Color table level reservation

摘要

The present invention addresses problems encountered in the conversion of continuous tone data into binary data for printing on low resolution imaging systems. Representation of the continuous tone data is only roughly approximated through the conversion to binary data. Artifacts of the binary printing process are objectionable for several reasons. They decrease over all image quality and may sometimes allow for only partial representation of the original data. Partially formed and/or irregularly formed text characters are one such example. This invention addresses this problem by forcing certain levels to be processed through predictable dot dispersion patterns so as to preserve pre-identified portions of the input data stream. Continuous tone image data for imaging on a digital output device is processed by identifying at least one problematic tone level in the binary representation of the image, and identifying at least one non-problematic tone level in the binary representation of the image. Data transformation is then applied to cause the digital output device to replace the at least one problematic tone level in the binary representation of the image with output at the at least one non-problematic tone level in the binary representation of the image. <IMAGE>