Techniques and tools for signaling the number of reference fields for an interlaced forward-predicted field are described. For example, a video decoder processes a first signal indicating whether an interlaced forward-predicted field has one or two reference fields for motion compensation. If the first signal indicates the interlaced forward-predicted field has one reference field, the decoder processes a second signal identifying the one reference field from among the two reference fields. On t...

A motion vector detection method includes extracting a first block from the m-th picture, extracting second blocks having a large correlation with respect to the first block from a (m+n)-th picture ((m+n)>m-th), detecting first motion vectors between the first and second blocks, extracting a third block located in spatially the same position as that of the first block from a (m+i)-th picture ((m+n)>(m+i)>m-th), computing second motion vectors of (n-1)/n times the first motion vectors, e...

During transform-based video compression processing, motion vectors, which are identified during motion estimation and then used during motion-compensated inter-frame differencing, are constrained to coincide with block boundaries in the reference data. Block-based motion vectors have components that correspond to integer multiples of block dimensions. For example, for (8.times.8) blocks, allowable motion vector components are ( . . . , -16, -8, 0, +8, +16, . . . ). Constraining motion vectors i...

An apparatus including a first circuit, a second circuit and a third circuit. The first circuit may be configured to generate a plurality of first motion vectors and first error scores in response to a search of a macroblock of an image. The search generally includes a range of motion vectors of the macroblock. The second circuit may be configured to generate a plurality of second motion vectors and second error scores for a plurality of sub-blocks of the macroblock in response to a set of discr...

An image capture and transmission system includes first and second imaging devices. A timing signal generator produces a timing signal. A common drive circuit operates for driving the first and second imaging devices at equal timings determined by the timing signal. A first signal processor operates for converting an output signal of the first imaging device into first digital video data. A second signal processor operates for converting an output signal of the second imaging device into second ...

A method of selecting a motion vector for use in a motion estimation system in which the motion vector defines movement of a block of pixels between a search window and a reference frame. The method includes the steps of scanning a search window in a fixed order for a suitable match with an area of the reference frame such that each search position within a current row or column of the window is one pixel away from a previous search position, defining a preferred point in the search window, calc...

An encoding and decoding apparatus using a wavelet transformation and motion estimation is disclosed. The apparatus includes an input module for receiving an image data, a wavelet module for wavelet-transforming the image data received through the input module, an estimation/compensation module, a storage module for storing the image data being transmitted from the input module and transmitting the stored data in a request from the respective modules, an output module for outputting one bit stre...

In image encoding methods or systems, first and second motion vectors are determined for the two fields comprising a frame based on a field search. The first and second motion vectors then may be used to determine whether a frame prediction search is necessary. If the difference between motion vectors for the two fields of the frame is less than a threshold, the frame search should be performed. A suitable threshold may be calculated or described in any number of ways, however, in one embodiment...

A process for obtaining information from at least two image frames of a sequence of frames, each of the frames including an array of pixels, each pixel having an amplitude, one of the two frames being designated as a reference frame and the other being a non-reference frame, the process including: (1) defining a set of velocities with which the motion of pixels between the two frames may be modeled; dividing each one of the two frames into plural regions, each region in each one of the two frame...

A high-speed motion retrieval device is provided that certainly unerring motion vector at high speed. The first-stage motion retrieval means 12 retrieves a retrieval range determined by referring to the retrieval result in the previous frame. If a minimum predictive error is smaller than a threshold value, the motion retrieval process is ended at the time the retrieval range has been retrieved. If the minimum predictive error is larger than the threshold value, the second-stage motion retrieval ...