Patent ID: 7471422

Claim:
A computer program stored in a computer readable medium for executing on a computer system a computer process for generating a multiple-bit image data file from a 1-bit image data file, which multiple-bit file, when displayed on a display screen of the computer system, resembles an image that would appear on an output medium as a result of printing of the 1-bit file by an output device, the computer process comprising: receiving a 1-bit image data file comprising an array of “on” and “off” pixels, each pixel corresponding to a notional rectangular region of an output medium, which notional rectangular region an output device would attempt to mark when printing the 1-bit file if the pixel were an “on” pixel; receiving at least one first value that characterises a size and a shape of an actual region of the output medium that would be marked by the output device when printing a single “on” pixel of the 1-bit file; receiving at least one second value that characterises a size and a shape of an actual region of the output medium that would be marked by the output device when printing two or more consecutive “on” pixels of the 1-bit file; and for each pixel in turn of the 1-bit file: determining which of that pixel and the pixels neighbouring that pixel are “on” pixels; calculating from the pixels determined to be “on” pixels and the first and second values, a proportion of the notional rectangular region of the output medium to which that pixel corresponds that would be marked by the output device when printing the pixels determined to be “on” pixels; and setting a value of a pixel of a multiple-bit image data file corresponding to that pixel according to the calculated proportion of the notional rectangular region of the output medium.