Abstract: A teletext memory arrangement is organized as three memory sections, a first memory section (sequential memory 6a), a second memory section (sub-page memory 6b), and a third memory section (pipeline memory 6c). The sub-page memory (6b) and the sequential memory (6a) are dynamically dependent in the sense that whenever it is determined that the number of sub-pages of a user requested page N is less than the number of memory storage positions that make up the sub-page memory (6b), the unused memory storage positions of the sub-page memory (6b) are used to store higher order pages of the requested page N, thereby serving as a dynamic extension of the sequential memory. The third memory section (pipeline memory 6c) is used to store the K most recently requested teletext pages (the viewing history). The viewing history is maintained in a non-volatile memory (9) which is communicatively coupled to the teletext memory.

Abstract: An SNR and spatial scalable video coder uses standards compatible encoding units (303, 310, 320) to produce abase layer encoded signal (130) and at least two enhanced layer encoded signals (314, 325). The base layer and at least the first enhanced layer are produced from a downscaled signal (200). At least one additional enhanced layer is produced from an upscaled signal (321). Advantageously, a single encoder/decoder pair can be used, in combination with feedback, switches, and offsets to produce all layers of the scalable coding. Modular design allows an arbitrary number of either spatial or SNR scalable encoded layers and error correction for all but the last layer. All encoders operate in the pixel domain. Decoders are also shown.

Abstract: The present invention relates to method for spatial up-scaling of an original video frame comprising p rows and q colums of pixels, where p and q are integers. Said up-scaling method comprises a step of constructing high-low (HL), low-high (LH), and high-high (HH) virtual spatial frequency subbands comprising p rows and q colums of pixels from the use of high-pass filtering of the original video frame, considered as a low-low spatial frequency subband (LL), in horizontal, vertical, and both directions, respectively. Said up-scaling method further comprises a step of applying an inverse wavelet transform (IWT) to the constructed subbands and to the original video frame in such a way that an up-sampled version of the original image is obtained.

Abstract: A teletext receiver arrangement comprises a receiver for receiving broadcast data including teletext data elements through a broadcast channel (8,9); a teletext processor (12,13) for extracting the teletext data elements from the broadcast data; and processor (13) for generating a video signal encoding a customized teletext page from the teletext data elements according to a set of instructions. The teletext receiver arrangement comprises all interface (20) for establishing a connection to a server (7) through an interaction channel (21), and is programmed to download a piece of computer code implementing the set of instructions from the server (7) through the interaction channel (21).