Abstract: A method and apparatus control bit rates used in a moving pictures encoder, such as an MPEG standard encoder. A sequence of moving pictures is divided into segments each of which comprises one or more groups of pictures. A constant overall bit rate is specified for the sequence of pictures, but variable bit rate encoding used within each segment. A difference between the number of bits allocated for encoding the segment and the actual bits used for encoding is determined, and the difference distributed over one or more subsequent segments.

Abstract: Method of compressing a digital image signal in which a first quantization step set, which is unique for a given segment, is determined so that the number of bits needed to encode the quantized data corresponding to this segment is greater than a target value. This first quantization step set then being modified, as a priority, for the blocks of the segment for which the gain, in the course of this modification, on the reduction of the number of bits needed to encode the quantized data corresponding to the segment to which it belongs, is the highest. This modification is carried out, on as many blocks as is necessary for the number of bits of this segment to be less than or equal to the target value. Device to implement this method.

Abstract: A method of transferring sets of video line data and macroblock data, includes the steps of determining a macroblock period and a video line period longer than the macroblock period, dividing each set of video line data to be transferred within the video line period into two or more portions according to the difference between the determined macroblock period and video line period, aligning a burst transfer of each of the portions of the divided set of video line data and each set of macroblock data to the macroblock period, and initiating the burst transfer of the sets of video line data and macroblock data at macroblock period intervals.

Abstract: A macro-block (MB) quantization reactivity compensation method for a video encoder is provided. The method calculates a reference picture quantization value based on a calculated picture complexity. This predicted reference quantization is combined with the bits-used reactive MB reference quantization value to determine the final MB reference quantization value. This MB reference quantization value is also made adaptive to the VBV buffer fullness, as well as to the predicted change of the current picture complexity. A video encoder and an article of manufacture that comprises computer readable program code for execution of the method are also provided.

Abstract: A method for adaptive pre-filtering is disclosed, comprising the steps of: extracting tuning parameters from video encoding process; processing these tuning parameters to generate control parameters representative of the properties of the video data processed; coupling the control parameters to filter response; generating filter coefficients on selected filter response; and filtering the video data with the filter coefficients before video encoding. The filtering of video data is thus adapted to at least one or more tuning parameters of the video data and the encoding process. The filtering decreases the complexity of encoding by attenuation of high frequency, effectively decreasing the quantization step and reducing compression artifacts.

Abstract: A method and system for digital video noise reduction which includes a picture analyser (103) for analysing pictures in a video sequence to determine the amount of moving regions therein, a noise level detector (102) for estimating the noise level (N) in the video sequence, a filtering level estimator (105, 103) for determining a maximum filtering level (L) for each picture based on the amount of moving regions and the estimated noise level (N) and a spatial filter (106) and a temporal filter (107), the temporal filter being coupled to the filter level estimator for controlling the level of filtering of each picture in the sequence in accordance with the maximum filtering level.

Abstract: A method and apparatus control bit rates used in a moving pictures encoder, such as an MPEG standard encoder. A sequence of moving pictures is divided into segments each of which comprises one or more groups of pictures. A constant overall bit rate is specified for the sequence of pictures, but variable bit rate encoding is used within each segment. A difference between the number of bits allocated for encoding the segment and the actual bits used for encoding is determined, and the difference is distributed over one or more subsequent segments.

Abstract: A method includes receiving image information representing at least one image. The image information defines multiple pixels in the at least one image. The method also includes identifying filter weights associated with the pixels. The filter weights are based on edge contents of at least a portion of the at least one image. In addition, the method includes filtering the image information using the identified filter weights.

Abstract: A method includes identifying a pair of image data blocks separated by a boundary. The image data blocks include image information defining multiple pixels in at least one image. The method also includes identifying at least one filter length based on edge contents of at least some of the pixels in the at least one image. In addition, the method includes filtering at least some of the pixels in the pair of image data blocks along the boundary using the at least one identified filter length.

Abstract: A method and apparatus for noise level estimation in a digital video signal, the apparatus including a pixel activity detector that produces a mean pixel activity level for each picture in the video signal, a contrast analyzer that produces a contrast activity level for each picture and a noise level calculator that is coupled to the activity detector and contrast analyzer to produce an estimated noise level by offsetting the contrast activity level from accumulated output of the activity detector.

Abstract: A method and apparatus for encoding pictures of a moving pictures sequence according to an overall target bit-rate, such as in a MPEG video encoder. Each picture has an assigned picture coding type for which a quality factor is adaptively determined according to past bit usages, so that bits can be adaptively allocated amongst picture types for optimizing visual quality of the encoded pictures.

Abstract: An apparatus, method, and computer program encode video information. The apparatus, method, and computer program use a global deviation for previously encoded video information to encode additional video information. The global deviation represents a difference between (1) at least one expected characteristic of the previously encoded video information if encoded at a target bit-rate and (2) at least one actual characteristic of the previously encoded video information. The apparatus, method, and computer program use the global deviation to adjust at least one encoding parameter, which is then used to encode the additional video information.

Abstract: A method and apparatus of encoding digital video, for example according to the ISO/IEC MPEG standards (ISO/IEC 11172-2 MPEG-1 and ISO/IEC 13818-2 MPEG-2), which employs a local motion estimator for determining respective local motion vectors for groups of adjacent macroblocks in a picture. A local motion vector is determined for each row of macroblocks in a picture from the motion vectors of the macroblocks in that row. Then, for macroblocks in the corresponding row of a subsequently coded picture, the local motion vector can be used to select the search window used for determining the motion vectors. The local motion estimator improves search range and accuracy of macroblock motion vector detection without increasing the search window accessing bandwidth and caching requirement, and computation lode of searching.

Abstract: A method of processing video data to detect field characteristics of the data, including processing pixel values of the data to obtain differences between the values of two successive fields of the data, processing the difference values to detect interlace patterns in the successive fields, determining if the successive fields belong to a progressive frame based on detection of the interlace patterns, and generating a progressive frame output indicating that a progressive frame has been detected. The pixel values of the first field of the successive fields and a subsequent field to the successive fields are processed to obtain further difference values to determine if the subsequent field is a redundant field, when the progressive frame output is generated.

Abstract: Apparatus for depacketizing and aligning packetized input data. Data processing means receives the input data via an input memory and detects, identifies and determines payload size of a data packet of the input data. The data processing means generates a payload size signal indicative of the size of the payload. A word formatter receives units of the payload from the input memory and gathers and aligns these to form data words. A payload counter controls flow of input data from the input memory to the word formatter in accordance with the payload size signal. An input buffer receives the data words from the word formatter, stores these and transfers them to the data processing means for effecting data processing.

Abstract: A processor for enhancing an input luminance signal including: a means for calculating a chroma edge value associated with the input luminance signal; a means for measuring a luminance gradient associated with the input luminance signal; a peaking filter for processing the input luminance signal; a gain adjustment circuit having a gain function that is adjustable relative to the calculated chroma edge value, the gain adjustment circuit being operable to adjust the magnitude of the output of the peaking filter wherein: in a first range of luminance gradients, the output is an attenuated version of the input; in a second range of luminance gradients the output is directly proportional to the input; in a third range of luminance gradients, the output is inversely proportional to the input; wherein said enhanced luminance signal is the sum of the input and output of the peaking filter.

Abstract: A method of colour saturation compensation in a video signal is disclosed. The method includes the steps of: processing a luminance signal component of the video signal; determining whether the processing of the luminance signal results in a change in chrominance saturation; if the step of determining reveals that the chrominance saturation has changed, applying a chrominance compensation signal to the chrominance signals to counteract the effects of chrominance saturation, wherein said step of applying a compensation signal include the steps of: generating a compensation signal which is dependent on hue and luminance ratio (output luminance signal/input luminance signal). Apparatus for performing the method is also disclosed.

Abstract: This method and apparatus described herein imposes masking factors to the determined quantization step sizes of macroblocks of a video sequence such that encoding efficiency is increased. A conditional masking method can be used to take advantage of the fact that P-pictures are more important than B-pictures in terms of motion and scene updates as coding noise in such updates are likely propagated by P-pictures. The masking can be applied conditionally to motion/scene update regions of a picture such that coding noise is reduced and therefore bits are saved from less propagation of this noise. Before encoding each macroblock of a picture from an input video sequence, a video encoder with conditional masking determines if the macroblock type belongs to a significant motion or scene update region. A conditional masking factor is then determined for the macroblock based on the determined macroblock type and the picture coding type.

Abstract: A method and apparatus for encoding digital video utilizing a single pass variable bit rate encoding procedure. An encoding quality is set and the bit rate for encoding blocks or frames in the sequence of moving pictures is determined to achieve the selected quality according to the complexity of the video sequence. The bit rate is constrained by predetermined upper and lower bit rate limits.

Abstract: Method of compressing a digital image signal in which a first quantization step set, which is unique for a given segment, is determined so that the number of bits needed to encode the quantized data corresponding to this segment is greater than a target value. This first quantization step set then being modified, as a priority, for the blocks of the segment for which the gain, in the course of this modification, on the reduction of the number of bits needed to encode the quantized data corresponding to the segment to which it belongs, is the highest. This modification is carried out, on as many blocks as is necessary for the number of bits of this segment to be less than or equal to the target value. Device to implement this method.