75 results about "Lossy coding" patented technology

Compression of signal samples output from a parallel, time-interleaved analog to digital converter (TIADC) for a baseband signal, includes calculating first or higher order differences of consecutive signal samples followed by lossless or lossy encoding of the difference samples to produce compressed samples. Compression of a TIADC output signal with a nonzero center frequency, includes calculating sums or differences of pairs of signal samples separated by an appropriate number of sampling intervals followed by lossless or lossy encoding. The sums or differences of the signal samples have lower magnitudes than the original samples, allowing more efficient compression. Lossy compression alternatives produce compressed data with a fixed bit rate or with a fixed quality in the decompressed samples. Alternatives for lossy compression include attenuating the analog signal before sampling by the TIADC, applying bit shifters or multipliers after sampling to reduce the magnitudes of the signal samples, and lossy encoding.

A configuration for encoding and decoding the data is disclosed herein. A server retrieves webpage content to filter and extract text and image data. The text data is encoded using a lossless encoder, whereas the image data is downsampled to a lower resolution and encoded using a lossy encoder. The encoded text and image data is transmitted over a network. Once the encoded data is received on the client device, the text and image data is decoded using an inverse encoding algorithm and resized at a resolution appropriate to the native resolution of the display device.

The embodiment of the invention provides an image transmission method and device for a remote desktop. The method includes the following steps that: format type recognition is performed on a source data to be transmitted; when the source data are recognized as image-format data, coding processing is performed on the image-format data through adopting a lossy coding technique; and data code streams which have been subjected to the coding processing are transmitted to a client end. According to the image transmission method and device for the remote desktop, the format type recognition is performed on the source data to be transmitted before the coding processing, and different processing is performed according to source data of different format types, when the source data are recognized as the image-format data, and the coding processing is performed on the image-format data through adopting the lossy coding technique, and the data code streams which have been subjected to the coding processing are transmitted to the client end, and therefore, compression ratio can be improved, so transmission efficiency can be also improved, and transmission delay can be reduced.

Lossless and lossy codes are combined for data compression. In one embodiment, the most significant bits of each value are losslessly coded along with a lossy version of the original data. Upon decompression, the lossless reduced-precision values establish absolute bounds for the lossy code. Another embodiment losslessly codes the leading bits while trailing bits undergo lossy coding. Upon decompression, the two codes are summed. The method preserves edges and other sharp transitions for superior lossy compression. Additionally, the method enables description-length inference using noisy data.

According to this invention, encoded data of a target data amount is generated by one image input operation while both lossless encoding and lossy encoding are adopted. For this purpose, an encoding sequence control unit controls a first encoding unit for lossy (JPEG) encoding, a second encoding unit for lossless (JPEG-LS) encoding, first and second memories, and a re-encoding unit, and stores, in a first memory, encoded data of a target data amount or less that contains both losslessly and lossily encoded data. A correction unit corrects, of encoded data stored in the first memory, encoded data of an isolated type to the type of neighboring encoded data, and outputs the corrected data.

The invention discloses a coding optimization method and a coding optimization device for images. The images are partitioned into blocks; each block is analyzed so as to select a proper coding mode for each block; for areas suitable for lossless coding, the areas are coded in a lossless coding mode; and for areas suitable for lossy coding, the areas are coded in a lossy coding mode; therefore, in spite of types of the images, the optimal image quality and the least data quantity can be achieved always.

According to this invention, encoded data of a target data amount can be generated by one image input operation while both lossless encoding and lossy encoding are adopted. For this purpose, a first encoding unit which generates lossy encoded data, a second encoding unit which generates lossless encoded data, and an attribute determination unit which detects the number of colors in a pixel block to be encoded parallel-process the same pixel block. When the number of colors in the pixel block of interest is equal to or smaller than a predetermined number, an encoding sequence control unit stores lossless encoded data in a first memory. When the number of colors exceeds the predetermined number, the encoding sequence control unit stores encoded data of a shorter code length among lossy encoded data and lossless encoded data in the first memory.

The present invention refers to low code rate screen encoding method, belonging to video coding decoding technology field. It contains collecting computer screen picture; uniformly dividing screen picture into plurality of image pieces; comparing with previous frame screen picture corresponded piece; according to comparative result determining whether to make space domain resolution ratio reducing and encoding to current frame, if encoding then adopting time domain self adaptation key frame interval method to determine encoding as key frame or non-key frame; respectively processing mouse messages and image data, adopting destructive and non destructive encoding adjoined encoding method to image data. The present invention is suitable for low code rate videoconference, tele education, and long-range control etc.

A scalable lossless audio coding/decoding apparatus and method are provided. The scalable lossless audio coding apparatus includes a lossy coding unit which lossy codes an input audio signal and generates a lossy bitstream, a lossy signal regenerating unit which decodes the lossy bitstream, compares a decoded signal with the input audio signal, and regenerates a lossy signal that is lost when lossy coding is implemented, a lossless coding unit which lossless codes the lossy signal and generates the result of lossless coding as a lossless bitstream, and a multiplexing unit which multiplexes the lossy bitstream with the lossless bitstream and generates one output bitstream. The lossy-coded lossy bitstream is mixed with the lossless-coded lossless bitstream, thereby one output bitstream is generated and transmitted, and the lossy audio signal in which only the lossy bitstream is restored from the output bitstream or the lossless audio signal in which the lossy bitstream and the lossless bitstream are restored and mixed with each other can be selectively generated.

Techniques are described for coding residual data of a prediction residual block with transform skipping. A transform may be skipped for a residual block when the residual block is coded using either a lossless coding mode or a lossy coding mode in a transform skip mode. According to the techniques, based on a transform being skipped for a residual block, a rotation unit included in a video encoder or a video decoder determines whether to rotate the residual block prior to coding residual data of the residual block. In some examples, a rotation value may be explicitly signaled between the video encoder and the video decoder. In other examples, the video encoder and the video decoder may each independently determine whether to rotate the residual block based on a type of boundary at two or more edges of the residual block.

A method is described for packing variable-length entropy coded data into a fixed rate data stream along with resolution enhancement data, the method providing tightly constrained propagation of transmission channel errors and graceful degradation of signal resolution as entropy-coded data rate increases. An application to a multiband ADPCM audio codec is also described.

A method of efficient lossless mode syntax signaling for a coding system supporting both lossless and lossy coding is disclosed. In one embodiment, a first syntax element is incorporated in a picture level to indicate whether to use a forced lossless coding mode if lossless coding is allowed for the current picture. If the first syntax indicates that the forced lossless coding mode is selected, all coding units in the slices of the picture are coded using lossless coding. If the first syntax indicates that the forced lossless coding mode is not selected, each coding unit in a slice of the picture can be coded according to a second syntax element indicating whether each coding unit is coded using lossless coding or not. In another embodiment, the forced lossless mode can be applied to coding units on a slice by slice basis.

The invention discloses a coastal zone hyperspectral image distributed lossy coding and decoding method based on a region of interest, which belongs to the field of image processing. According to spectral correlation of the hyperspectral image, a spectral frame is divided into a plurality of spectral groups, and each spectral group comprises one key frame and a plurality of WZ frames; after region of interest extraction is carried out on the key frame of each spectral group, JPEG-LS lossless coding and decoding are carried out on the region of interest of the key frame, SPIHT-based coding and decoding are carried out on a background region, and compressed sensing-based coding and decoding are adopted for the WZ frames of each spectral group. The method of the invention has the advantages that the coding complexity is low, the error resilience is strong, the quality of a bit stream can be graded and the like.

The invention discloses an improved transformation coefficient sign data hiding (SDH) method based on a recovered transformation coefficient. The improved transformation coefficient sign data hiding method based on a recovered transformation coefficient adopts the parity of the sum of the amplitudes of the first non-zero transformation coefficient and the last non-zero transformation coefficient of a 4*4 transformation coefficient matrix CG to express the sign of the last non-zero transformation coefficient, thus obtaining a coefficient sign; and if the obtained coefficient sign does not accord with the practical coefficient sign, the amplitudes of two transformation coefficients are adjusted according to rate distortion optimization quantification (RDOQ) criteria. By adopting the method, the code of the last non-zero transformation coefficient sign in the CG can be omitted, so that the bit number of code sign data is reduced; the method can be compatible with the SDH technology, so that the loss of the SDH technology on video coding quality in lossy coding is relieved to a certain degree, and the coding performance is effectively improved; and the method is very low in complexity, and is applicable to various video resolutions.

Lossless compression algorithms can only exploit redundancies of the original audio signal to reduce the data rate, but not irrelevancies as identified by psycho-acoustics. Lossless audio coding schemes apply a filter or transform for decorrelation and then encode the transformed signal. The encoded bit stream comprises the parameters of the transform or filter, and the lossless representation of the transformed signal. However, in case of lossy based lossless coding the additional amount of information exceeds the amount of data for the base layer by a multiple of the base layer data amount. Therefore the additional data cannot be packed completely into the base layer data stream e.g. as ancillary data. The at least two data streams resulting from the combination of lossy coding format with a lossless coding extension are the base layer containing the lossy coding information and the enhancement data stream for rebuilding the mathematically lossless original input signal. Furthermore several intermediate quality layers are possible. However, these data streams are not independent from each other. Every higher layer depends on the lower layers and can only be reasonably decoded in combination with these lower layers. According to the invention, a special combination of one-time header information with repeated header information in a block structure is used, which kind of combination depends on the type of application. Assignment information data identify the different parts or layers of the lossless format belonging to one input signal. Synchronisation data are used to combine the different data streams or parts or layers to a single lossless or intermediate output signal. These features are used in a file format and in a streaming format.

The invention discloses a data compression method and device and a data encoding/decoding method and device, and the method comprises the steps: carrying out the classification of to-be-processed coding blocks before the coding, carrying out the lossy coding or lossless coding of different types of to-be-processed coding blocks, and meeting the requirement for reducing the occupation of transmission bandwidth; moreover, the decoding end performs necessary color compensation on the decoded data of the code stream subjected to lossy coding by using the chrominance information, so that the fidelity of the transmitted data is ensured.

Disclosed herein is a method for acceleration of video encoding owing to adaptive discarding macroblocks is based on objective regularities between numerical characteristics used on successive stages of lossy encoding process. This method enables to avoid a large amount of computation and transformation being not necessary due to the fact that their results would be reduced to zero on stage of quantization. The early revelation of these regularities and adaptive control of discarding technique produce a very effective encoding scheme that can be used in the encoding systems that are aimed to extremely fast processing of video streams, in particular, in multi-channel codecs.

In lossy based lossless coding a PCM audio signal passes through a lossy encoder (41) to a lossy decoder (42). The lossy encoder provides a lossy bit stream. The difference signal (SDiff) between the PCM signal and the lossy decoder output is lossless encoded (52), providing an extension bit stream. The invention facilitates enhancing a lossy percep tual audio encoding/decoding by an extension that enables mathematically exact reproduction of the original waveform using enhanced de-correlation, and provides additional data for reconstructing at decoder site an intermediate-quality audio signal. The lossless extension can be used to extend the widely used mp3 encoding/decoding to lossless encoding/decoding and superior quality mp3 encoding/decoding.

The invention discloses a QR code watermark image data compression and coding method, and the method comprises the steps: carrying out the decomposition of a QR watermark image through combining with the symbol structure features of a QR code after DWT transformation and compression, and extracting data and an error correcting code part therein; rearranging the data and an error correcting code in a one-dimensional binary watermark information sequence, and hen carrying out the compression and coding of the watermark information sequence through employing an improved jump block coding mechanism; finally enabling a binary sequence generated after compression and coding to serve as the watermark information embedding carrier data. The method employs the coding mechanism and structure features of the QR code to solve a problem of data compression of a QR code watermark image. The method gives the play to the strong capability of error correction of the QR code, employs the lossless coding and loss coding mechanisms in the compression and coding process, reduces the data size, and also guarantees that a compressed code can be normally decoded and recognized. After compression and coding, the binary sequence, compared with an original QR code watermark image, is higher in data compression ratio, and can meet the requirements of a small-data-size watermark information carrier for the size of embedded data.