Abstract: A video communication unit (405) includes a video input (415) for receiving an un-watermarked video or image signal transmission having a number of video or image frames (110, 120, 130, 140), wherein each video or image frame includes a number of bit planes, the video input (415) being operably coupled to a processor (410). The processor (410) splits at least one bit plane (116) from each of at least two video or image frames (205, 210) into a first and second portion. The processor combines (235, 242,232,245) a second portion of the at least one bit plane of a first frame with a first portion of the at least one bit plane of a second frame to apply a watermark bit to the video or image signal transmission. A video communication system and methods of detecting a tampered area and visually labelling the tampered area are described. This enables fraudulent tampering of images and video to be detected, and the location of such tampering to be revealed to users of the material.

Abstract: A method (500) for segmenting an image comprises the step of identifying (502) one or more regions in the image. The method further comprises the steps of applying a single embedded surface for a Level Sets representation of said image; and performing region control logic (504) to enable said Level Sets, representation to manipulate one or more region boundaries in order to segment said image. This provides a method by which unsupervised image segmentation can be performed on an arbitrary number of classes/objects in the image.

Abstract: A video communication unit (405, 450) comprising a video input (415) for receiving a video signal transmission having a number of video or image frames, wherein each video or image frame includes a number of bit planes, the video input being operably coupled to a processor, the video communication unit characterised by said processor (410, 460) replicating at least one bit plane in at least two video or image frames to provide a tamper detection means of the video or image signal transmission. This enables fraudulent tampering of images and video to be detected, and the location of such tampering to be revealed to users of the material.

Abstract: A method for characterising texture or a texture-like region in an image includes the steps of obtaining saliency values (104) of an image or set of images and applying a threshold to the saliency values (108), to remove the less salient features. A three dimensional shape, for example a cuboid of a predefines size, is generated (210) and saliency space sampled by moving the cuboid across spatial dimensions of the saliency space. An estimation of z probablility density function of scales within that sample space is generated and texture or a texture-like region in the saliency space is characterised using the estimation. This provides a method by which texture can be classified within an image to aid image interpretation. In particular, the texture is classified independent of scale, orientation and illumination. The method is particularly useful for texture classification problems where: the scale is unknown, the scale may vary, or a general scene description is required.

Abstract: Apparatus and methods for controlling the amount of data used to transmit still images during the transmission of a video sequence from a first to a second location are disclosed. The apparatus of one embodiment comprises encoding means (105) arrange for intraframe encoding still images for transmission and intraframe encoding part or all of selected video sequence frames, calculating means (106) for determining the data size of intraframe encoded video sequence frames and control means (107) for controlling intraframe encoding of still images for transmission in dependence on the determined intraframe encoded size of a previous video sequence frame. The system can be operated in a way so as to remain H.263 compliant. Other embodiments control the data size by adjusting the quantization used for each Macroblock and by reprocessing each Group of Blocks until a desired data size is reached.