Abstract: The invention relates to motion estimation and compensation between two given images represented by a polygonal mesh. It provides a solution to the problems of crowding and uncovering of mesh units when the mesh is shifted.

Abstract: A video is first partitioned into video objects. If the video is uncompressed, then the partitioning is done with segmentation planes. In the case where the video is compressed, a demultiplexer is used for the partitioning. Over time, shape features are extracted from each partitioned object. The extracted shape features are combined to determined a temporal resolution for each object over time. The temporal resolutions are subsequently used to encode or transcode the video objects as an output compressed video.

Abstract: The invention relates to the field of video encoders and, more particularly, to an encoding method based on an adaptation of the matching pursuit method to an error texture coding process inside triangular meshes. Said process is restricted, at each iteration of the method, to a specific triangle selected according to a predefined criterion. An optimal strategy for atom positioning inside this triangle then consists either in arbitrarily selecting the geometrical barycenter of the selected triangle as the center of the atoms, or re-using the error energy information for atom center positioning, the Displaced Frame Difference (DFD) energy barycenter inside the selected triangle having the highest energy being in the second case arbitrarily chosen as the center of the atoms.

Abstract: An information processing apparatus may be for use in dividing an image area to extract objects. Frequency related information generating sections (112, 113) may generate frequency related information related to frequencies of respective pixel values based on pixel values of a plurality of pixels comprising an original image and error information. A representative value deciding section (114) may decide a representative value of a pixel value based on the frequency related information. An accumulating section (115) may accumulate the representative value. A replacing section (116) may replace the pixel values of a plurality of pixels comprising the original image with the representative values accumulated in the accumulated section (115), and may store the replaced representative values in a memory (117) as an outputted image.

Abstract: A data processing method processes image data including spatiotemporal locator information which is added. The spatiotemporal locator information represents a spatiotemporal area which is a temporal transition of an object region over a plurality of frames. The method sets a curved surface defined by a periphery of the spatiotemporal area based on the spatiotemporal locator information, calculates time when a reference trajectory crosses the curved surface, determines whether coordinate values of the reference trajectory are inside or outside of the object region in at least one of frames in which the object region exists, and outputs information relating to whether or not the reference trajectory passes the spatiotemporal area.

Abstract: A region data describing method for describing, over a plurality of frames, region data about the region of an arbitrary object in a video, the method specifying the object region in the video with at least either of an approximate figure approximating the region or characteristic points of the region, approximating a trajectory obtained by arranging position data of the representative points or the characteristic point in a direction in which frames proceed with a predetermined function and describing the parameter of the function as region data. Thus, the region of a predetermined object in the video can be described with a small quantity of data. Moreover, creation and handling of data can easily be performed.

Abstract: An encoder includes a segmenter that segments a reference frame, assigning some or all of the pixels of the reference frame to segments based on pixel color values and/or pixel location. A kinetic information generator generates kinetic information that relates regions of a nonkey frame to segments of the reference frame as indicated by the segmentation. A decoder includes its own segmenter that segments at least a part of the reference frame extracted from the compressed video data, thereby eliminating the need for the encoder to include all of the segmentation in the compressed video data. The decoder includes a nonkey frame generator that regenerates a nonkey frame using kinetic information about the nonkey frame from the compressed video data and using at least a part of the segmentation of the reference frame generated by the decoder's segmenter. The encoder segmentation and decoder segmentation can be the same or different.

Abstract: An efficient motion estimation technique for an arbitrarily-shaped video object reduces the number of searches for motion estimation for shape coding and texture coding. The technique can be easily employed in an MPEG-4 encoder for coding Video Object Planes (VOPs). In a pixel loop, an m×m block traverses a reference video image with the video object, and the alpha plane value of each pixel is examined. If the alpha plane values in a block are not all the same, this indicates the block overlaps the object boundary. Accordingly, a shape coding mask value for the coordinate of a reference pixel in the block, such as the top, left pixel, is set to “1”. As the block traverses the reference video image, a shape coding mask that generally follows the shape of the object boundary is developed to define a shaped reference image search area. A texture coding mask is defined similarly when the blocks overlap or are inside the object.

Abstract: A method and system for contour-based motion estimation for use with video images. The invention establishes corresponding contours (404, 414) in two images (402, 412) in a sequence of images, determines a motion vector which includes how the first contour (404) moved to become the second contour (414), and transmits the motion vector of the contour (414) in order to permit accurate display of the second video image (412). Preferably, boundary lines are removed from the contours before a comparison is made. The invention is computationally efficient and economical from a data transmission point of view, while enabling the production of accurate image.

Abstract: A method determines a surface of an object in a sequence of images. The method begins by estimating a boundary of the object in each image of the sequence using motion information of adjacent images of the sequence. Then, portions of each image of the sequence are ordered to produce an ordered sequence of images. The ordered portions are exterior to the estimated object boundary. Edges in each ordered image are filtered using the motion information, and each ordered image of the sequence is searched to locate the filtered edges to form a new boundary outside the estimated boundary. The filtering and searching are repeated, while projecting the new object boundaries over the sequence of images, until the new object boundaries converges to a surface of the object.

Abstract: A method and apparatus for generating a bounding rectangle of a VOP for interlaced scan type video signals, which are capable of accurately generating a bounding rectangle, thereby preventing a color bleeding from occurring in the field-based chrominance shape subsampling. The method includes bounding rectangle formation step of forming a bounding rectangle of a video object plane in such a fashion that the bounding rectangle contains an object therein, based on input luminance shape information, optimum setting determination step of determining whether or not a spatial reference point of the bounding rectangle is positioned on an x-y coordinate of coordinate value (2m, 4n) (m and n=0, 1, 2, 3, 4, . . .

Abstract: Method, system and computer program product are provided for dynamically determining group of picture (GOP) size as a function of picture change activity within a sequence of video frames. Image statistics on one or more intraframe characteristics of the sequence of video frames is compared to a preset threshold for deciding whether to continue within an existing GOP or to begin a new GOP. A frame of the sequence of video frames is intra-coded, and each of a variable number of subsequent frames is bi-directionally predictive-coded (B). Each B frame subsequent to the I frame is encoded employing forward prediction motion estimation only from the I frame. When a predefined picture degradation occurs, a new GOP is initiated. One example of an intraframe characteristic to be monitored is the number of intra-coded macroblocks within each B coded frame. This number is compared against a threshold number, which may be a percentage of the total number of macroblocks within the frame.

Abstract: A method represents a shape of an object in an image. Portions of the image interior to a boundary of the object are ordered. A medial axis for the ordered portions of the image is derived. The medial axis is segmented to produce an ordered tree. The ordered tree is transformed to a partial ordered tree to represent the shape of the object.

Abstract: Measures for a motion compensation are combined with an image segmentation in four modes. In a first mode, a current picture is image-segmented, before an estimation of a relative motion between a segmented region of the current picture and a corresponding region of a reference picture. In a second mode, a relative motion is estimated between a minute piece of a current picture and a corresponding minute piece of a reference picture, to be employed as a character parameter for an image segmentation. In a third mode, a relative motion is estimated between a sub-region of an image-segmented region and a corresponding small region, to be employed as a character parameter for a resegmentation. In a fourth mode, a relative motion between minute pieces is estimated to provide an additional character parameter for an image segmentation to be performed on a current picture, before a reestimation of a relative motion between an estimated region and a corresponding region.

Abstract: This invention relates to motion compensated (MC) coding of video and to a MC prediction scheme which allows fast and compact encoding of motion vector fields retaining at the same time very low prediction error. By reducing prediction error and number of bits needed for representation of motion vector field, substantial savings of bit rate are achieved. Reduction of bit rate needed to represent motion field is achieved by merging segments in video frames, by adaptation of motion field model and by utilization of motion field model based on orthogonal polynomials.