33 results about "Color image compression" patented technology

The invention discloses a coloring weight real-time separating method for coloring image compression bit stream, which comprises the following steps: detecting marks of a SOC marking segment and a SIZ marking segment for input bit stream, and starting to separate the coloring weight in the bit stream after detecting the marks; and performing different processing for different marking segments in the bit stream, and finishing the real-time separating operation of the coloring weight after receiving a bit stream ending mark. The invention further discloses a coloring weight real-time separating device, which comprises a shift register, a marking segment mark detecting and control module, a control bus, a SIZ marking segment processing module, a COD marking segment processing module, a QCD marking segment processing module, a COC marking segment processing module, a QCC marking segment processing module, a SOT marking segment processing module and a bit stream ending processing module. The invention achieves the JPEG2000 coloring weight separating function required by hardware, thus being advantageous for parallel execution of JPEG2000 decompression. The invention has good expandability and portability.

The invention discloses a quaternion field colored image compressed sensing recovery method based on a Quasi Newton algorithm. The quaternion field colored image compressed sensing recovery method comprises the following steps of: converting a colored image two-dimensional matrix to a two-dimensional matrix of the quaternion field; and carrying out compressed sensing on the two-dimensional matrix of the quaternion field once to recover the original colored image, so that the operation time is saved in comparison with a conventional method of carrying out compressed sensing on the three vectors, i.e. RGB (Red, Green, Blue) of the colored image respectively. According to the quaternion field colored image compressed sensing recovery method based on the Quasi Newton algorithm disclosed by the invention, a quaternion matrix signal is written into an Euler form of a quaternion, the amplitude and the phase are adopted as novel bound terms of compressed sensing optimization problems, therefore, the recovery effect is better in comparison with the conventional method which converts the data of the three channels, i.e. RGB of the colored image into three real-number two-dimensional matrixes for being processed respectively. According to the quaternion field colored image compressed sensing recovery method based on the Quasi Newton algorithm disclosed by the invention, the result image is a mean value of an image obtained by carrying out compressed sensing decoding in rows and an image obtained by carrying out compressed sensing decoding in columns, therefore, the obtained image is smoother than the image which is recovered by being processed only in rows or in columns.

The invention provides a color image compression and encryption method based on compressed sensing and double random encryption mechanism. This method first decomposes the plaintext image into three components R, G and B, and then DWT transforms them respectively, and then uses the index vector D 1 , D 2 , D 3 , D 4 Perform double random position scrambling on the sparse coefficient matrix, then perform compression measurement and quantization on the scrambled matrix, and perform simultaneous double random pixel value diffusion between and within the R, G, and B components of the quantized matrix, and finally obtain ciphertext image. The parameters and initial values ​​of the four-wing hyperchaotic system and the Logistic-Tent chaotic system are generated by using the plaintext image information and external key, and then the parameters and initial values ​​are brought into the Logistic-Tent chaotic system to generate the chaotic sequence to construct the measurement matrix; The parameters and initial values ​​are brought into the four-wing hyperchaotic system, and the generated four chaotic sequences are sorted to obtain four index vectors, which are respectively used in double random position scrambling and diffusion.

The invention provides a color image compression method based on a reaction-diffusion equation set. The color image compression method belongs to the field of image processing technologies. The colorimage compression method comprises the steps of: firstly, converting a color image into a grayscale image in a compression phase, compressing the grayscale image by using a JPEG compression method, then selecting a number of representative pixel points in the color image by utilizing a local optimal strategy, and only storing the compressed grayscale image and the selected representative pixel points to achieve the purpose of compression; and decompressing the stored data into the original color image by utilizing the reaction-diffusion equation set in a decompression phase. The color image compression method based on the reaction-diffusion equation set has the advantage of reducing a storage space of the color image, so that the display effect of the decompressed color image is clearer, and the details are more abundant, meticulous and the like.

A digital encoding and decoding method of high bit-depth gray scale medical images allows standard 3-channel color image compression algorithms to be used to compress and de-compress such encoded high bit-depth gray scale images without significant image quality loss. The digital encoding and decoding method may be used to improve the network transmission, storage and rendering of such gray scale images in a standard web browser.