A data compression apparatus is described having an encoder and a decoder. Data in the form of an N-bit data message from an external data source is received in the encoder and stored in an N-bit memory. Coupled to the memory is a "one's" detector and three arithmetic units. The "one's" detector counts the number of logical "one's" in the N-bit message irrespective of their position in the memory for generating a number Q. The three arithmetic units sum columns of the contents of the memory in three predetermined sequences for generating three numbers A, B and C. The numbers A, B, C and Q are then used to form a P-bit data message, where P is less than N for a sufficiently large N - e.g., for N=256, N/P is approximately 2.8 - for transmission to the decoder. The decoder is provided with an N-bit memory, three arithmetic units and a comparison circuit. Upon receipt of the P-bit data message, Q logical "one's" are stored in the decoder memory. The arithmetic units in the decoder, as in the encoder, sum columns of the contents of the decoder memory in three sequences for generating three numbers A', B' and C'. The numbers A', B', and C' are compared with the numbers A, B and C in the comparison circuit. A shifting circuit controlled by the comparison circuit repetitively shifts the logical "one's" in the decoder memory until A'=A, B'=B and C'=C. When A'=A, B'=B and C'=C, the original N-bit data message is recreated and is available for use by an external utilization apparatus.
A process and data processing system are disclosed for compressing and expanding structurally associated multiple data sequences. The process is particular to data sets in which an analysis is made of the structure in order to identify a characteristic common to a predetermined number of successive data elements of a data sequence. In place of data elements, a code is used which is again decoded during expansion. The common characteristic is obtained by analyzing data elements which have the same order number in a number of data sequences. During expansion, the data elements obtained by decoding the code are ordered in data series on the basis of the order number of these data elements. The data processing system for performing the processes includes a storage matrix (26) and an index storage (28) having line addresses of the storage matrix (26) in an assorted line sequence.
In a data compressing system, a sampling circuit samples an audio signal from a signal generator at a given period, and an A/D converter converts the sampled data into corresponding digital data. A differential circuit differentiates the digital sampled data to produce differential sampled data. The differential sampled data is segmented into sampling data trains each including the number of the sampled data corresponding to the audio signal for one second. The sampled data trains for 100 seconds are added by an adder in a manner that the sampled data in each of the sampled data trains are arranged in a random fashion. The data train formed by the addition is used, as compressed data, for communication or reproduction of signals.
A method and apparatus are disclosed for separating the information on documents involved in transactions such as accounting or banking transactions, for example, from the documents themselves and also for placing control of the processing of the transactions on this information instead of on the documents themselves. An image lift unit at a point of acceptance in a banking system disclosed herein generates an electronic image of each of the documents presented thereat and also tags the documents and the associated images with identification indicia to provide entry records which are processed at a processing center in the system to develop accounting source data and to perform accounting transactions with the accounting source data without using the documents themselves and, in turn, to produce data records which are recorded on an archival record along with the images for the associated documents. A point of payment within the system has a display unit for displaying (via the archival record) the data records and images associated with the documents for making acceptance or rejection decisions with regard to the documents and also has a printer for making copies of these documents.
A method of compressing data utilizes the prime number series to generate unique compression parameters that may be used to recover an original data stream. The original data is converted from a binary form to a decimal form. Various compression parameters are selected to initialize the system. The compression parameters include the number of prime numbers which will be used in the compression process and an exponential value corresponding to each prime number. A header is constructed which includes the compression parameters. The data is compressed by a compression algorithm which performs successive division operations by the series of prime numbers selected. The compression algorithm generates a plurality of exponential values corresponding to each of the prime numbers. The header is then assembled with the exponential values and transmitted to a receiving station. In decompressing the data, the prime numbers are raised to the exponential value generated by the compression algorithm, and their product is taken. A fault parameter may be generated to compensate for numbers not readily divisible by the prime number selected in the initialization parameters.
