Stmicroelectronics Asia Pacific Pte Limited

Xiaoyun Deng

Lucas Hui

Patricia Wei Yin Chiang

Patricia Chiang

Digital noise removal methods and systems for picture quality improvement on next generation high quality set-top-box and digital TV SOCs is disclosed with particular to a de-blocking method and system that is effective on on-grid and off-grid blocky artifacts generated by lossy video compression standards. Blocky artifacts are filtered by extracting motions vectors for a current pixel block, calculating off-grid positions based on the extracted motion vectors, and applying de-blocking filtering along the calculated off-grid positions. The methods and systems can further skip filtering on-grid blocky artifacts to be filtered by an on-grid de-blocking filter known in the art.

Motion compensated de-blocking

A method and apparatus are provided for detecting banding noise in a digital signal representative of an image. The method includes determining, by a banding noise detector, a count of increment steps in pixel values and a count of decrement steps in pixel values along a filter direction in a neighborhood of a current pixel of the image, checking, by the banding noise detector, if the count of increment steps or the count of decrement steps in the neighborhood of a current pixel exceeds a step threshold value, and classifying, by the banding noise detector, the current pixel as being located in the banding noise zone if the count of increment steps or the count of decrement steps does not exceed the step threshold value.

Banding noise detector for digital images

A method and apparatus are provided for filtering banding noise in a signal representative of an image. The method includes detecting, by a banding noise detector, banding noise in a neighborhood of a current pixel of the image, determining, by an adaptive filter weight decision unit, a number of banding steps in the neighborhood of the current pixel, determining, by the adaptive filter weight decision unit, a difference between a current pixel value and a previous output value, selecting, by the adaptive filter weight decision unit, a filter weight based on the number of banding steps, the difference between the current pixel value and the previous output value, and the detected banding noise, and filtering, by a recursive filter, the current pixel value according to the selected filter weight.

Recursive de-banding filter for digital images

The present invention relates to systems and methods for inverse telecine or video de-interlacing for picture quality improvement on set-top-box and TV products. The system comprises a film mode detector at the picture or sequence level, a global mixed video and film content detector at the region, picture, or sequence level on top of the detected film content, and a local video content detector at pixel level on top of the detected mixed video and film content. Inverse telecine processing is applied on detected film content fading in with a locally de-interlaced local video content. The invention further provides an apparatus and method for globally detecting mixed video and film content at region, picture, or sequence level. Such apparatus and method comprise a plurality of detectors for robustness and increased detection accuracy.

Apparatus and method for inverse telecine with local video de-interlacing

Apparatus and methods of motion detection for mosquito noise reduction in video sequences are provided. In one aspect, a method of motion detection in a sequence of digital images classifies a pixel of a plurality of pixels of a current image frame represented by a digital video input signal as a motion or non-motion pixel. A motion value for the pixel is calculated based on the classification of the pixel. The motion value is mapped to a coefficient of a temporal filter based on a control curve. A digital video output signal is generated based on the coefficient.

Apparatus and method of motion detection for temporal mosquito noise reduction in video sequences

Aspects of the invention are directed towards an apparatus and method for detecting conventional and exotic cadences in video sequences. The cadence detector includes a motion auto-correlation unit using the inter-frame/field motion information to detect the cadence and a motion cross-correlation unit using the inter-frame/field motion information and the detected cadence to determine the cadence phase. The cadence detector also may include a reset signal generator to generate a reset signal to control the motion auto-correlation unit and the motion cross-correlation unit. The exotic cadence detector is robust and may support many cadences with reduced cadence detection latency as compared to the prior art.

Apparatus and method for exotic cadence detection

Aspects of the invention are directed towards an apparatus and method for detecting local video pixels in mixed cadence video. The local video detector comprises a comb detector that is adaptive to the contour of moving objects and local contrast, a motion detector that is robust to false motion due to vertical details, and a fader value estimator that provides a video confidence value to a fader that combines film mode and video mode processing results. The coupling of the local video detector to a film mode detector increases the robustness, accuracy, and efficiency of local film/video mode processing as compared to the prior art.

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Singapore, Singapore

Xiaoyun Deng