106 results about "Luminance channel" patented technology

A method of improving a first color filter array image from an image sensor having a plurality of color channels and a panchromatic channel, includes capturing the panchromatic channel at a different exposure time than at least one of the color channels with the image sensor; using the color channels to provide a luminance channel; and analyzing the color filter array image and the luminance channel to determine defective pixels in the color channels and using neighboring color and luminance pixel values to improve the defective pixels to produce a second color filter array image or full-color image having at least one improved channel.

A method of removing ringing and blocking artifacts from a decompressed digital image. In one method, a background value of the digital image a background region and foreground regions is determined, and a threshold value is computed. A mapping of the digital image is then generated by thresholding the digital image based on the threshold value to produce a thresholded image, and enlarging the foreground regions of the thresholded image to form a map image. The mapping includes the background pixels of the map image. The background region of the decompressed digital image is then cleansed based on the mapping. In an alternate method, ringing artifacts are removed from a decompressed digital image based on a signal-to-noise ratio of the image. In yet another alternate embodiment, ringing artifacts are from a decompressed digital color image that includes a chrominance channel and a luminance channel. An alternate embodiment removes ringing and blocking artifacts.

The embodiment of the invention discloses a non-contact heart rate measurement method and a device based on Euler image magnification, used for solving the technical problems existing in the existingnon-contact heart rate measurement method that the heart rate is great in same-frequency noise interference and is greatly influenced by an environment temperature, isolation signal authenticity lacksjudgment and the like. The non-contact heart rate measurement method and device based on Euler image magnification in the embodiment of the invention comprises the following steps: S1, magnifying tiny change of radial artery jump in a video through an Euler image magnification technology; S2, performing luminance variance statistics on a video frame pixel point luminance channel after magnifyingthe tiny change of radial artery jump in a time domain, performing skin segmentation on the video frame subjected to magnification of the tiny change of radial artery jump, and extracting a radial artery jump area; and S3, performing time-frequency analysis on the radial artery jump area so as to calculate the heart rate.

A method of processing a color digital image having a luminance channel and one or more chrominance channels to improve the tone scale characteristics of the image, includes the steps of: producing a control signal from the one or more chrominance channels; generating a pedestal signal containing mainly low frequency modulation by filtering the luminance channel with a spatial filter, whereby the operation of the spatial filter is modulated by the control signal; and producing a texture signal by subtracting the pedestal signal from the luminance channel.

Methods, systems, and computer programs for improving compressed image chroma information. In one aspect of the invention, a resolution for a red color component of a color video image is used that is higher than the resolution for a blue color component of the color video image. Another aspect includes utilizing a lower or higher value of a quantization parameter (QP) for one or more chroma channels as compared to the luminance channel. Another aspect is use of a logarithmic representation of a video image to benefit image coding. Another aspect uses more than two chroma channels to represent a video image.

Provided are an apparatus and method for enhancing an image using a color channel. A pre-processing unit generates an inverted image by inverting a luminance component estimated from a red (R) channel among color channels of a red, green, and blue (RGB) color space of an input image. A channel merging unit generates a merged luminance (L) channel by merging an L channel of an International Commission on Illumination (CIE) L*a*b* (CIELab) color space of the input image and the inverted image. A contrast enhancement unit enhances contrast by expanding a histogram of the merged L channel. A color restoration unit combines the merged L channel whose contrast has been enhanced and chromaticity components of the input image, and converts a resultant color image to the RGB color space, thereby generating a restored image.

The invention relates to the field of video processing, and discloses a color image denoising method and a system thereof. In the method and the system thereof, cross-channel invariable information is extracted from a luminance channel image for the denoising treatment on a chrominance channel image, so that a false color edge or texture can be eliminated, the fuzzyness of the edge part can be reduced, and better integral denoising effect can be obtained. The cross-channel invariable information can be edge information, texture information, noise intensity and the like. The luminance channel may be firstly processed with local data conversion; the cross-channel invariable information is extracted from a conversion domain; and characteristic information, such as edge texture and the like can be extracted from local image data more effectively based on different characteristics of a signal represented in the conversion domain, and consequently, the chrominance channel image can be denoised better based on the information.

The present application relates to a lane line detection method and apparatus. The method comprises the following steps of: converting an image to be processed into a color space including a saturation channel and a luminance channel to obtain a color space image; based on the saturation channel and brightness channel of color space image, obtaining the image segmentation information of color space image by filtering, wherein the image segmentation information includes: first edge information obtained by gradient direction filtering of saturation channel and second edge information obtained byhorizontally filtering a saturation channel and a luminance channel; determining a lane line binary map based on image segmentation information; according to the effective pixel points in the binarydiagram of lane line, carrying out the curve fitting to obtain the fitting lane line. The method can effectively avoid the interference of shadows, vehicles or other obstacles, and improve the accuracy of lane fitting.

A system and method for classifying an image block of a printed image into contone, halftone, or error diffusion classes, includes scanning the printed image; selecting an n by n block of pixels from the scanned image in a luminance channel; calculating an array of DCT coefficients of the pixel block, wherein the calculated DCT coefficients are representative of spatial frequency and spatial orientation of the pixel block; comparing the array of DCT coefficients with an array of predetermined values, wherein the array of predetermined values are indicative of contone, halftone and error diffusion classes; and determining the image classification of the pixel block based on the comparison of the DCT coefficients with the array of predetermined values. If the image is determined to be halftone, then the method further evaluates the DCT coefficients to determine the frequency of the halftone screen.

An exposure correction method for digital images first computes a gray-level histogram of an image. Then determine whether the exposure of the image is normal from the gray-level histogram, thereby determining an exposure threshold. The central region of the image is extracted to find an average brightness Iave. The average brightness Iave and a destination brightness Idest are used to determine an adjusting curve y=f(x). The brightness channel is adjusted according to a constructed correspondence table. Therefore, the image processing effects are enhanced even though the processing time is reduced.

The invention relates to computer graphics, which is an illumination estimation method based on a monocular camera. The method comprises the following steps: a monocular camera acquires an RGB image as an input of a depth estimation; Convolution neural network for depth estimation of monocular camera is constructed and trained. The RGB image is input to the trained convolution neural network for depth estimation, and the depth prediction value is obtained, and the depth prediction map is output. The depth prediction value is upsampled to match the size of the depth prediction map with the RGBimage, and the upsampled depth prediction value is used as the input of the illumination estimation. The RGB image is transformed into CIELab color space, and the luminance channel information is usedas the input of illumination estimation. The spherical harmonic coefficients of the light source information in all directions of the real scene can be obtained by using the luminance channel information and the depth prediction value to estimate the illumination. This method uses monocular camera to obtain the light source information in each direction of the real scene, and effectively improvesthe fidelity of rendering virtual object in AR technology.

A method and system of correcting motion artifacts are provided for video captured from interlaced multiple exposure sensors. The following are included: (a) motion artifacts detection of a pixel area, (b) smoothing of the detected pixel area, and (c) motion artifacts correction. The motion artifacts pixels are detected by comparing the luma difference between a current image frame and a previous image frame; the pixels of the surrounding area are also checked. A smoothing operation is applied to the detected artifacts area, in order to remove isolated pixels and enlarge the detected area. Corrections are then provided using a multistage filter for the luma channel and a mean filter for the chroma channel.

A composite masking system and method for improving the invisibility of high-definition video watermarking. The composite masking system includes a watermark generation module, a mask generation module, and watermark embedment means. The watermark generation module generates a basic watermark pattern using a private key, and generate a watermark pattern by repeatedly extending the basic watermark pattern. The mask generation module generates a Noise Visibility Function (NVF) mask using NVF masking means, an adaptive dithering mask using adaptive dithering masking means, and a contour mask using contour masking means. The watermark embedment means generates a composite mask by multiplying the NVF mask, the adaptive dithering mask and the contour mask together, multiplying the composite mask and the extended watermark pattern together, and embedding the result of the second multiplication in the luminance channel of an original image.

The embodiment of the invention provides a tooth identification method, device and system. The method comprises the following steps of: according to the obtained coordinates of lip feature points, determining a target image which comprises teeth to obtain the approximate area of the teeth; combining with a characteristic that the teeth are bright on a luminance channel, converting the target image into a preset color space of which the luminance detection is sensitive; on the basis of a luminance grayscale image and a first masking grayscale image, obtaining a second masking grayscale image; on the basis of a chromaticity image and a saturability image, obtaining a lip probability image; and finally, on the basis of the second masking grayscale image and the lip probability image, obtaining a third masking grayscale image, wherein the pixel value of a tooth part in the third masking grayscale image has an obvious difference with pixel values on other positions, and an area which is formed by the pixels of which the pixel values are greater than or equal to a third preset value in the third masking grayscale image as a tooth area. Therefore, a purpose that the teeth can be quickly and accurately identified is realized.

The invention discloses a sequence remote sensing image tone consistency correction method and a system. The method comprises the following steps: transferring a colored sequence image from RGB color space to L[alpha, beta] color space to perform the tone transfer preprocessing and the global gain compensation of luminance channels; in color channel histogram mapping, adjusting the image gray-scales of color channel [alpha] and color channel [beta] separately; transferring all images from L[alpha, beta] color space to RGB color space and outputting and saving the processed results. According to the invention, the method and system can effectively suppress or eliminate the differences in brightness and the color existing in the images by utilizing the tone corresponding relationship of the overlapping areas of adjacent images. The method and system can also greatly reduce the image distortion caused by the correlation between the channels, and automatically select the reference color by searching the maximum consistent image subset, thus avoiding the problem of manually selecting the reference color.

The invention relates to a pulse coupled neutral network (PCNN) disabled face image segmenting method simulating visual cells to feel a field property. The method comprises the following steps of feeling a structure of a feedback domain connection matrix in a field model optimized pulse coupled neutral network by visual cells, obtaining a pulse coupled neutral network model with a directionality and scale; adjusting the model parameters according to the characteristics of a disabled face image; and finally inputting the brightness channel information of the disabled face image to the model to produce human visual simulated face segmenting result. As the cell felt field model optimizes the connection matrix, the pulse coupled neutral network has directionality and scale, the correction rate for segmenting is improved, and better robustness for face segmenting under natural lighting is realized. In addition, compared with the other methods, the method provided by the invention has the advantages of good separation degree between different image contents, well kept details of the image, fast segmenting speed and the like.

The invention provides a method for detecting image flicker stripes and a method for adjusting image exposure time. The method for detecting the image flicker stripes comprises: S110, collecting N continuous image sequences, N being an integer larger than 1, S120, executing a flicker frequency determining step on each frame of image in the N continuous image sequences, and the flicker frequency determining step comprises: S121, obtaining a brightness channel image of a current frame; S122, calculating a line mean vector of the adjacent frame images; S123, calculating a row difference vector; S124, calculating an average value of the row difference vector to serve as an amplitude center of a waveform of the row difference vector of the current frame image; S125, determining a position vector Pose (m); S126, determining at least one predetermined flickering frequency from the predetermined flickering frequency set as the flickering frequency of the current frame of image; and S130, determining the flicker frequency according to the proportion of each predetermined flicker frequency in the predetermined flicker frequency set in the N frames of image sequences. According to the method,the existence and the frequency of flickering in the image frame sequence can be efficiently and accurately detected.