Abstract: A vertical black line removal system (VBLR) is adapted to remove unwanted vertical lines produced on scanned document images by dust or other particles on the imaging apparatus. The VBLR system, placed in a document scanner after the binarization equipment, creates a stored histogram table including the difference values of “1” or “0” for the first and second image data. A vertical black line search processor compares each histogram value in the histogram table with a predetermined threshold value such that when the histogram value is greater than the threshold value the histogram value and the image address indicating the location of defect are stored in memory.

Abstract: A document scanner for producing any combination of color or grayscale or bi-tonal document images having a selectable range of resolutions is provided that maximizes image production speed by minimizing the processing required to produce the particular type of images selected. The scanner includes an imaging camera including a high-resolution grayscale CCD sensor in combination with lower resolution red, green, and blue CCD sensors. The scanner further includes an image processing circuit for processing data generated by the grayscale and color CCD sensors into any combination of color, grayscale, or bi-tonal document images having high or low resolution. High-resolution color images are produced by superimposing the high-resolution grayscale image generated by the grayscale sensor with the lower resolution color images generated by the color CCD sensors. The image processing circuit may also produce high or low resolution, color, grayscale or bi-tonal images when selected at respectively lower bandwidths.

Abstract: An image sensor device comprising a silicon substrate having a plurality of CMOS circuit formed thereon, including a pixel array having a plurality of rows and a plurality of columns, a row addressing circuit operatively connected to each the pixel array and the timing control circuit, the row addressing circuit having a row bus that provides address lines to each row in the pixel array, a column addressing circuit, a pixel timing circuit, a timing control logic block, a signal processing circuit, and an interface circuit coupled to external computational means for provision of address and control signals to the sensor device, the interface circuit being operatively coupled the timing control logic, the pixel timing circuit, the row addressing circuit and the column addressing circuit.

Abstract: A vertical black line removal system (VBLR) is adapted to remove unwanted vertical lines produced on scanned document images by dust or other particles on the imaging apparatus. The VBLR system, placed in a document scanner after the binarization equipment, creates a stored histogram table including the difference values of “1” or “0” for the first and second image data. A vertical black line search processor compares each histogram value in the histogram table with a predetermined threshold value such that when the histogram value is greater than the threshold value the histogram value and the image address indicating the location of defect are stored in memory.

Abstract: A document scanner for producing any combination of color or grayscale or bi-tonal document images having a selectable range of resolutions is provided that maximizes image production speed by minimizing the processing required to produce the particular type of images selected. The scanner includes an imaging camera including a high-resolution grayscale CCD sensor in combination with lower resolution red, green, and blue CCD sensors. The scanner further includes an image processing circuit for processing data generated by the grayscale and color CCD sensors into any combination of color, grayscale, or bi-tonal document images having high or low resolution. High-resolution color images are produced by superimposing the high-resolution grayscale image generated by the grayscale sensor with the lower resolution color images generated by the color CCD sensors. The image processing circuit may also produce high or low resolution, color, grayscale or bi-tonal images when selected at respectively lower bandwidths.

Abstract: An image sensor device comprising a silicon substrate having a plurality of CMOS circuit formed thereon, including a pixel array having a plurality of rows and a plurality of columns, a row addressing circuit operatively connected to each the pixel array and the timing control circuit, the row addressing circuit having a row bus that provides address lines to each row in the pixel array, a column addressing circuit, a pixel timing circuit, a timing control logic block, a signal processing circuit, and an interface circuit coupled to external computational means for provision of address and control signals to the sensor device, the interface circuit being operatively coupled the timing control logic, the pixel timing circuit, the row addressing circuit and the column addressing circuit.

Abstract: A dual range A/D converter includes a gain matching circuit for balancing the upper end of the transfer curves of the level-dependent dual A/D signal paths of the converter so as to control crossover between the paths. One path (high gain path) is provided with signal gain that is a nominal multiple of gain applied to the other path (low gain path). A digital comparator compares the digital code word output of flash A/D converters included in the respective paths, with the output from the high gain path being scaled down to correspond to the output from the low gain path. If a difference is detected, the upper ladder reference of the flash converter in the low gain path is adjusted until the respective gain difference becomes substantially an exact multiple. When this matching is combined with black level correction, which equalizes the lower end of the transfer curves, a fully self-calibrating dual range A/D converter is obtained.

Abstract: The apparatus and method of the present invention operates upon the problem of contouring that is encountered in the digital image processing field. The preferred apparatus embodiment of the invention forms quantizing steps that vary in size during the processing of signals in order to minimize contouring effects. The embodiment includes a transforming function block for receiving digital input signals each representing a magnitude value requiring quantization, the transforming function block provides an output gain value that is a function of the magnitude of the value of each received digital input signal. A quantizer is provided for receiving the digital input signals and for performing quantizing steps on the digital input signals to provide a multibit quantized digital signal. A first randomizer is used to randomize the least significant bits of the multibit quantized digital signal when the output gain value is less than or equal to threshold value.

Abstract: A method and apparatus for signal companding is disclosed that incorporates a log-offset companding technique to provide both a high bandwidth over the dynamic range of the signal being processed as well as temperature stability. In addition, the incorporation of log-offset companding technique provides the capability of generating a family of transfer curves. The ability to provide a family of transfer curves is particularly useful, for example, in telecine machines adapted to scan more that one type of film.

Abstract: A skip-field guard-bandless video tape recorder records and plays back adjacent tracks on a video tape with two closely adjacent heads of opposing head gap azimuth angles (to suppress cross-talk), only during alternate (odd) half-rotations of the head drum. Unavoidable cross-talk of synchronization pulses from adjacent tracks does not create visible interference or timing errors during playback by virtue of a special offset angle .theta..sub.1, between the adjacent recording heads, proportional to the linear offset distance between adjacent tracks. During playback, skipped fields are "filled-in" by a repetition of each recorded field through a second (duplicate) pair of closely adjacent heads of opposing azimuth positioned to retrace the recorded tracks during the other alternate (even) half-rotations of the head drum. An offset angle .theta..sub.2 between the two head pairs (i.e.