of the first interlaced video frame. For a second interlaced video frame in the video sequence, for each of at least one but not all of plural macroblocks of the second interlaced video frame, the decoder processes a per macroblock field/frame transform type bit signaled at macroblock layer. An encoder performs corresponding encoding.

An encoder sends binary information indicating whether a prediction mode is forward or not-forward for one or more macroblocks in an interlaced B-field. For example, the encoder sends forward/not-forward decision information at B-field level in a compressed bitplane. Sending forward/not-forward prediction mode decision information in a compressed bitplane at B-field level can reduce coding overhead for prediction mode coding. A decoder performs corresponding decoding.

A method for encoding a digital signal into a scalable bitstream comprising quantizing the digital signal, and encoding the quantized signal to form a core-layer bitstream, performing an error mapping based on the digital signal and the core-layer bitstream to remove information that has been encoded into the core-layer bitstream, resulting in an error signal, bit-plane coding the error signal based on perceptual information of the digital signal, resulting in an enhancement-layer bitstream, wherein the perceptual information of the digital signal is determined using a perceptual model, and multiplexing the core-layer bitstream and the enhancement-layer bitstream, thereby generating the scalable bitstream. A method for decoding a scalable bitstream into a digital signal comprising de-multiplexing the scalable bitstream into a core-layer bitstream and an enhancement-layer bitstream, decoding and de-quantizing the core-layer bitstream to generate a core-layer signal, bit-plane decoding the enhancement-layer bitstream based on perceptual information of the digital signal, and performing an error mapping based on the bit-plane decoded enhancement-layer bitstream and the de-quantized core-layer signal, resulting in an reconstructed transformed signal, wherein the reconstructed transformed signal is the digital signal.

An image processing apparatus includes an encoding section and a decoding section. The encoding section includes means for encoding an input image to generate encoded data, means for receiving a designation of an image quality for display of the input image, and means for outputting, of the encoded data, encoded data necessary to display the input image at an image quality equal to or higher than the designated image quality. The decoding section includes means for decoding the encoded data output from the encoding section to generate image data, and means for, when an image based on the image data has an image quality higher than the designated image quality, converting the image data into image data having the designated image quality.

The disclosure relates to a method for performing context based binary arithmetic coding with a stochastic bit-reshuffling scheme in order to improve MPEG-4 fine granularity scalability (FGS) based bit-plane coding. The method comprises steps of: replacing 8×8 DCT with 4×4 integer transform coefficient in MPEG-4 AVC (Advance Video-Coding); partitioning each transform coefficient into significant bit and refinement bit; setting up significant bit context based on energy distribution within a transform block and spatial correlation in adjacent blocks; using an estimated Laplacian distribution to derive coding probability for the refinement bit; and using the context across bit-planes to partition each significant bit-plane for saving side information bit.

An apparatus and method for performing bitplane coding with reordering, that may be used in a Fine Granularity Scalability (FGS) system. The apparatus and method reorder coefficients each time after a bitplane is coded. By reordering, the apparatus and method separate the coefficients into two groups. When coding a bitplane, bits in the first group are copied into the bitstream, while the bits in the second group are subject to common run-length, VLC, or arithmetic coding. The apparatus and method may also be used with or in a conventional SNR, temporal and/or spatially scalable architectures, for example, as utilized within an MPEG-4 framework.

In one aspect, an encoder/decoder selects a bitplane mode from a group of plural available bitplane modes, and processes a bitplane according to the selected bitplane mode, wherein the bitplane indicates AC prediction status information for plural macroblocks of a video picture. In another aspect, an encoder encodes a bitplane that indicates AC prediction status information for plural macroblocks of a video picture and signals the encoded bitplane. In another aspect, a decoder receives an encoded bitplane and decodes the bitplane, wherein the bitplane indicates AC prediction status information for plural macroblocks of a video picture.

In wavelet-based image compression schemes, a very sparse representation of the image signal may be obtained after quantization to transform coefficients. In addition, the nonzero coefficients 2-dimensionally cluster around the edge or texture areas. In existing systems, for example JPEG2000, in the bit-plane coding process, coefficients are repeatedly scanned and encoded in a 1-dimensional pattern within code-blocks. A large number of zeros have to be encoded to record the distribution of significant coefficients. It inevitably causes a big loss of compression performance. Quaternary reaching method emphasizes reaching and encoding the significant coefficients in 2-dimensional pattern. It fully adapts to the 2-dimensional character of the significance distribution of quantized coefficients. Besides, it admits very economical implementation. The recording of redundant information is drastically reduced. As result, it magnificently enhances both compression performance and computation performance against existing systems.

A decoder decodes skipped macroblocks of an interlaced frame. Skipped macroblocks use exactly one motion vector and have no motion vector differential information, and lack residual information. The skipped macroblock signal indicates one-motion-vector coding. The skipped macroblock signal can be a compressed bitplane (in a selected bitplane coding mode) sent at frame layer in a bitstream, or an individual bit sent at macroblock layer. In another aspect, an encoder jointly encodes motion compensation type and field/frame coding type for a macroblock in an interlaced P-frame. The encoder also can jointly encode other information for the macroblock (e.g., the presence of a differential motion vector). A decoder decodes a joint code (e.g., a variable length code in a variable length code table) to obtain both motion compensation type and field/frame coding type (and potentially other information) for the macroblock.

The invention relates to a high capacity information hiding method using JPEG2000 compressing images as the carrier. The operation steps are: applying wavelet decomposition, wavelet coefficients quantification and bit-plane coding to images, and determining the truncation position of the code flow of all coding blocks and the lowest bit-plane of the embeddable information by rate-distortion optimization; primarily choosing a wavelet coefficient which is more than the threshold value as the embedding point, and making a redundancy estimation and adjusting the embedding point and the embedding strength; embedding the synchronous information and the hidden information into the quantified wavelet coefficient in an order of the bit plane from the lowest to the highest starting from the lowest embeddable bit-plane; making a second bit-plane coding and organizing the code flow after embedding the information. The high capacity information hiding method is based on a second coding strategy to determine the embedding position and improves the information hiding volume by self-adaptively choosing the embedding point and adjusting the embedding strength, The high capacity information hiding method has the advantages of being transparent completely for the standard JPEG2000 decoders and being able to be conveniently integrated in the JPEG2000 coders. Meanwhile, the code flow still can decode normally after being embedded with hiding information.

A method and an apparatus for encoding/decoding an audio signal by using bandwidth expansion technique are provided to output an encoded bitplane and encoded bandwidth expansion information as an encoded result of an input signal, thereby efficiently encoding high frequency components at a limited bit rate and accordingly improving sound quality. An audio signal encoding method comprises the following steps of: splitting an input signal into a high band signal and a low band signal(1300); converting each of the high and low band signals from a time domain to a frequency domain(1310); performing quantization and context-dependent bitplane encoding of the converted low band signal(1320); generating and encoding bandwidth expansion information showing a characteristic of the converted high band signal by using the converted low band signal(1330); and outputting the encoded bitplane and the encoded bandwidth expansion information as an encoded result of the input signal(1340).

A source encoder encodes audio signals into increasing quality layers defined in bit planes. Each bit plane has a data unit that includes a beginning partition having one or more contiguous refinement bits, a second partition having one or more contiguous coded significance bits, a third partition having one or more contiguous sign boundary mark bits, and a fourth partition having one or more contiguous coded sign bits. A channel encoder encodes the bit planes into respective columns containing multiple rows. Unequal error protection coding is provided according to the quality of each layer such that each row has row and column channel protection codes for the respective row and column that correspond to the respective quality layer. For the corresponding row and column, each row contains the row channel protection codes and either the compressed audio data from the respective layer or the column channel protection codes. A server machine can use a network feedback transmission to allocate bits to the source encoder and the channel encoder.

A method and system for encoding an image for providing encoded data for transmission or storage. After the image is decomposed by a transform into sub-bands containing blocks or samples of transformed image data organized in a number of bit-planes, it is adjusted to reduce the number of bit-planes prior to being encoded by a bit-plane coder into encoded data. The reduction of the bit-planes is based on the compression factor of the encoding process, the transmission target bit-rate, the type of sub-band and the resolution level of the transformed image data.

The invention discloses an image transmission method, an image transmission device and an image transmission system. The method comprises the steps of determining a bit plane code quantity of an original target image according to the current network state of a transmission network, wherein the original target image is an image to be transmitted; coding bit plane information of the bit plane code quantity, thus acquiring a coded code stream; and transmitting the coded code stream. According to the method, the device and the system provided by the invention, the technical problem that in the prior art, video data occupies relatively large bandwidth when in transmission, and thus the requirement on network bandwidth is relatively high is solved.

An bit-plane coding pass generator is provided in which for SP-pass processing quantization coefficient of each code block divided into bit planes, “significant (S)” or “non-significant (N)” data in a predetermined area and those around the area and compared with an S/N matching pattern. The S/N matching pattern has been set when a jump can be made from an arbitrary sample point to a next sample point to be processed by SP pass. The jump is made to the next sample point to be processed by SP pass according to a jump address value obtained from a pattern coincident with a current S/N matching pattern. Thus, by reducing the time for the significant propagation (SP) pass defined in JPEG-2000, a code block can be coded at a higher speed by three coding passes.

A coefficient labeling circuit arrangement for bitplane coding passes in embedded block coding. In one embodiment, a significance lookahead circuit generates lookahead significance states of coefficients in past, current, and future magnitude stripe slices of a code-block containing a plurality of coefficients. A plurality of context labeling circuits are coupled in parallel to the significance lookahead circuit. Each context labeling circuit is configured with a respective significance propagation pass circuit, a respective magnitude refinement pass circuit, and a respective cleanup pass circuit. Context labels are generated in parallel for all bits of the current magnitude stripe slice.

A picture-encoding apparatus provided by the present invention includes a wavelet transformation unit for carrying out wavelet transformation on an input picture to generate wavelet-transformation coefficients, a bit-plane encoding-pass-generating unit for spreading the wavelet-transformation coefficients over bit-planes, an arithmetic encoding unit for carrying out an arithmetic encoding process in an encoding pass, a rate control unit for controlling an encoded-data quantity of the generated arithmetic code so as to achieve a target encoded-data quantity, a header-generating unit for generating a header, a packet-generating unit for generating a packet by addition of the header to the arithmetic code experiencing control of the encoded-data quantity executed by the rate control unit, and an encoded-code-stream-truncating means for truncating an encoded-code stream completing processing through all the encoding passes by discarding a rear portion of the stream so as to make an encoded-data quantity of the stream equal to a target encoded-data quantity.

An image compressing apparatus divides an image into plural tiles, decomposes each tile into plural sub band by frequency conversion, and conducts bit plane encoding of each sub band for each encoding unit, wherein the image compressing apparatus includes a code discarding unit selectively discarding a code obtained by the bit plane encoding for each encoding unit, and wherein the code discarding unit includes a discard amount setting unit that makes generally even the amount of code discarding in the encoding units that are in mutually adjacent relationship across a tile boundary.

The invention discloses a lossless compression method of curve vector data based on integer wavelet transformation and bit plane coding. In the invention, the integer wavelet transformation is introduced in a vector data compression algorithm. The integer wavelet transformation can compress the majority of energy of the data in a low-frequency coefficient and only the minority of energy in a high-frequency coefficient. In the invention, the low-frequency coefficient is coded by using the Huffman coding scheme and the high-frequency coefficient is coded by using a plane coding scheme. The embedded coding of the vector data can be achieved by the bit plane coding. The designed bit plane coder can sequence the bit streams to be coded according to the different importance, and the coding is finished at any time according to the requirements of a target code rate or a degree of distortion. Similarly, a given code stream decoder can finish decoding at any time, and the reconstruction vector curve of the target code rate at a corresponding place where the code stream is cut off can be obtained. Experiments show that the compression scheme achieves the embedded coding of the vector data, can progressively transmit and display the compressed code streams of the vector data, and simultaneously obtains a relatively high lossless compression ratio.

The invention discloses a method for effectively encoding and decoding a JPEG2000 image based on a vision potential attention target area. The method comprises the following steps of: before the image is encoded, dividing the image into a plurality of Tile blocks based on the potential target area of different attentions and pre-assigning corresponding target code rates according to vision potential attention target area extraction technology; and then carrying out code stream organization and packaging to realize image compression through quantization, adaptive wavelet transformation, and a bit plane encoding and arithmetic encoder code word reset mechanism on the basis of potential attention target area quality layer code rate control. When network band width is insufficient, the image reconstruction quality of a more-concerned target area can be exchanged at the expense of part of code rates of the target area with smaller potential attention; simultaneously, retractable high-efficiency image encoding and decoding technology is combined with a qualified content based on the potential attention target area.

A novel method for coding and decoding video data and codec thereof are disclosed. The invented method provides an FGS (fine grained scalability) algorithm using bit plane coding technique. While conducting the bit plane encoding, the spatial and temporal dependence between bit planes is used to exploit the redundancy in the bit planes. In the embodiment of this invention, the bit plains are represented by quadtrees and bit plane prediction is made to remove the spatial and temporal redundancy in a video. The scalability of the video data is fine grained since atoms of the motion residuals do not have to be grouped as coding units.