30 results about "Color image coding" patented technology

A lossless image encoding/decoding method and apparatus. The lossless color image encoding apparatus includes a motion prediction image generator estimating a motion between a previous image and a current image and outputting a corresponding prediction image, a residue generator generating a temporal residue corresponding to a difference between a prediction image generated by the motion prediction image generator and the corresponding block of the current image with respect to different components of the color image, a prediction residue generator generating prediction residues by defining a linear-transformed value of one residue among the different components of the color image output from the residue generator as a predictor and using differences between each of the residues of the other components and the predictor, and an entropy encoder receiving the residue forming the predictor from the residue generator and the prediction residues from the prediction residue generator and generating a bitstream. Encoding methods, decoding apparatuses, and decoding methods can be implemented similarly.

A color image encoding and/or decoding system, medium, and method using inter-color-component prediction in a frequency domain. To encode an original image, including at least two or more image components, frequency domain transform may be performed with of each component of a color image, color component transform of the frequency domain transform coefficients, in frequency domain, may be performed based on the relationship between transform coefficients of the color image components in order to remove redundant information between color components, performing, and entropy encoding the removed redundant information data. According to the method, medium, and system, a color image or video data can be directly compressed effectively without a conventional color transform process. Furthermore, by using the relationship between image components, redundant information between color components varying with respect to the encoding mode may be removed so that the encoding efficiency can be enhanced.

The present invention relates to the compression of color image data. A combination of hard decision pixel mapping and soft decision pixel mapping is used to jointly address both quantization distortion and compression rate while maintaining low computational complexity and compatibility with standard decoders, such as, for example, the GIF/PNG decoder.

The present invention relates to the compression of color image data. A combination of hard decision pixel mapping and soft decision pixel mapping is used to jointly address both quantization distortion and compression rate while maintaining low computational complexity and compatibility with standard decoders, such as, for example, the GIF/PNG decoder.

The invention relates to an image acquisition device and a shooting method, and belongs to the field of monitoring. The image acquisition device comprises an image sensor, a light supplementing deviceand a light filtering assembly. The image sensor is located on the light emitting side of the light filtering assembly. The image acquisition device further comprises an image signal processing unit,a coding compression unit and an analysis unit. The image sensor is used for generating and outputting a first image signal and a second image signal through multiple exposures; the light supplementdevice comprises a first light supplement device, and the first light supplement device is used for carrying out near-infrared light supplement in a stroboscopic mode. The light filtering assembly comprises a first light filter, and visible light and part of near-infrared light pass through the first light filter; the image signal processing unit is used for obtaining a grayscale image according to the first original image signal and obtaining a color image according to the second original image signal; the coding compression unit is used for performing compression coding on the color image; and the analysis unit is used for intelligently analyzing the grayscale image. The precision of the analysis result can be improved.

The invention improves the refresh rate and minimizes the memory for display when reproducing a color image. A color image encoding device has a creation device which counts the number of colors used in color image data and creates a global palette which lists corresponding indexes when the number of colors is a specified value or less, a block division device which divides the color image data into a plurality of blocks, a local palette creation device which creates a local palette which lists indexes in the global palette when the number of colors in a block is less than the number of colors in the global palette, and a color index assigning device which assigns the indexes in the global palette to the input pixels when the number of colors is the same as the number of colors in the global palette, and assigns the indexes in the local palette to the input pixels when the numbers of colors is different from the number of colors in the global palette.

A depth image may be compressed and transmitted after being sampled to have less information before being coded, as opposed to a conventional scheme of compressing an original depth image. An uncompressed depth image of a non-transmitted depth image may be restored by sampling based on color information associated with a decoded color image and depth information associated with a decoded depth image. Thus, compression may be improved.

An image decoding method performed by a decoding device according to the present invention comprises the steps of: deriving an intra prediction mode for a current PU on the basis of a received bit stream; and performing reconstruction of a plurality of TUs located in an area of the current PU on the basis of the intra prediction mode, wherein the step of performing reconstruction comprises, with respect to a current block that is one of the plurality of TUs, a step of deriving a prediction sample of the current block on the basis of a first reference sample located in a prediction direction of the intra prediction mode and a second reference sample located in an opposite direction of the prediction direction, and a step of reconstructing a block to be reconstructed on the basis of the prediction sample.

The invention provides a novel color image coding method. The method is characterized by, according to the characteristic that a transfer matrix between RGB and YCbCr color space is a non-unitary matrix, that is, unequivalence of error between RGB images and YCbCr images, with minimization of interpolation error of an RGB space being an objective, carrying out combined optimized filtering on three components of Y, Cb and Cr, after filtering, the resolution of the component Y keeping unchanged, and the resolutions of the two components Cb and Cr being reduced; after finishing filtering, carrying out compression on the three components through a standard JPEG image compression method; and carrying out coding on the RGB images based on the above, so that coding efficiency is improved greatly. The method can improve coding efficiency of the RGB color images, is not high in complexity and is easy to realize.

The invention discloses a full-reference image quality evaluation method and system suitable for a visual two-dimensional code. Based on inherent characteristics of the visual two-dimensional code, distortion and distortion in three aspects of color, contrast and gradient are selected as reference indexes of a visual two-dimensional code quality evaluation scheme. The color similarity, the contrast similarity and the gradient similarity of the visual two-dimensional code are calculated respectively, and a visual two-dimensional code image quality evaluation result is obtained through final weighted average. According to the evaluation method, the problem that an existing classic image quality evaluation method is not suitable for visualized two-dimensional codes is solved; the visual two-dimensional code image is a color image; the characteristics of image structure, contrast distortion and the like generated in the coding process are considered in the scheme, the visual two-dimensional code coded image quality is evaluated in a more targeted mode, optimization and improvement of the visual two-dimensional code scheme are better guided to better evaluate the characteristics of thevisual two-dimensional code scheme, and a better reference basis is provided for optimization and improvement of the coding scheme.

The invention discloses an image encryption method and device based on cascade transformation, and the method comprises the steps: S1, generating a phase mask according to a chaotic sequence; s2, randomly generating a real integer matrix, and encoding the real integer matrix and the first color image to generate a full quaternion matrix; s3, performing modulation and quaternion Gyrator transformation on the full quaternion matrix according to the phase mask to obtain a first amplitude and a first phase; s4, encoding the first amplitude and the second color image to generate a quaternion matrix, and performing amplitude truncation to obtain a second amplitude and a second phase; s5, multiplying the first phase by the second phase, and performing modulation and quaternion Gyrator transformation on the quaternion matrix according to a phase mask to obtain a third amplitude and a third phase; s6, repeatedly executing S4 and S5 until the Nth amplitude and the Nth phase of the last color image are obtained. The method has relatively high transmission efficiency and security.

Described is an image compression technology by which a coefficient representative of a chrominance component corresponding to an (x, y) coordinate pair is coded into a symbol, along with plurality of context events associated with that symbol, to facilitate more efficient context-based arithmetic coding. For example, four context events may be generated, including one context event based on the corresponding (x, y) coefficient value in the luminance component, and three context events based on other luminance coefficients that have adjacent horizontal, vertical and diagonal relationships with the corresponding luminance component's coefficient, respectively. In one example implementation, coding the chrominance coefficient and computing the plurality of context events occurs in a zero coding pass of an entropy coder. A sign coding pass and a magnitude refinement pass may be performed to obtain further symbols for the context-based arithmetic coding.

The invention discloses a color image reconstruction method and device, and an image classification method and device, and the method comprises the steps of extracting a generation network model and adiscrimination network model through the training of a tensor-based deep convolution generative adversarial network, obtaining a generator based on the generation network model, and obtaining a decoder based on the discrimination network model; converting a color image to be classified into a color image code by using the decoder, wherein the similarity between the spatial distribution of the color image coding and the spatial distribution of the noise is higher than a preset threshold, and the noise is obtained from a potential space; repeatedly inputting the color image codes into the generator to generate a plurality of target color images; evaluating and scoring the plurality of target color images by using the discrimination network model; and taking the target color image of which the score meets the requirement as the reconstructed color image.

Techniques for improving remote rendering and reprojection are disclosed herein. A color image is generated, where this color image includes overlapping content regions. A depth buffer is generated for the color image and includes depth values for the pixels in the color image. The depth buffer includes both essential and non-essential depth discontinuities. While preserving the essential depth discontinuities, the non-essential depth discontinuities are eliminated from the depth buffer. New non-essential discontinuities are prevented from being included in the final version of the depth buffer. The color image is encoded into a color image video stream, and the modified depth buffer is encoded into a depth buffer stream. The color image video stream and the depth buffer stream are then transmitted to a remotely located HMD. The HMD then reprojects the color image based on the depth values in the depth buffer.

The invention discloses a color image encryption method and device, and the method comprises the steps: a color image being coded into a first quaternion matrix; dividing the quaternion matrix into non-overlapping sub-blocks, and performing modulation and quaternion Gyrator transformation on each sub-block to obtain a second quaternion matrix; extracting a real component, a first imaginary component, a second imaginary component and a third imaginary component of the second quaternion matrix, and constructing to obtain a first complex matrix and a second complex matrix; carrying out multi-resolution decomposition on the first complex matrix and the second complex matrix to obtain an approximate component and a detail component, and recombining to obtain a third complex matrix and a fourthcomplex matrix; and performing Gyrator transformation with an angle of beta on the third complex matrix and the fourth complex matrix to obtain a first ciphertext image and a second ciphertext image respectively. According to the method, the complexity of a single-channel processing mode is effectively avoided, meaningful content of the image can be hidden, and the method can be applied to the field of multimedia information security.

The invention discloses an RGB color image coding method based on a single-size nano-structure metasurface, and the method comprises the steps: achieving the multiplexing of three information channels through a metasurface polarizer which is only composed of a plurality of nano-brick structure unit arrays through the degeneracy of a steering angle of a nano-brick structure unit and the conversion relation between decimal data and binary data; the three information channels are mutually independent and are respectively used for storing coding information of R, G and B color components. According to the invention, the conversion among three channels can be realized by changing the polarization direction of incident polarized light and the direction of the light transmission axis of the polarization analyzer. The information stored in the three channels is unrelated and can be designed at will, and the information storage requirement of the RGB color image is met. Moreover, the metasurface designed by the invention is simple in structure, can be highly integrated, and is suitable for the trend of miniaturization and integration of devices.