93 results about "Noise strength" patented technology

A method and system is provided for estimating the strength of block artifacts at each block boundary, based on global and local edge statistics computed from the input image (frame or field picture) in the spatial domain. Such a method systemically measures the strength of the compression artifacts that are associated with block-based compression / coding schemes such as JPEG, MPEG, and H.26x.

The invention provides a remote sensing image restoration method combining wave-band clustering with sparse representation. In order to improve the spatial resolution of a hyperspectral remote sensing image, according to the characteristics of rich spectral dimension information of the hyperspectral image and different noise strength of different wave bands, a multiband image restoration model is built, the wave bands are mutually restrained and complemented by the aid of high similarity of the wave bands and redundant information, and finally, the high-quality hyperspectral image is obtained. Firstly, the wave bands of the hyperspectral image are clustered, and a large number of wave bands are divided into a small number of categories with large relevant information difference. Secondly, a cluster of wave bands in the same category is built into an integral variation training multiband dictionary by the compressive sensing theory, and the dictionary is used for completing image restoration. Relevancy of a plurality of wave bands is sufficiently used for restoring target images, the spectral characteristics of the target images are kept, and restoration results have higher spatial information and spectral information keeping performance.

The invention provides a random resonant current weak information identification method based on a linear searching strategy. A signal-to-noise ratio is used as a condition for generating random resonance by a control system, and an advantage of maximizing the output signal-to-noise ratio of a noise strength control system is realized. Furthermore a maximal signal-to-noise ratio max(SNR) is used as a system optimization target function. Through estimating a weight function of a system structure parameter a and a noise strength D in each iteration process, and then correcting the weight function in an iteration process, the system finally outputs the maximal signal-to-noise ratio, thereby improving calculating capability in determining the system structure parameter through optimizing the signal-to-noise ratio (SNR), and realizing adaptive random resonance of the current signal. Because system searching difficulty and weight function complexity are reduced in an iteration process, calculation time is reduced and the method is particularly suitable for periodical signal detection of the current.

In a video processing device, scale of a video image is detected for vertical and horizontal directions based on pixel information, for example, per pixel vertical and horizontal gradients. Gradients are utilized or discarded based on picture format, standard deviation of luma levels and pixel location relative to black border edges, graphics and / or overlaid content. Mosquito noise filters are adapted based on scale and / or noise strength. Median and / or linear filter results are selected based on a weakest, a strongest and / or a blended result. Horizontal and vertical operations are performed separately for edge detection, edge strength determination, filtering and filter correction control. Horizontal and vertical block grid spacing and grid shift are determined. Block noise strength is determined. Block noise filters are configured based on scaling and / or noise strength. Filter corrections are limited based on block noise strength. Noise reduction results may be blended to generate a pixel correction value.

An apparatus and method for estimating scale ratio and noise strength of an encoded image includes an edge detection unit, a projection histogram calculation unit, a distance histogram calculation unit, a scale ratio estimation unit, a block boundary determination unit, and a noise strength estimation unit. Compressed noise, such as a block effect, included in an image can be efficiently reduced without prior information about the image.

A system for hiding secret data in halftone images is disclosed. The system includes an image input module, a halftoning processing module and an image output module. The image input module reads an original image data and a secret image data. The halftoning processing module is coupled to the image input module and receives the original image data and the secret image data, performs a first error diffusion process to the original image to generate a first halftone image and performs a second error diffusion process to the original image data and the secret image data to generate a second halftone image. The image output image module is coupled to the halftoning processing module and outputs the first halftone image and the second halftone image, wherein the second error diffusion process comprises adding or subtracting a variable noise strength to or from each pixel of the secret image.