1. Apparatus for compressing a pattern of digitized input data having a multiple bit width for removal of excess information and converting into a vector pattern, comprising in combination: an image matrix for storing each value of digitized input data produced by pattern scanning. a process array within said image matrix through which the digitized input data in the image matrix is shifted, means for scanning each bit of the input data in the image matrix and generating a boundary signal at a transition between a data bit of a first value and a data bit of a second value, means for tracing a boundary outlined by the stored input data during a tracing sequence in response to the boundary signal in a single bit sequence, means for changing the value of excess information bits during the tracing sequence from the first value to the second value, means responsive to each information bit of the first value after completion of the tracing sequence to generate an encoded representation of vectors having a direction based on surrounding data bits of the first and second values, and means for storing the encoded representations of the vectors in recoverable memory.