Abstract: A method and circuit for processing image data of a dot matrix printer in a page printer. Dot matrix image data is received and how many dots in the page printer correspond to one dot of the image data is calculated. A bit number representative of the location in vertical pins of a dot matrix printer head is initialized to a most significant pin number. A bit corresponding to the bit number of the input data is checked to form a line segment and the line segment is converted into raster data. Further, the raster data inserted in an image buffer, and data of the image buffer is stored in a symbolic buffer. A check is made to see if the bit number of the input data is a least significant pin number. If the bit number of the input data is not the least significant pin number, a next pin number is redesignated.

Abstract: In a graphic processing method in a dot matrix printer, a previous graphic mode and a previous position value of an image data are respectively compared with a current graphic mode and a current position value of an image data. If the previous and current graphic modes and position values are identical to each other, an overwrite flag is set to on, and if the previous and current position values are not identical to each other and a value obtained by subtracting the previous position value from the current position value is within a space fill-in region, space fill-in process is performed. Thereafter, the current position value is replaced to the previous position value when the value is not within the space fill-in region or the space fill-in process is ended, and a pin number is initialized. Then an image data with respect to a corresponding pin is generated, and whether or not the overwrite flag is set to on is checked.