35 results about "Jpeg2000 compression" patented technology

An interactive medical image communications and display method which is based on JPEG2000 compressed data package transmission; the method uses the superior performance of JPEG 2000 compressed algorithm, and with the method, the JPEG 2000 compression process is implemented on the medical image in the pattern based on subsections; in this way, only the partial data package corresponding to image windows which client terminal is interested in rather than the entire image data is transmitted under the client/server environment and the client terminal could extract and display the medical image interactively based on the image content according to requests. With the invention, high-resolution DICOM medical image can be transmitted and displayed in real time fast and efficiently through WAN even when the bandwidth is limited to realize fast share of medical image information between PACS systems in different areas and hospitals; with the invention, medical resource can be effectively utilized, and the medical treatment effect, quality and efficiency of clinic activities such as long-distance consultation can be promoted.

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.

The system transmits High Definition (HD) video/audio data, e.g. a JPEG2000-compressed video stream multi-channel audio stream, over a packet switching network, e.g. an Ethernet or IP network. Both the transmitter unit VTB and the receiver unit VRB feature a modular structure consisting of a base module or baseboard common to both units and one or more exchangeable adapter cards attached to or inserted into the baseboards to perform selected functions. The basebord is unitary, i.e. identical for both the VTB and the VRB; its components are activated depending upon the baseboard being in a VTB or a VRB. Each card is unique and earmarked and serves a specific purpose, e.g. for video coding and decoding, SMPTE processing, clocking/re-clocking, audio embedding/extraction. Upon inserting a card into a baseboard, the earmark is identified and the baseboard configured as transmitter or receiver baseboard. Functions in the baseboard can be implemented in Field Programmable Gate Arrays (FPGAs) and the network management, configuration, and/or control of the transmitting and/or receiving processes be performed by a softcore processors. This inventive combination of modular hardware/software results in a cost-effective, reliable, and fast system for transmitting large data volumes over packet switching networks.

A method for producing a compressed bit-stream from a digital image includes the steps of a) processing the digital image to produce a main subject belief map containing a continuum of belief values relating to the importance of subject and background regions in the image, b) performing a spatio-frequency transformation on the digital image to produce an array of transform coefficients, c) deriving a distortion-weighting factor for each transform coefficient from the belief map, and d) producing a compressed bit stream using an image compression system that is responsive to the distortion-weighting factors. The specific image compression system may be selected from a variety of image compression systems, including JPEG compression, JPEG2000 compression or vector quantization. The production of the main subject belief map involves the extraction of at least one structural saliency feature and at least one semantic saliency feature from the image, and the integration of the structural saliency feature and the semantic feature using a probabilistic reasoning engine into an estimate of a belief that a region of the digital image is the main subject.

The invention discloses an unmanned aerial vehicle scouting image synthesis compressed encoding method based on selective block transformation. The method comprises the steps of synthesizing the H.264 compressing scheme and the JPEG 2000 compressing scheme, carrying out selective algorithm adjustment and improvement on block transformation in the H.264 video coding standard, and obtaining a compressed code stream by means of compressed encoding. According to the unmanned aerial vehicle scouting image synthesis compressed encoding method based on the selective block transformation, the problem of limitation on image transmission bandwidth caused by limitation of size, weight and power consumption and other respects of an unmanned aerial vehicle platform, and influence of channels, external environment and enemy interference and other factors on actual image information transmission is effectively solved, uncompressed image source information is differentiable under the situation that still images before and after compression are similar in respect of PSNR and subjective quality evaluation of a scouting video is high, the compression ratio is greatly increased, and the scheme is systematic.

The invention discloses a self-adapting extraction and display method for JPEG2000 medical images which enables the client, in terms of network bandwidth resource, image browsing layout and clinician operation information, to self-adaptively adjust the image extraction and display manner in real time, improve current image extraction and display mode and to efficiently provide high-resolution image for the clinician step by step by utilizing superior characteristics of JPEG2000 compression algorithm and adopting priority encoding mode for important image data. The method enables the clinician to quickly acquire images of the patient and to obtain high-resolution images in time when the network bandwidth is unsteady or bottlenecked, thereby improving diagnose efficiency and serving more patients with limited medical condition.

The invention discloses a method suitable for compressing sequence images of an unmanned aerial vehicle. The method comprises the following steps: according to airborne auxiliary data, carrying out intelligent dynamic coding frame group division of the sequence images of the unmanned aerial vehicle; within a frame group, carrying out high-precision quick motion estimation of the first frame and the last frame to the current frame, thereby acquiring a number pair matching point; according to corresponding matching relation, obtaining projection transformation matrixes of the first frame and the last frame to the current frame so as to acquire a forecast image and residual error; combining residual error images of the first frame and the other frames of the same frame group into a singe image; and compressing the singe image by JPEG2000 to acquire a high-performance compression result by a global optimization pruning algorithm. The method takes into account the characteristics of the sequence images of the unmanned aerial vehicle and makes full use of the characteristics of airborne auxiliary information and the JPEG2000 compression algorithm; therefore, the method has the characteristics of low algorithm complexity, good compression performance, strictly controlled compression code rate, easily realized hardware, and the like.

The invention provides a head shoulder image reconstruction method based on a model and an object in a low bit rate video call. The method is characterized in that with the combination of advantages of object-based coding and model-based coding, a low bit rate model-and-object-based hybrid coding method is provided; the method performs 2D deformable model automatic training of a face region and then coding; for a head shoulder region, a 2D grid formed based on a Delaunay algorithm is adopted, grid iteration is used to well match with a head image; then the image is subjected to JPEG2000 compression to obtain object texture, and an object grid and the object texture are sent to a reception end through a channel and then coding is shared. The method has the high coding efficiency via the grid segmentation and texture compression and achieves good user experience. According to the invention, transmission of head shoulder videos in the low bit rate is achieved, the experience effect after video image reconstruction is still good, and the utilization efficiency of communication resources improved.

The invention provides a semi-fragile digital watermaking system based on non-redundant Contourlet conversion, which can complete watermak embedding by regulating the magnitude relationship of parent-child coefficients. By utilizing the semi-fragile characteristic of the parent-child coefficients, the invention can get robustness to JPEG compression, JPEG 2000 compression, Gaussian noise adding, Gaussian filtering and contrast stretching operation, but has vulnerability to replication and pasting baleful operation with change of work content information. An experimental result shows that the semi-fragile digital watermaking system of blind detection proposed by people can ensure that certification and location of tampering a region are accurately realized under the conditions of the false alarm rate being lower than 6.5 percent and MDR being lower than 1 percent. By utilizing the parent and child relationship of WBCT region, the system enhances the detection accuracy rate of tampering the region when being in associated attack by the baleful operation and non baleful operation.

The invention belongs to the image compression field in the information technology, in particular to a DSP efficient concurrent control method in a JPEG2000 compression algorithm. The current data read from a first memory are processed under bit-plane scanning to produce results which are wrote into a second memory, meanwhile, the pervious group of data is shifted to an external cache from a third memory; and the data are read from the second memory and are processed under arithmetic coding to generate results which are wrote into the third memory, meanwhile, the next group of data is shifted into the first memory from the external cache. The invention makes the concurrent implementation of EBC algorithm operation and data shifting possible. The invention can execute the shifting process in the process of executing any cycle, and the shifting process is executed at the background without occupying the processing time of CPU, that is equivalent to the data shifting process without time spending, thereby realizing zero-time data shifting.

The invention provides an information hiding based vector quantization compression method which can greatly improve the compression performance of a conventional vector quantization compression method. The PSNR can be up to 40 dB when the compression ratio is 16 times, so the PSNR performance of the information hiding based vector quantization compression is increased by more than 12 dB when compared with that of the conventional vector quantization compression method, the PSNR performance is increased by more than 5 dB when compared with that of a JPEG2000 compression method, and the PSNR performance can be increased by 13 dB for certain images; and the information hiding based vector quantization compression method is mainly used for transmission and storage. The information hiding based vector quantization compression method is characterized in that the information hiding technology is utilized to creatively select an image region of interest for embedding of special error correction information rather than embedding secret information in the vector quantization for joint encoding and hidden transmission, a receiving end extracts correction information from normal vector quantization index data without distortion, and the quality of a restored image is greatly improved. The information hiding based vector quantization compression method has a high-performance data compression effect and relatively simple hardware implementation, and not only can compress image data, but also can compress non-image data.

The invention discloses a real-time descending resolution conversion method and a device for JPEG2000 compression bit stream. The method includes the following steps: step A. the invention detects inputted JPEG2000 compression bit stream, extracts bit stream and modifies effective information of a main header and a splicing block in color component/part of the header of the splicing block, detects each splicing block/part of the header of the splicing block and an encoding data packet, throws away the splicing block containing high resolution information/ part of the header of the splicing block and the encoding data packet, and produces output compression bit stream with low resolution. The invention has the characteristics by high real-time performance and good expansion.

The invention relates to a K-means clustering based depth image encoding method, and belongs to the field of depth image encoding and decoding in 3D video. The K-means clustering based depth image encoding method is characterized by comprising the steps of segmenting a depth image into n types by adopting K-means clustering; extracting the boundary of a new depth image formed by each type of the depth image after segmentation, carrying out entropy encoding and transmitting the entropy encoded boundaries to a decoding terminal; carrying out down sampling on non boundary region pixel values, and carrying out entropy encoding on down sampling values; transmitting an encoded bit stream to the decoding terminal; recovering each type of data by using a partial differential equation (PDE) method to acquire n reconstructed depth images at the decoding terminal; overlaying the n reconstructed depth images acquired by recovery so as to form a complete depth image; and synthesizing a required virtual viewpoint image by using depth image based viewpoint synthesis technologies. The advantage is that the quality of a virtual viewpoint synthesized under guidance of the depth image acquired by compression according to the scheme provided by the invention is higher than JPEG and JPEG2000 compression standards.

The invention discloses a compression method suitable for a three-dimensional grid sequence, is suitable for compressing the three-dimensional grid sequence and improves the compression efficiency of the isomeric three-dimensional grid sequence, wherein each frame of the three-dimensional grid sequence has different topologic connection relationships. The method comprises the following steps: (1) utilizing a thin-plate spline (TPS) to carry out non-rigid registration on a geometry image sequence, wherein the geometry image sequence is generated in a way that a known three-dimensional grid sequence is subjected to parameterization and resampling; and (2) using an image compression algorithm JPEG (Joint Photographic Experts Group) 2000 to compress a residual error between every two frames of the geometry image sequence registered in the step (1).

The invention discloses a random computing method for an importance degree of a wavelet coefficient of a two-dimensional image. The present method is very rough and is generally used for only dividing foreground and background coefficients or appointing one importance degree to each code block. The random computing method comprises the following steps: firstly, initializing alpha as a 0 matrix and generating a random matrix r, wherein the row number and the line number are consistent with beta and the elements are uniformly distributed on a coordinate (-1, 1); defining beta'=sgn(r)*beta and performing wavelet conversion W on beta', thereby obtaining alpha': alpha'=W(beta'); finally, updating alpha:alphap=max(alphap, absolute value of alphap') and performing p0 on each position; and if alpha no longer changes, ending and outputting alpha. According to the random computing method provided by the invention as a middle step of a JPEG2000 implicit ROI encoding process, the importance degree of each element on an image space is converted into the importance degree of each coefficient on a wavelet domain. According to the random computing method provided by the invention, the more accurate control on the ROI area and importance degree of a JPEG2000 compressed image is realized.

The invention provides a color image quality evaluation method based on joint entropy, and belongs to the technical field of digital image quality objective evaluation, machine vision and artificial intelligence. The joint entropy in statistics is used for measuring the quality difference between a distorted image and a standard image, the image quality evaluation method based on the special jointentropy is provided, and the problem of quality distortion degradation brought to a digital image when the image is transmitted, stored, compressed, edited and the like is solved. The obtained imagedistortion evaluation data can objectively describe and evaluate the distortion degradation degree of the image, and is consistent with human eye perception characteristics. According to the evaluation method, objective evaluation can be carried out on distorted images such as noise, blurring, JPEG compression and JPEG2000 compression, especially low-degree distorted images; an evaluation result conforms to human eye perception, and the method has good evaluation performance, can be used in the fields of image fusion, image analysis, intelligent detection and the like, and has good applicationpotential and value.