The present invention provides a process for compensating for error in the position of characters in a character string that can result from printing text data intended for a printer having one resolution on a printer having equivalent fonts, but a different resolution. The method comprises the steps of determining the conversion error for a character in a string of characters, accumulating the conversion error, determining whether the accumulated conversion error equals or exceeds a predetermined threshold value, positioning the next character in the string from the present character by the amount of the predetermined threshold value and decrementing the accumulated conversion error, provided the accumulated conversion error equaled or exceeded the predetermined threshold value, and repeating the above steps for the next character in the character string. The invention further includes the additional steps of examining character strings occupying the same baseline for instances in which a relative move of one character string abuts a relative move or a space character of another character string, and in such instances replacing the relative move and the abutting relative move or space with an equivalent relative move.

An apparatus for retrieving or searching character strings which can be fabricated with a simplified structure and operate at a high speed. A memory circuit storing a standard character string is employed. The memory circuit includes a plurality of input lines each corresponding to one of the characters in the standard character string, a plurality of output lines and memory cells. Each of output lines of the memory circuit is used to enable transfer operation of one stage of a sequential logic circuit, and a detection output is derived from the sequential logic circuit when all the stages are enabled in a predetermined order.

A character compressing method is disclosed wherein a character is separately grouped at a predetermined pitch in the horizontal direction (row direction) or vertical direction (column direction), and a dot start position and continuous dot length are used as a data for each section having a print dot. In a character modifying method using a character data stored in the manner following the character compressing method, the dot start position data and continuous dot length data are derived as fundamental parameters, the data is subjected to a character modifying operation corresponding to one of various modifying modes, and in accordance with the operation results, the dot start address is changed and print dot information corresponding in amount to the continuous dot length is given.

A method and apparatus for manipulating run-length encoded rasterized images. Sizing, slanting, rotating or otherwise transforming an image outline to a new orientation is accomplished without converting image information into a bit map or discrete pixel format. An image outline is characterized in terms of visible and invisible vectors along an input raster scan line by relating run-lengths in a previous input scan line with run-lengths in a current input scan line. The resulting vector characterization allows determination of crossover points on output raster scan lines for the manipulated image by means of transform coefficients. Memory bins store these crossover points, and these bins are sorted to construct a new run-length encoded image outline.

Digital encoding and decoding apparatus for encoding data codes to produce disk codes and decoding disk codes to produce data codes. In the encoding and decoding operations performed by the apparatus, the output consists of a code and a state which are produced from a current input code, a next input code, and the state code produced by the last operation. The apparatus consists of a PROM and a state code register for retaining the state code produced by the last encoding or decoding operation. The registers in the prom contain two sets of code-status words. Each code-status word in one set contains a disk code and a state code which are the result of an encoding operation; each code-status word in the other set represents a data code and a state code which are the result of a decoding operation. The state code register receives the bits of the code-status word which contain the state code. In an encoding operation, the address inputs for the PROM consist of the state code retained in the state register, a signal indicating that an encoding operation is taking place, and the current and next data codes to be encoded. The register thus addressed by these inputs contains a code status word representing the result of the encoding operation. The decoding operation works similarly, except that the address inputs are the state code, bits of the current and next disk codes to be decoded, and a signal indicating that a decoding operation is taking place.