Abstract: The present invention relates to a hierarchical hybrid shot change detection method in MPEG-compressed video circumstances, wherein the method according to the present invention comprises: detecting a shot change candidate region, by hierarchically applying a global color distribution difference among the frames by the color histogram; detecting an abridged shot change candidate region by using the difference of the global color histogram difference among adjacent I, P frames after additionally decoding P frames existed in the detected candidate region; decoding B frames within a abridged shot change detection candidate region at a macro block level in a sequence of the B frames sharing adjacent two anchor frames; determining a distribution characteristic of an intra coded block and a reference pattern type of each B frame in the region; and detecting a hard cut by using the distribution characteristic and reference type.

Abstract: In order to generate, starting from an input MPEG bitstream, an output MPEG bitstream having at least one entity chosen among syntax, resolution, and bitrate modified with respect to the input bitstream, first portions and second portions are distinguished in the input bitstream, which respectively substantially do not affect and do affect the variation in bitrate. When at least one between the syntax and the resolution is to be modified, the first portions of the input bitstream are subjected to the required translation, then transferring said first portions subjected to syntax and/or resolution translation to the output bitstream. When the resolution is left unaltered, the second portions are transferred from the input bitstream to the output bitstream in the substantial absence of processing operations. When the resolution is changed, the second portions of the input bitstream are subjected to a filtering in the domain of the discrete cosine transform.

Abstract: To decrease costs in decoding a digital image signal. An image signal decoding apparatus stores forward reference frame data to be used for a decoding process in frame memories of a main memory provided in a common division, and also stores the frame data highly likely to be used for a motion compensation process in a motion compensation memory provided in a decoding processing division. Accordingly, it is possible, by sharing the main memory, to decrease manufacturing costs of the image signal decoding apparatus compared with the cases of providing dedicated frame memories for storing a current frame data and a forward reference frame data inside the decoding processing division respectively. In addition, it is possible to reduce power consumption during a decoding process compared with the cases of providing the dedicated frame memories.

Abstract: An experimental design for motion estimation in video compression that reduces the number of search locations within a search window by selecting the search locations from a predefined orthogonal table. The search locations are then compared with a reference block to generate match-values that are used to generate level-values reflecting dispositional relationships of the search locations and the relative magnitudes of the match-values. A preliminary motion vector is generated according to the relative magnitudes of the level-values. Candidate results are also generated based on the match-values. A final motion vector is generated by applying predetermined formulas to the level-values and altering the preliminary motion vector according to the candidate results when indicated to do so by the results of the formulas.

Abstract: Still picture images are encoded and transmitted at reduced rates using the MPEG-2 standard. Video frames are captured for processing at a still picture capture rate that is lower than the video input frame rate. The captured frames are compressed as Intra frames at the input frame rate. Selected ones of the compressed frames are inserted in the MPEG-2 transport stream for communication to a decoder at a still picture repetition rate which is no less, in frames per second, than the capture rate.

Abstract: With the new plasma display panel technology new kinds of artifacts can occur in video pictures. These artifacts are commonly described as dynamic false contour effect, since they correspond to disturbances of grey levels and colors in the form of an apparition of colored edges in the picture when the observation point on the PDP screen moves. According to the invention such an artifact is compensated by analyzing the motion in the pictures assigning to each block of a picture a corresponding motion vector and performing a re-coding step in which a sub-field code word entry of a current pixel are calculated. For this purpose the motion vector is defined to point from a pixel in a previous picture to a pixel in the current picture. The sub-field code word entries for a current pixel (P8) are determined by dragging sub-field entries of the pixels lying on the motion vector trajectory.

Abstract: When all frames, which are used for reference, are stored, vector retrieval means 13 find correlation with a reference frame. Compression type determination means 14 compare a predictive error of the found vector position and an average deviation within the frame, and select the compression type with high compression efficiency. Compression mode determination means 15 select anyone of the compression process at the time of the high-speed mode and the compression process at the time of the normal mode based on the compression type. In the compression process at the time of the high-speed mode, for the macro block the difference between it and the predictive block is not taken in motion predictive means 16, it is converted into a frequency component in frequency conversion means 17, is quantized in quantization means 18, and is coded by the compression in variable-length coding means 23 to output the compression code from output means 24.