A method of detecting a motion vector in an image coding apparatus, including blocking an input image block to be coded into a plurality of input blocks each consisting of a plurality of pixels; sub-sampling a coded image signal to obtain a coded and sub-sampled image signal; sub-sampling the input image block at a predetermined pixel interval to obtain a sub-sampled input block; searching a primary block most correlated with the sub-sampled input block from the coded and sub-sampled image signal in a predetermined range, to output a primary motion vector which indicates the primary block most correlated with the sub-sampled input blocks; and controlling at least one of a central position of a searching area and a searching pel accuracy in accordance with a type of the primary motion vector, to search a secondary block most correlated with one of the input blocks from a coded image signal, to obtain a secondary motion vector.

Method of detecting a motion vector in an image coding apparatus

A system (26) for stabilizing a video recording of a scene (20, 22, & 24) made with a video camera (34) is provided. The video recording may include video data (36) and audio (38) data. The system (26) may include source frame storage (64) for storing source video data (36) as a plurality of sequential frames. The system (26) may also include a processor (50) for detecting camera movement occurring during recording and for modifying the video data (36) to compensate for the camera movement. Additionally the system (26) may include destination frame storage (70) for storing the modified video data as plurality of sequential frames.

Video stabilization system and method

Method and apparatus are disclosed for deinterlacing of an interlaced video frame sequence using interpolation estimations, such as spatial and temporal interpolations. Interpolations requiring a less accurate estimation of missing pixel values in the frames being deinterlaced, such that an interpolation may be performed with a minimum of error, are performed before interpolations which require a more accurate estimation of missing pixel values for performing an interpolation, such that estimates of missing pixel values are obtained with a minimum of error. Interpolation estimations are weighted in combination for computing approximations of missing pixel values in accordance with the errors associated with the respective interpolations.

Method and apparatus for converting an interlaced video frame sequence into a progressively-scanned sequence

A method and structure for stabilizing a motion image formed using a sequence of successive frames which includes calculating a motion vector field between adjacent frames; forming a motion vector histogram from horizontal and vertical components of the motion vector field; applying a threshold to the motion vector histogram to produce a thresholded motion vector histogram; generating average horizontal and vertical motion components from the thresholded motion vector histogram; filtering the average horizontal and vertical motion components over a number of frames to identify unwanted horizontal and vertical motion components for each of the frames; and stabilizing the image sequence by shifting each frame according to the corresponding unwanted horizontal and vertical motion components.

Automated stabilization method for digital image sequences

A process for converting interlaced frames into progressive frames comprising a change of frame frequency by interpolation and motion compensation, wherein when a motion vector associated with a pixel to be interpolated is non-zero or when the motion vector is zero but the confidence accorded to this vector is less than a given threshold, the interpolation of the pixel of a frame situated temporally between two input frames is carried out by a median filtering pertaining to the values obtained by a first motion compensated linear temporal filter, a second motion compensated linear filter, and a motion compensated median temporal filter.

Process for interpolating progressive frames

In, for example, a motion compensated video standards converter wherein blocks in a first field or frame of a video signal are each compared with a plurality of blocks in the following field or frame of the video signal for deriving motion vectors representing the motion of the content of respective blocks between the first field or frame and the following field or frame, and wherein a correlation surface is generated for each block in the first field or frame, the correlation surface representing the difference between the content of the first block in the first field or frame and the content of each block in the following field or frame with which it has been compared; the minimum difference represented by the correlation surface and differing from the next smallest difference represented by the correlation surface by more than a predetermined threshold value is found to derive a motion vector, the number of motion vectors so derived is averaged (62) over a predetermined number of fields or frames, and the threshold value is varied (67, 68, 69) in dependence on the average.

Motion compensated video standards converter and method of deriving motion vectors

In, for example, a motion compensated video standards converter (Figure 1) wherein blocks in a first field or frame of a video signal are each compared with a plurality of blocks in the following field or frame of the video signal for deriving motion vectors representing the motion of the content of respective blocks between the first field or frame and the following field or frame, and wherein a correlation surface is generated for each block in the first field or frame, the correlation surface representing the difference between the content of the first block in the first field or frame and the content of each block in the following field or frame with which it has been compared; the minimum difference represented by the correlation surface and differing from the next smallest difference represented by the correlation surface by more than a predetermined threshold value is found to derive a motion vector, the number of motion vectors so derived is averaged (62) over a predetermined number of fields or frames, and the threshold value is varied (67, 68, 69) in dependence on the average.

Nicholas Ian Saunders

Papers

Motion compensated video standards converter and method of deriving motion vectors

Motion dependent video signal processing