Abstract:
The present invention relates to a method, system and computer program product for the predictive encoding of digital video sequences. The objectives of the invention are accomplished by dynamically determining the resolution of a current frame being encoded and outputting the determination. The determination process is based on statistical and coding information of a plurality of frames, including at least one previous frame and the current frame. Further, general encoding parameters and the encoding parameters of a current frame at a chosen resolution are determined, wherein the encoding parameter selection step takes into account the determination of the dynamic resolution determination step in determining the encoding parameters.
Abstract:
[0052] A method and apparatus for processing a bitstream in a digital video transcoder is described. In one example, an adjustment factor is determined (408) that relates a number of bits representing a selected frame defined by the bitstream to a target number of bits for the selected frame. An average spatial activity value among sets of video data is associated (410) with the selected frame. A spatial activity value for a selected set of the sets of video data is determined (414). A normalized spatial activity value for the selected set of frequency video data is then computed (416) in response to the average spatial activity value, the spatial activity value, and a function of the adjustment factor. Target bit reduction for each of the sets of video data may be computed using a function of the normalized spatial activity value and the adjustment factor.
Abstract:
Disclosed is a scalable video coding algorithm. A method for video coding includes temporally filtering frames in the same sequence to a decoding sequence thereof to remove temporal redundancy, obtaining and quantizing transformation coefficients from frames whose temporal redundancy is removed, and generating bitstreams. A video encoder comprises a temporal transformation unit, a spatial transformation unit, a quantization unit and a bitstream generation unit to perform the method. A method for video decoding is basically reverse in sequence to the video coding. A video decoder extracts information necessary for video decoding by interpreting the received bitstream and decoding it. Thus, video streams may be generated by allowing a decoder to decode the generated bitstreams, while maintaining the temporal scalability on an encoder-side.
Abstract:
The invention relates to video signal processing such as for TV or DVD signals. Methods and systems for detection and segmentation of local visual space-time details in video signals are described. Furthermore, a video signal encoder is described. The method described comprises the steps of dividing an image into blocks of pixels, calculating space-time feature(s) within each block, calculating statistical parameter(s) for each space-time feature(s), and detecting blocks wherein the statistical parameter(s) exceeds a predetermined level. Preferably, visual normal flow is used as a local space-time feature. In addition, visual normal acceleration may be used as space-time features. In preferred embodiments visual artefacts, such as blockiness, occurring by MPEG or H.26x encoding can be reduced by allocating a larger amount of bits to local image parts exhibiting a large amount of space-time details.
Abstract:
A digital media content (e.g., image, video, audio, etc.) encoder/decoder employs a spatially varying parameter to condition the application of an overlap pre-process and post-process to adjacent transform block edges for the spatial-domain lapped transform. This conditional application of the lapped transform to sub-blocks of the digital media can be signaled on an edge, block, macro-block or other granularity. Further, a restriction on use of the conditional lapped transform based on a frame-level quantization or other bit-rate related parameter minimizes the signaling overhead impact at low bit-rates of coding.
Abstract:
A video encoder (200, 300) and corresponding methods (600, 700) are provided for weighted prediction estimation using a displaced frame difference or differential, the encoder embodying a method (700) for receiving (712) a substantially uncompressed image block, assigning (714) a weighting factor for the image block corresponding to a particular reference picture having a corresponding index, computing (716) motion vectors corresponding to the difference between the image block and the particular reference picture, motion compensating (718) the particular reference picture in correspondence with the motion vectors, multiplying (720) the motion compensated reference picture by the assigned weighting factor to form a weighted motion compensated reference picture, subtracting (722) the weighted motion compensated reference picture from the substantially uncompressed image block, and encoding (724) a signal indicative of the difference between the substantially uncompressed image block and the weighted motion compensated reference picture along with the corresponding index of the particular reference picture.
Abstract:
An error masking method using a moving picture electronic watermark. The method can reduce the operation quantity required for estimating motion vectors and acquire correct motion vectors even in case of high error ratio. The method has the conventional accuracy as the lowest accuracy and the upper layer compatibility with a general-purpose decoder. The digital moving picture signal is area-divided into a plurality of blocks or macro-blocks comprising N x N pixels, and each block or macro-block is subjected to motion-compensation. When obtaining the differential signal from one of the image in the future and in the past, and when obtaining no differential signal, each block or macro-block is transformed through the discrete cosine transform to obtain the discrete cosine transform output. The discrete cosine transform output is quantized to obtain the quantized output. The quantized output is subjected to the variable length encoding to obtain the bit stream. On the other hand, the motion vector is embedded in each block or macro-block as the electronic watermark information, so that the electronic watermark information is used for masking errors during decoding.
Abstract:
Methods and systems are disclosed for a video system. In a first exemplary embodiment, a video system (100) comprises a video processing circuit (105) that receives a picture and provides video compression by using an optimal macroblock mode of operation, the optimal macroblock mode of operation being identified by processing at least one macroblock of the picture, the processing being performed independent of other macroblocks contained in the picture. Additionally, the video processing circuit comprises a mode selection circuit (215) that identifies the optimal macroblock mode of operation by using a rate-distortion model. The rate-distortion model incorporates an overall macroblock mode distortion D that is defined as the sum of D>AC DC
Abstract translation:公开了用于视频系统的方法和系统。 在第一示例性实施例中,视频系统(100)包括视频处理电路(105),其接收图像并通过使用最佳宏块操作模式提供视频压缩,最佳宏块操作模式通过处理至少一个 图像的宏块,处理是独立于包含在图像中的其他宏块执行的。 此外,视频处理电路包括通过使用速率 - 失真模型来识别最佳宏块操作模式的模式选择电路(215)。 速率 - 失真模型包含总体宏块模式失真D,其被定义为由于AC系数导致的D> AC DC <由于DC系数导致的失真。
Abstract:
A method for compressing a sequence of digital images includes: comparing a reference image of the sequence of digital images to a subsequent image of the sequence of digital images. In response to the reference and subsequent images being the same within a predetermined threshold, 1) a count of a number of images discarded is incremented, 2) the subsequent image is discarded, and 3) the comparing step is repeated with a next subsequent image. In response to the reference and subsequent images not being within the predetermined threshold, 1) the count is initialized and 2) the comparing step is repeated using the subsequent image as the reference image. Rather than comparing whole images corresponding portions of the images can be compared and compressed independently.