419 results about "Data compression ratio" patented technology

A data compression program making a computer perform processing which enables compression of only highly compressible data. First, a transmitter-side device performs compression processing of a portion of data to be compressed. Next, the transmitter-side device compares volumes of the portion of the data before and after the compression processing, and determines whether or not the compression processing is effective. When the data to be compressed is uncompressed data, the volume of the portion of the data is reduced by the compression processing. On the other hand, when the data to be compressed is compressed data, the volume of the portion of the data is not reduced by the compression processing. Therefore, only when it is determined that the compression processing is effective, the transmitter-side device compresses the other portions of the data to be compressed.

A hardware accelerator for improving the decompression performance when decompressing data in Lempel-Ziv-Huffman compressed data format. The use of a Huffman encoding second stage in the popular and widely-used Lempel-Ziv-Huffman standard improves the compression ratio but complicates the decompression, because the Huffman encoding is applied selectively only to certain parts of the Lempel-Ziv tokens, and thus Huffman decoding must also be applied selectively during decompression. The present invention features a variable-length token decoder which is able to selectively decode the Huffman-encoded portions of the compressed data, and therefore enables high-performance decompression for compressed data having a very good compression ratio. Such an accelerator is well-suited for use in data processors which are to be loaded with pre-compressed data and software applications, particularly those employing flash memory.

The invention discloses a data parallelism compression method. The data parallelism compression method comprises the step of reading, namely, data to be compressed are read from a memory device through an I/O, the step of segmenting, namely, data to be compressed are evenly segmented into N data blocks which are stored in an input buffering area corresponding to each data block, the step of compressing and encoding, namely, processes control the data blocks in the corresponding input buffering areas, the data blocks are compressed and encoded through a multithreading method, and the data which are compressed and encoded are stored in an output buffering area, and the step of writing, the data which are compressed and encoded in all processes in the output buffering area are merged, and the merged data are written to an output file. According to the data parallelism compression method, an ideal compression ratio is obtained, time for compressing is greatly shortened, the data parallelism compression method can be well applied to a cloud storage or database system, the problem of low compression timeliness is solved, and whole performance of compression is improved.

A video encoding/decoding system based on 3D wavelet decomposition and the human perceptual model is implemented. JND is applied in quantizer design to improve the subjective quality of compressed video. The 3D wavelet decomposition helps to remove spatial and temporal redundancy and provides scalability of video quality. In order to conceal the errors that may, occur under bad wireless channel conditions, a slicing method and a joint source channel coding scenario, that combines RCPC with CRC and utilizes the distortion information to allocate convolutional coding rates are proposed. A new subjective quality index based on JND is presented and used to evaluate the overall system performance at different signal to noise rations (SNR) and at different compression ratios. Due to the wide use of arithmetic coding (AC) in data compression, it is considered as a readily available unit in the video codec system for broadcasting. A new scheme for conditional access (CA) sub-system is designed based on the compression graphic property of arithmetic coding. Its performance is analyzed along with its application in a multi-resolution video compression system. This scheme simplifies the conditional access sub-system and provides satisfactory system reliability.

A data storage subsystem having a plurality of data compression engines configured to compress data, each having a different compression algorithm. A data handling system is configured to select at least one sample of data; operate a plurality of the data compression engines to compress the selected sample(s); determine the compression ratios of the operated data compression engines with respect to the selected sample(s); and select the data compression engine having the greatest compression ratio with respect to the selected sample(s), to compress the data. Further, the data compression engines may be in tiers from low to high in accordance with expected latency to compress data and to uncompress compressed data; and a data compression engine is selected from a tier that is inverse to the present rate of access.

A method and apparatus for compressing a mixed raster content image that represents a color or gray scale a document is disclosed. The pixel map is decomposed into a three-plane representation--a reduced-resolution "upper" plane, a reduced-resolution "lower" plane, and a high-resolution binary selector plane. An iterative smoothing technique is then used to pre-process the upper and lower planes using the information contained in the selector plane, thereby reducing the amount of data that will be subjected to further processing.

The invention discloses a flash translation layer (FTL) with a data compression function and an implementation method. The FTL with the data compression function mainly comprises a compressor, a decompressor, a buffer, an address mapping management module, a trash recycling module and a loss balancing module. An LZ77 (Lempel-Ziv 77) algorithm based single-page compression strategy is adopted for the compression of written-in data and the decompression of readout data. A data compression technology is used for decompressing/compressing the readout/written-in data, a soft buffer is implemented in the FTL, and the data volume written-in and read-out from a flash memory solid state disk each time is reduced, thereby improving the integral reading and writing performance of the flash memory solid state disk.

The invention discloses a universal remote control method, which is characterized by comprising the following steps of: identifying infrared remote control signals of each piece of equipment to acquire primary data, compressing infrared codes in the primary data by using a compression method, storing the compressed infrared codes in a primary data sheet, and when the infrared codes are used, performing decompression reduction to control given infrared remote control equipment to work. By the compression method used by the universal remote control method, a data volume can be reduced to be within 1K by compression, and the highest compression ratio of 16:1 can be realized, thereby reducing a storage space required by the learning of a remote controller code to further make possible all remote controller code learning of a remote controller.

When compressing an arrangement of fixed-length records in a columnar direction, a data compression device carries out data compression aligned with the performance of a data decompression device by computing a number of rows processed with one columnar compression from the performance on the decompression device side, such as the memory cache capacity of the decompression device or the capacity of a primary storage device which may be used by an application, and the size of one record. Thus, while improving compression ratios of large volumes of data, including an alignment of a plurality of fixed-length records, decompression performance is improved.

The invention relates to a Bayer image compression method based on YUV conversion, which belongs to the technical field of an aerospace optical remote sensor and is a Bayer image compression method used for an aerospace optical remote sensing CMOS camera. The method comprises the following steps: carrying out space conversion on a Bayer-format image from a three-color space to a brightness-chroma space, eliminating the relativity among the three color components to be ready for different compression ratios used by brightness and chroma, self-adaptively determining the compression ratios based on the complexity of the image, carrying out line conversion and encoding. The invention greatly improves the quality of the compressed image by carrying out space conversion to eliminate the relativity among the three color components, and further enhances the adaptive capacity of the camera by using different compression ratios for images of different complexities.

This invention relates to a method and apparatus for controlling image quality and compression ratios in image segmentation. More particularly, the invention is directed to an image segmenting system and method that analyzes and classifies pixel blocks of an image to determine the manner in which the image block should be compressed, e.g. with a lossy or a lossless technique. This approach, which assumes no apriori knowledge of the any specific region of the image, results in effective use of the various known compression techniques and provides improved overall compression ratios and image quality.

A moving image processing device (200) includes a face detector (3) (specific target detector), a compression ratio controller (4), and a quantizer (9) (video compressor). The face detector (3) detects a person's face included in an input image and extracts a face region. The compression ratio controller (4) generates and outputs a compression control instruction for reducing the compression ratio of the face region extracted by the face detector (3) so that a degree of reduction in the compression ratio of the face region is small in the case where the ratio of the area of the face region to the entire area of the input image is relatively large and so that the degree of reduction in the compression ratio of the face region large in the case where the ratio of the area of the face region to the entire area of the input image is relatively small. The quantizer (9) performs a quantization processing of the face region according to the compression control instruction given from the compression ratio controller (4).

The invention discloses an embedded system data compression and decompression method based on BP neural network, which comprises the following steps: 1). Choice of the type of neural network; 2). The structure of the mapping relation; 3). Data compression of each standard string on a PC based on BP neural network; 4). Data decompression in the embedded system based on BP neural network; 5). To write the standard strings get from decompression in decompressed data file in turn; 6). To delete all special characters occurring at the end of the file. The invention has the advantages of simulating the mapping relation between line code and line data using neural network, meeting the purpose of data compression through using the information occupying less signal space to express the information occupying more signal space, breaking through the limit of traditionally only depending upon coding to lower data redundancy, realizing higher compression ratio, repeating multiple data compression to reach satisfactory compression ratio, effectively compressing compressed data with entropy coding and further improving compression effect.

[PROBLEMS] To improve the data compression ratio in the data compression/decompression method utilizing the down-sampling process. [MEANS FOR SOLVING PROBLEMS] Image data in a DS area division unit (130) is divided into a plenty of DS areas and DS areas which are not important are converted into contracted data of the block size by down-sampling in a down-sampling unit (131). A relocation unit (132) allocates two or more contracted data in one DS area, inserts file data into the other portion in the DS area, and removes the DS area where no contracted data is allocated, thereby reducing the entire image size. The image data thus contracted is inputted into a JPEG encoder (14) and subjected to a DCT process and a quantization process for each block. When performing restoration, decompression is performed by the JPEG decoder and the original location is restored. As for the contracted data, interpolation is performed to restore the image data.