Abstract: An output video signal is derived from an input video signal generated by an image sensor in response to an image formed on only part of the image sensor. The output video signal is derived in response to only the portion of the input video signal generated by the part of the image sensor on which the image is formed. The input video signal additionally includes a portion generated by the part of the image sensor on which the image is not formed. An image signal generating apparatus is provided in which the image sensor is mounted, and which includes a detachably-attached image-forming device. When attached to the image signal generating apparatus, the image-forming device forms the image on the part of the image sensor. A frame of the input video signal is received from the image sensor.

Abstract: An digital video image processing system employs codes of various lengths to encode the luminance information within the digital video images. The inventive method and apparatus divides a video image into non-overlapping regions containing a plurality of pixels with luminance values. Within each region, the method computes the total luminance variation across the region, the direction of greatest luminance change within the region, the base, or lowest, luminance value within the region and the location and type of luminance transition within the region. Depending on the variation of the luminance values within a region and on the quality desired in the decoded image, the computed information is used to encode the luminance values in short, medium, or long codes. The luminance codes may be predetermined and unchanging or they may vary from image to image or within given images.

Abstract: Apparatus for generating a motion vector for use in compressing a digital motion picture signal. The apparatus comprises a circuit for obtaining a primary motion vector with one pixel precision between a picture block of the current picture and a designated block of the reference picture. The apparatus also includes a parallelizing circuit for convening the pixel data of the reference picture into parallel pixel data. The apparatus also includes a search area selecting circuit for selecting the parallel pixel data of a search area of the reference picture in response to the primary motion vector. The search area surrounds and includes the designated block. An interpolating circuit generates parallel half-pixel data from the parallel pixel data of the search area by interpolation in plural parallel paths.

Abstract: A decoder for decoding coded video signals includes a base layer and an enhancement layer which includes a cell loss detector for detecting when cells are missing from the enhancement layer. In such an event the enhancement data from the immediately previous video signal displaced by a displacer according to the current motion vectors provides interpolation data for the missing cells. The interpolation data is added to the decoded base layer as indicated by an adder. The enhancement data is obtained by subtracting the immediately previous base video signal stored in a frame store from the immediately previous decoded video signal stored in another frame store as indicated by a subtracter.