International Business Machines Corporation

Karen K Kellam

Ronnie Chi-on Tong

Phuc Ky Do

Carol E Wyke

Ronald W Willis

This invention relates to a method for generating character images using a font compression algorithm that reduces the storage requirements associated with low-cost, high resolution printers. An expanded character image has original print slices and duplicate print slices identical to one or more of the original print slices where the duplicate print slices are eliminated in the compressed character image. The compressed character is expanded using a repetition mask that identifies the number and location of the duplicate print slices. The technique for expanding the compressed character is such that printing can be performed in real time, in either a forward or reverse direction with only minimal effects on processing. This invention also provides a means for supporting multiple pitches, such as 10 CPI, 12 CPI and Proportional Space Mode (PSM), within those storage constraints. The technique of this invention is efficient enoughh to be performed by microcode in real time, yet provides for significant reduction in the overall memory required for storing the font data.

Method and apparatus for generating a character image

A method for converting original print data of one resolution N into print data of a higher resolution M. The small segment N1 original data is determined by comparing N to M and deriving the smallest fraction therefrom. Additional data is added to the original data by inserting M1-N1 blank data commands evenly between each of the original data. Each inserted blank is converted to a print command when the preceding and following original data are print commands.

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China Grove, NC, United States of America

Karen K Kellam