摘要:
A method for coefficient bitdepth limitation in an encoder and/or bitstream generation apparatus including the steps of (A) generating one or more residual block coefficients in response to a video signal and one or more coding parameters and (B) manipulating the one or more coding parameters such that the one or more residual block coefficients are prevented from having values greater than a bitdepth of the video signal plus a predefined number of bits.
摘要:
A method for image decoding is disclosed. The method generally includes the steps of (A) receiving from a medium (1) an encoded signal and (2) transform data comprising at least one of (i) encoding statistics embedded in the encoded signal, (ii) encoding information and (iii) pre-processing information, wherein (a) the encoding statistics are created by an encoder in encoding an intermediate input signal to create the encoded signal, (b) the encoding information is producible by the encoder in the encoding and (c) the pre-processing information is producible by a pre-processor in converting an image input signal into the intermediate input signal, (B) generating an intermediate output signal by decoding the encoded signal and (C) generating an image output signal by processing the intermediate output signal in response to the transform data.
摘要:
A video encoder including an encoder circuit, a quantizer circuit and a control circuit. The encoder circuit may be configured to generate a plurality of coefficient values and motion vectors in response to a video stream, a first control signal, a second control signal, and a number of quantized values. The control circuit may be configured to (i) generate the first control signal, the second control signal, and a quantizer index signal and (ii) set two or more quantization dead zones and two or more offsets to different values, where the quantization dead zones and the offsets are independently programmable. The quantizer circuit may be configured to generate the number of quantized values in response to the coefficient values, the quantizer index signal, the two or more quantization dead zones and the two or more offsets. A first coefficient value may be quantized using a first quantization dead zone and a first offset. A second coefficient value may be quantized using a second quantization dead zone and a second offset. The first and second quantization dead zones generally have different values. The first and second offsets generally have different values. Quantization calculations determining each quantized value take into account respective quantization dead zones and offsets.
摘要:
A method for deinterlacing a picture is disclosed. The method generally includes the steps of (A) calculating a potential sample at a location interfaced with a first field of the picture by temporal filtering, (B) evaluating a protection condition in a current region around the location after inclusion of the potential sample and (C) calculating an interpolated sample at the location by vertical spatial filtering the first field in response to the protection condition indicating a significant increase in a vertical activity within the current region due to the potential sample.
摘要:
A method for implementing B-frame prediction in video compression comprising the steps of (A) setting a prediction flag (i) “off” if B-frames are used for block prediction and (ii) “on” if B-frames are not used for block prediction, (B) if the prediction flag is off, generating an output video signal in response to an input video signal by performing an inverse quantization step and an inverse transform step in accordance with a predefined coding specification and (C) if the prediction flag is on, bypassing the inverse quantization step and the inverse transform step.
摘要:
The present invention discloses a system and method for rate control of MPEG video streams to achieve a target bit rate in a transcoder at the best visual quality possible. The invention monitors video buffer fullness for selecting the amount of rate reduction necessary to achieve a target bit rate. The invention also utilizes a method for selective requantization of DCT coefficients to assure visual quality.
摘要:
Systems and methods may employ separate image sensors for collecting different types of data. In one embodiment, separate luma, chroma and 3-D image sensors may be used. The systems and methods may involve generating an alignment transform for the image sensors, and using the 3-D data from the 3-D image sensor to process disparity compensation. The systems and methods may involve image sensing, capture, processing, rendering and/or generating images. For example, one embodiment may provide an imaging system, including: a first image sensor configured to obtain luminance data of a scene; a second image sensor configured to obtain chrominance data of the scene; a third image sensor configured to obtain three-dimensional data of the scene; and an image processor configured to receive the luminance, chrominance and three-dimensional data and to generate a composite image corresponding to the scene from that data.
摘要:
Temporally filtering raw image data may include a temporal filter that determines a spatial location of a current pixel and identifies at least one collocated reference pixel from a previous frame. A motion delta value is determined based upon the current pixel and its collocated reference pixel. An index is determined based upon the motion delta value and a motion history value corresponding to the current pixel from the previous frame. Using the index, a first filtering coefficient may be selected from a motion table. Then an attenuation factor may be selected from a luma table based upon the value of the current pixel, and a second filtering coefficient may be determined based upon the selected attenuation factor and the first filtering coefficient. The temporally filtered output value corresponding to the current pixel may then be based upon the second filtering coefficient, the current pixel, and the collocated reference pixel.
摘要:
A device, method, computer useable medium, and processor programmed to automatically generate tone mapping curves in a digital camera based on image metadata are described. By examining image metadata from a digital camera's sensor, such as the light-product, one can detect sun-lit, high-light, and low-light scenes. Once the light-product value has been calculated for a given image, a tone mapping curve can automatically be generated within the sensor and adjusted appropriately for the scene based on predetermined parameters. Further, it has been determined that independently varying the slopes of the tone mapping curve at the low end (S0) and high end (S1) of the curve results in more visually appealing images. By dynamically and independently selecting S0 and S1 values based on image metadata, more visually pleasing images can be generated.
摘要:
A method for encoding an image is disclosed. The method generally includes the steps, of (A) generating a quantization matrix as a function of at least four parameters, (B) optimizing the parameters to maximize a quality metric for encoding the image and (C) encoding the image with the quantization matrix as optimized.