Abstract: A system and method disposed to enable real-time creation and manipulation of digital media within a conventional personal computer environment without dedicated hardware assistance is disclosed herein. In particular, one disclosed method is directed to generating a compressed video output signal using a computing device. The method includes decoding a previously compressed first digital video bit stream to obtain a first decoded digital video signal. The first decoded digital video signal is mixed with a second digital video signal in order to produce a mixed video signal. In addition, the mixed video signal is recompressed so as to form the compressed video output signal wherein the mixing and recompressing are performed by the computing device in substantially in real-time.

Abstract: The present invention relates to a method enabling real-time conversion of the analog video signals from a charge coupled element into digital half-tone data which can be printed on a printer or displayed on a display screen and to a converting device which is developed for use with such method.The method according to the present invention serves six primary functions as follows:1. realization of half-tone patterns and regeneration of gray scales;2. half-tone models of high compression ratio;3. method for controlling and adjusting the contrast and brightness;4. half-tone rules for proportional reduction and enlargement;5. direct current regeneration of analog video signals; and6. compensation for uneven illumination.

Abstract: An improved edge extraction technique for use in copying a halftone original to produce a halftone copy is described. The prior art uses a two path system to rescreen a halftone, a filter path to remove the original screen and an edge extraction path to enhance the edges. The final gray scale signal, before rescreening, is the addition of the outputs of the two paths. This invention is an improved edge extraction technique for use in such a system. First, the sign and magnitude of horizontal and vertical edges is computed. Then a root mean square of these values is taken to provide a two dimensional enhancement. Next, the enhancement is tested against certain thresholds to test whether the value is a result of image noise, or whether there is a probability that a small enhancement may be in the wrong direction. Finally, the enhancement is added to the filter path output.

Abstract: In a reprographic system, a method for distinguishing halftone areas from text in an original. The system raster input scanner produces lines of binary data. A predetermined set of bits within a moveable window is inspected and the probability of that particular set of bits being taken from a halftone area of the original is assigned. The window is moved, bit by bit, and line by line, while an accumulation of probability scores is accomplished. Then, the determination, halftone or text, is made for each 32 by 32 bit block, based on a comparison of the accumulation to a predetermined threshold number. Finally, the block decisions themselves are inspected for halftone areas that may have been classified as text because of very high or low density. If surrounding blocks were determined to be halftone, the internal block will be corrected to halftone also.