摘要:
A method of signaling additional chroma QP offset values that are specific to quantization groups is provided, in which each quantization group explicitly specifies its own set of chroma QP offset values. Alternatively, a table of possible sets of chroma QP offset values is specified in the header area of the picture, and each quantization group uses an index to select an entry from the table for determining its own set of chroma QP offset values. The quantization group specific chroma QP offset values are then used to determine the chroma QP values for blocks within the quantization group in addition to chroma QP offset values already specified for higher levels of the video coding hierarchy.
摘要:
A method for coding video is disclosed. The method generally includes the steps of (A) receiving a video signal having a series of pictures, each of the pictures having a plurality of blocks, (B) analyzing the blocks to forecast if coding the blocks in a zero-residual coding mode would generate a plurality of artifacts, (C) disabling the zero-residual coding mode for the blocks forecasted to generate at least one of the artifacts and (D) enabling the zero-residual coding mode for the blocks forecasted to generate none of the artifacts.
摘要:
The present disclosure generally relates to systems and methods for image data processing. In certain embodiments, an image processing pipeline may compute noise statistics associated with image data by receiving a frame of the image data having a plurality of pixels. The image processing pipeline may then identify a plurality of portions of the frame of the image data such that each portion of the plurality of portions has a flat surface. The image processing pipeline may then calculate a plurality of gradients for each portion of the plurality of portions, determine one or more dominant gradient orientations for each portion of the plurality of portions, and generate a histogram that represents a plurality of dominant gradient orientations that corresponds to the plurality of portions. After generating the histogram, the image processing pipeline may store the histogram, which may represent the noise statistics, in a memory.
摘要:
Some embodiments of the invention provide a mobile device that captures and produces images with high dynamic ranges. To capture and produce a high dynamic range image, the mobile device of some embodiments includes novel image capture and processing modules. In some embodiments, the mobile device produces a high dynamic range (HDR) image by (1) having its image capture module rapidly capture a succession of images at different image exposure durations, and (2) having its image processing module composite these images to produce the HDR image.
摘要:
Various techniques are disclosed for processing statistics data in an image signal processor (ISP). In one embodiment, a statistics collection engine may be configured to acquire statistics relating to auto white-balance. The statistics collection engine may receive raw Bayer RGB data acquired by an image sensor and may be configured to perform one or more color space conversions to obtain pixel data in other color spaces. A set of pixel filters may be configured to accumulate sums of the pixel data conditionally based upon YC1C2 characteristics, as defined by a pixel condition per pixel filter. Depending on a selected color space, the pixel filters may generate color sums, which may be used to match a current illuminant against a set of reference illuminants with which the image sensor has been previously calibrated.
摘要:
Systems and methods for correcting intensity drop-offs due to geometric properties of lenses are provided. In one example, a method includes receiving an input pixel of the image data, the image data acquired using an image sensor. A color component of the input pixel is determined. A gain grid is determined by pointing to the gain grid in external memory. Each of the plurality of grid points is associated with a lens shading gain selected based upon the color of the input pixel. A nearest set of grid points that enclose the input pixel is identified. Further, a lens shading gain is determined by interpolating the lens shading gains associated with each of the set of grid points and is applied to the input pixel.
摘要:
The present disclosure generally relates to systems and methods for image data processing. In certain embodiments, an image processing pipeline may be configured to receive a frame of the image data having a plurality of pixels acquired using a digital image sensor. The image processing pipeline may then be configured to determine a first plurality of correction factors that may correct each pixel in the plurality of pixels for fixed pattern noise. The first plurality of correction factors may be determined based at least in part on fixed pattern noise statistics that correspond to the frame of the image data. After determining the first plurality of correction factors, the image processing pipeline may be configured to configured to apply the first plurality of correction factors to the plurality of pixels, thereby reducing the fixed pattern noise present in the plurality of pixels.
摘要:
Various techniques are provided for processing image data acquired using a digital image sensor. In accordance with aspects of the present disclosure, one such technique may relate to the processing of image data in a system that supports multiple image sensors. In one embodiment, the image processing system may include control circuitry configured to determine whether a device is operating in a single sensor mode (one active sensor) or a dual sensor mode (two active sensors). When operating in the single sensor mode, data may be provided directly to a front-end pixel processing unit from the sensor interface of the active sensor. When operating in a dual sensor mode, the image frames from the first and second sensors are provided to the front-end pixel processing unit in an interleaved manner. For instance, in one embodiment, the image frames from the first and second sensors are written to a memory, and then read out to the front-end pixel processing unit in an interleaved manner.
摘要:
A method to control weighted prediction for video compression. The method comprises (A) generating statistics based upon analysis of a plurality of video frames, (B) detecting a fade condition based upon the statistics, (C) generating one or more estimated weighted prediction parameters based upon the statistics when the fade condition is detected and (D) encoding the plurality of video frames. The encoding takes into account the estimated weighted prediction parameters when generated.
摘要:
A method for deinterlacing a picture is disclosed. The method generally includes the steps of (A) generating a plurality of primary scores by searching along a plurality of primary angles for an edge in the picture proximate a location interlaced with a field of the picture, (B) generating a plurality of neighbor scores by searching for the edge along a plurality of neighbor angles proximate a particular angle of the primary angles corresponding to a particular score of the primary scores having a best value and (C) identifying a best score from a group of scores consisting of the particular score and the neighbor scores to generate an interpolated sample at the location.