System for Replacing a Portion of an Image Data Stream in an Ink Jet Printer

A system detects image data in an image data stream that cause ink ejection errors and replaces the image data with a replacement pattern that attenuates the ink ejection errors. The system includes a scanline memory for storing image data, an input data register for forming an image data pattern from image data read from the scanline memory and an image bit received from an image data stream, an image data pattern detection circuit having a comparator that is configured to compare a portion of an image data bit stream used to drive a print head in an ink jet printer to a plurality of detection bit patterns and to generate a bit pattern detection signal in response to the portion of the image data bit pattern corresponding to one of the detection bit patterns, a replacement bit pattern circuit being configured to replace the portion of the image data bit stream corresponding to one of the detection bit patterns with a replacement bit pattern, the replacement bit pattern being different than the detected bit pattern, a tag register coupled to the image data pattern detection circuit and being configured to modify the comparison of the portion of the image data bit stream to one of the detection bit patterns, and an output data register for providing a replacement image bit from the replacement bit pattern to a print head controller and for storing a remainder of the replacement bit pattern to the scanline memory.