Abstract: A method and an apparatus to encode a series of quantized coefficients of a transform of a block of image data. The transform is such that 0 is the most likely coefficient amplitude and 1 is the next most likely coefficient amplitude. The method includes forming modes for each encountered non-zero amplitude and forming events for the modes in the mode-modified series formed by setting to zero all non-zero amplitudes other than the amplitude defining the mode. An event for modes for amplitudes greater than 1 is a run of none or more zero-valued coefficients followed a non-zero amplitude in the mode-modified series. In one embodiment, a first mode is defined for amplitude 1 wherein an event is a run of none or more zero-valued coefficients followed the amplitude 1 coefficient in the mode-modified series.

Abstract: A universal connector for a memory card comprising a connector body, an ejecting mechanism and a fixing stage. The connector body includes a guiding stage and clamping body on the left and right side thereof. The ejecting mechanism comprises an operation actuator and an ejecting plate. The operation actuator is arranged on the guiding stage located on either the left or right side of the connector body. The fixing stage may be located on either the left or right side of the connector body. The fixing stage is provided with a locking hole and clamping tooth. The clamping tooth is adapted to engage a corresponding clamping body of the connector body to fix the fixing stage to the connector body and position the operation actuator of the ejecting mechanism on either the left or right side of the connector body.

Abstract: An apparatus and method for signal processing employing intraframe and interframe variable prediction transform coding. Images are represented by sequential frames of two-dimensional arrays of digital signals. The digital signals are transformed to form transform coefficients for each frame. Predicted transform coefficients are formed using sets of variable prediction factors. The predicted transform coefficients for each frame are compared with corresponding actual transform coefficients for the frame to form transform coefficient difference signals. The difference signals are processed to control their range of values. The processed difference signals are statistically coded such that the more frequently occurring values are represented by shorter code lengths and the less frequently occurring values are represented by longer code lengths. The coded signals are stored in a buffer memory for transmission.

Abstract: The present invention relates to methods and apparatus for processing signals to remove redundant information thereby making the signals more suitable for transfer through a limited-bandwidth medium. The present invention specifically relates to methods and apparatus useful in video compression systems. Typically, the system determines differences between the current input signals and the previous input signals using mean-square difference signals. These mean-square signals are processed and compared with one or more thresholds for determining one of several modes of operation. After processing in some mode, the processed signals are in the form of digital numbers and these digital numbers are coded, using ordered redundancy coding, and transmitted to a receiver.

Abstract: A dual mode facsimile data compression technique which possesses the advantage of symbol recognition and extended run-length coding methods. In operation, a symbol blocking operator isolates digital raster data representing valid alphanumeric characters and document symbols. The first symbol encoungered is placed in a memory or library and as each new symbol is detected, it is compared with each entry of the library. If the comparison is within a predetermined tolerance, a library identification code representing the symbol is generated and transmitted along with the symbol location coordinates. Otherwise, the new symbol is placed in the library and its digital pattern and location is transmitted. A scoring system determines which elements of the library are to be replaced by new prototypes once the library is filled. Non-isolated symbols are coded by a two-dimensional run-length coding method for transmission.

Abstract: A digital video compression and expansion system and its methods for compressing and expanding digitalized video signals in real time at rates up to NTSC color broadcast rates are disclosed. The system compressor receives digitalized video frames divided into subframes, performs in a single pass a spatial domain to transform domain transformation in two dimensions of the picture elements of each subframe, normalizes the resultant coefficients by a normalization factor having a predetermined compression ratio component and an adaptive rate buffer capacity control feedback component, to provide compression, encodes the coefficients with a minimum redundancy coding scheme and stores them in a first rate buffer memory asynchronously at a high data transfer rate from which they are put out at a slower, synchronous rate.

Abstract: An improved method and apparatus for calculating discrete cosine transform coefficients from a plurality of digitalized data is disclosed. The pipelined processor utilizes two basic types of circuits arranged in five computational stages. Shuffle and add circuits operate upon prearranged data components at the first, second and fourth stages, while shuffle, add and multiply circuits are used at the third and fifth stages.

Abstract: A digital video compression system and its methods for compressing digitalized video signals in real time at rates up to NTSC color broadcast rates are disclosed. The system compressor receives digitalized video frames divided into subframes, performs in a single pass a spatial domain to transform domain transformation in two dimensions of the picture elements of each subframe, normalizes the resultant coefficients by a normalization factor having a predetermined compression ratio component and an adaptive rate buffer capacity control feedback component, to provide compression, encodes the coefficients and stores them in a first rate buffer memory asynchronously at a high data transfer rate from which they are put out at a slower, synchronous rate.