Abstract:
An original image is sharpened by obtaining a first frequency-domain representation of the original image, selecting one or more elements from this first representation based on one more criteria such as element magnitude and frequency, scaling the selected elements according to one or more scale factors, and forming a second frequency-domain representation by combining the scaled selected elements with the unselected elements of the first representation. A sharpened reproduction of the original image may be generated by applying an inverse transform to the second frequency-domain representation. A technique for deriving the value of the one or more scale factors is also discussed.
Abstract:
An automatic testing method and device is described that can test a video sequence coder/decoder system and either assess the quality of decoded sequences or rate the fidelity of the coding chain. The device produces synthetic test patterns that induce the appearance of known artifacts, then tracks and evaluates such artifacts. Based on this evaluation, it can rate the system's performance in a way that correlates well with human assessments. In our testing device, the quality estimation module performs this function.
Abstract:
Downsampling and inverse motion compensation are performed on compressed domain representations for video. By directly manipulating the compressed domain representation instead of the spatial domain representation, computational complexity is significantly reduced. For downsampling, the compressed stream is processed in the compressed (DCT) domain without explicit decompression and spatial domain downsampling so that the resulting compressed stream corresponds to a scaled down image, ensuring that the resulting compressed stream conforms to the standard syntax of 8.times.8 DCT matrices. For typical data sets, this approach of downsampling in the compressed domain results in computation savings around 80% compared with traditional spatial domain methods for downsampling from compressed data. For inverse motion compensation, motion compensated compressed video is converted into a sequence of DCT domain blocks corresponding to the spatial domain blocks in the current picture alone. By performing inverse motion compensation directly in the compressed domain, the reduction in computation complexity is around 68% compared with traditional spatial domain methods for inverse motion compensation from compressed data. The techniques for downsampling and inverse motion compensation can be used in a variety of applications, such as multipoint video conferencing and video editing.
Abstract:
In one example, a method includes identifying a pixel in an image frame that is a candidate for causing crosstalk between the image frame and a corresponding image frame in a multiview image system. The method further includes, for a pixel identified as a candidate for causing crosstalk, applying crosstalk correction to the pixel. The method further includes applying a location-based adjustment to the pixel, wherein the location-based adjustment is based at least in part on which of two or more portions of the image frame the pixel is in.
Abstract:
Systems and methods for compressing video data are provided. The method includes segmenting a video frame, selecting a coding mode, and encoding. The segmenting includes segmenting the video frame of the video data into a sequence of coding blocks. The selecting includes selecting the coding mode from a plurality of coding modes. The selecting of the coding mode is based on an allowable bit budget and occurs for each coding block. The encoding includes encoding each coding block based on the coding mode. The allowable bit budget varies according to a bit utilization of prior encoded coding blocks and varies such that the video frame does not exceed a specified compression ratio.
Abstract:
In one example, a method includes identifying a pixel in an image frame that is a candidate for causing crosstalk between the image frame and a corresponding image frame in a multiview image system. The method further includes, for a pixel identified as a candidate for causing crosstalk, applying crosstalk correction to the pixel. The method further includes applying a location-based adjustment to the pixel, wherein the location-based adjustment is based at least in part on which of two or more portions of the image frame the pixel is in.
Abstract:
In one example, a method includes identifying a first set of pixels in co-located pairs in a corresponding pair of multiview image frames for which the co-located pairs have a disparity between the pixels that is greater than a selected disparity threshold. The method further includes identifying a second set of pixels in at least one of the image frames that are within a selected distance of an intensity transition greater than a selected intensity transition threshold. The method further includes applying crosstalk correction to pixels that are identified as being in at least one of the first set and the second set.
Abstract:
An apparatus and method are described for filtering noise internally within a video encoding framework. In various embodiments of the invention, an in-loop noise filter is integrated within an encoding device or framework that reduces noise along a motion trajectory within a digital video signal. This integration of in-loop noise reduction allows both noise filtering parameters and encoding parameters to be more easily related and adjusted. The in-loop noise filter leverages characteristics of digital video encoding processes to reduce noise on a video signal and improve encoding efficiencies of a codec.
Abstract:
A method and apparatus for receiving and processing digitized video data in a discrete cosine transform (DCT) domain exploits the orthogonality of a convolution function along with the data sparseness present in the DCT domain. In a preferred method, the convolution function is applied to vectors associated with a plurality of input video data frames in consideration of an orthogonal characteristic of the convolution function. More specifically, cross-products of the input vectors which would yield non-zero output vectors are identified and weighting factors for the cross-products are determined in consideration of this orthogonality. An output video data frame is generated from the non-zero output vectors and the weighting factors. A convolution operation based upon the disclosed method and aparatus is suitable for chroma-keying as well as other video or audio blending applications.
Abstract:
Multiplier-free implementation of an approximation of the DCT used in image and video processing. In accordance with the primary aspect of the present invention, image and video processing is done with no multiplications and a fewer number of operations through the application of a modified Arai, Agui, and Nakajima (AAN) scheme for eight-point DCT.