11 results about "Banding Artifact" patented technology

A system for reducing artifacts when imaging under pulse-width modulated illumination. A controller captures, with an image sensor, images as frames of a video of a target in an environment in which the target is illuminated by a pulse-width modulated light source. In doing so, the controller sets a first parameter for the image sensor as a function of a light pulsation period of the pulse-width modulated light source to reduce artifacts in the images associated with the pulse-width modulation of the light source. Further, the controller determines whether residual banding artifacts resulting from the pulse-width modulation of the light source are unacceptable in the images captured with the image sensor. Additionally, the controller performs, in response to a determination that residual banding artifacts are present in the images, image processing to correct the residual banding. The system outputs the resulting images with reduced artifacts for viewing by a user.

The invention relates to the technical field of image artifact recognition, in particular to an image recognition method for cardiovascular intervention postoperative complication risk prediction. The strip-shaped artifact structures are independently distributed in a regular manner and generally show the distinguishing characteristics of high consistency at the angle, and the strip-shaped artifact structures are screened out according to the linear texture distribution consistency condition; calculating the possibility of the artifact structure by combining the complex branch structure of the blood vessel, the sequential change of the diameter of the blood vessel and the characteristic that the contrast agent fluctuates along with blood flow, so as to screen out a tubular artifact structure with relatively low conformity with the blood vessel characteristics; the finally obtained banded artifact structure and tubular artifact structure representing the artifact area are more accurate, and compared with a target detection method, the image recognition processing method based on machine learning is higher in efficiency.

A system for reducing artifacts when imaging under pulse-width modulated illumination. A controller captures, with an image sensor, images as frames of a video of a target in an environment in which the target is illuminated by a pulse-width modulated light source. In doing so, the controller sets a first parameter for the image sensor as a function of a light pulsation period of the pulse-width modulated light source to reduce artifacts in the images associated with the pulse-width modulation of the light source. Further, the controller determines whether residual banding artifacts resulting from the pulse-width modulation of the light source are unacceptable in the images captured with the image sensor. Additionally, the controller performs, in response to a determination that residual banding artifacts are present in the images, image processing to correct the residual banding. The system outputs the resulting images with reduced artifacts for viewing by a user.

This paper proposes a low-complexity, hardware-friendly technique for video decoding systems to mitigate striping artifacts while maintaining compression efficiency. Generally, the proposed technique consists of two stages: a striping detection stage and a destripping stage. The striping detection stage identifies potential striping artifact regions in the image / video based on gradient information and other data. The destripping stage applies correction techniques to these identified regions. In one implementation, the destripping modifies the filtering logic proposed by previous video decoding standards for other filtering applications to mitigate striping. When implemented on the AVI video decoding standard and the AOM Video Model (AVM) reference software, the proposed technique significantly improves subjective quality at a reasonable hardware implementation cost. The methods and implementations presented in this document can be beneficially applied to various image / video decoding standards and systems.

The invention discloses a B0 robust heart T1 quantitative imaging method, and belongs to the field of magnetic resonance quantitative imaging, and the method comprises the steps: designing a double-phase increment heart T1 quantitative imaging collection sequence, and collecting original data based on the double-phase increment heart T1 quantitative imaging collection sequence; constructing a simulation signal dictionary based on a magnetic resonance physical model; and matching the original data with the simulation signal dictionary to obtain an optimal dictionary entry corresponding to the original data, and obtaining a T1 quantitative graph and a B0 quantitative graph based on the optimal dictionary entry. According to the method, B0 information is designed and coded by adopting a double-phase increment sequence, T1 quantitative imaging of B0 robustness is realized, the influence of non-uniformity of a B0 field under high field intensity is reduced, and the interference of bSSFP black-band artifacts is reduced. The method combines the dictionary matching technology to jointly estimate T1 and B0, provides more accurate T1 estimation and B0 quantitative graphs, is easy to deploy and apply in an existing MRI platform, and has high implementation and migration feasibility.

The present application relates to the technical field of halftone, in particular to a multi-level halftone method and system based on image partition error diffusion, comprising: dividing the input original image into flat regions and non-flat regions, and using gray level replacement quantization in the flat regions to increase the high-frequency blue noise characteristics of the halftone result, forming a distribution close to blue noise to reduce the banding distortion that can be observed by the human eye, while introducing an edge preservation mechanism in the non-flat regions, calculating the cumulative weight error according to the texture information in the texture region information mask, and introducing the propagation error in the total error to avoid the edge pixels in the image being affected by the error of the adjacent pixels, protect the edge details, and avoid the degradation of the edge details. The present application can alleviate the banding artifact phenomenon in the flat region, protect the texture and edge details, can provide halftone characteristics close to the ideal, and improve the output quality of the halftone image.

A computer-implemented method includes accessing a video frame that includes a plurality of pixels. The method also includes generating a spatial mask that identifies pixels whose likelihood of causing banding within the video frame meets at least a minimum threshold likelihood. The method also includes computing a local distribution for a region of the video frame that includes at least those pixels that were identified by the spatial mask to detect bands in the video frame. The method further includes determining that the detected bands in the video frame are at least a minimum threshold size. The method also includes applying dithering to those detected bands in the video frame that were determined to meet the minimum threshold size. Various other methods, systems, and computer-readable media are also disclosed.

A system for reducing artifacts when imaging under pulse-width modulated illumination. A controller captures, with an image sensor, images as frames of a video of a target in an environment in which the target is illuminated by a pulse-width modulated light source. In doing so, the controller sets a first parameter for the image sensor as a function of a light pulsation period of the pulse-width modulated light source to reduce artifacts in the images associated with the pulse-width modulation of the light source. Further, the controller determines whether residual banding artifacts resulting from the pulse-width modulation of the light source are unacceptable in the images captured with the image sensor. Additionally, the controller performs, in response to a determination that residual banding artifacts are present in the images, image processing to correct the residual banding. The system outputs the resulting images with reduced artifacts for viewing by a user.

The invention relates to the technical field of halftoning, in particular to a multi-level halftoning method and system based on image partition error diffusion, and the method comprises the steps: dividing an input original image into a flat region and a non-flat region, and employing gray level replacement quantization in the flat region to increase the high-frequency blue noise characteristic of a halftoning result, the method comprises the following steps of: forming distribution close to blue noise to reduce stripe distortion which can be observed by human eyes, introducing an edge preserving mechanism into a non-flat region, calculating an accumulated weight error according to texture information in a texture region information mask, and introducing a propagation error into a total error to prevent edge pixels in an image from being influenced by errors of adjacent pixels, so that the image quality is improved. Edge details are protected, and edge detail degradation is avoided. According to the method, the stripe artifact phenomenon of a flat area can be relieved, texture and edge details are protected, nearly ideal halftone characteristics can be provided, and the output quality of a halftone image is improved.