US RE50,433 E1
Computer program for generating 1-bit image data from multiple-bit image data
Andrew William Peter Cave, Cambridge (GB)
Assigned to Hamillroad Software Limited, Histon (GB)
Appl. No. 18/107,720
Filed by Hamillroad Software Limited, Histon (GB)
PCT Filed Sep. 9, 2010, PCT No. PCT/GB2010/001701
§ 371(c)(1), (2), (4) Date May 4, 2012,
PCT Pub. No. WO2011/030101, PCT Pub. Date Mar. 17, 2011.
Application 18/107,720 is a reissue of application No. 13/395,092, filed on Sep. 9, 2010, granted, now 8,654,400, issued on Feb. 18, 2014.
Claims priority of application No. 0915976 (GB), filed on Sep. 11, 2009.
Int. Cl. H04N 1/405 (2006.01); H04N 1/407 (2006.01); H04N 1/409 (2006.01)
CPC H04N 1/407 (2013.01) [H04N 1/405 (2013.01); H04N 1/409 (2013.01)] 59 Claims
OG exemplary drawing
 
[ 16. A computer system executed process for generating 1-bit image data from multiple-bit image data, the process comprising the steps of:
receiving, by the computer system, multiple-bit image data comprising multiple-bit pixel values; and
deriving, by the computer system, from the multiple-bit pixel values 1-bit image data comprising “on” and “off” pixel values, each pixel value of the 1-bit image data corresponding to a pixel of an output medium, which pixel an output device would attempt to mark when printing the 1-bit image data if the pixel value were “on”, the 1-bit image data producing when printed an image constituted by dots, each dot corresponding to a plurality of pixel values of the 1-bit image data, which pixel values correspond to a block of M*N horizontally and/or vertically adjacent pixels of the output medium, at least one of M and N being greater than one,
wherein the process further comprises converting dots to reduced-sized dots within the 1-bit image data where dot density is greater than a first threshold density, wherein converting a dot to a reduced-size dot comprises:
determining that the dot is where the dot density is greater than the first threshold density, and
setting one or more pixel values of the dot, which dot corresponds to an M*N block of horizontally and/or vertically adjacent pixels, to “off” rather than “on” within the 1-bit image data, wherein for at least some of the dots;
where M or N is equal to one, a pixel value corresponding to a first or last pixel of a row of horizontally adjacent pixels, or to a first or last pixel of a column of vertically adjacent pixels of the M*N block, is set to “off” rather than “on”, and
where both M and N are greater than one, at least one pixel value corresponding to a pixel of a first or last row of horizontally adjacent pixels of the M*N block is set to “off” rather than “on” and/or at least one pixel value corresponding to a pixel of a first or last column of vertically adjacent pixels of the M*N block is set to “off” rather than “on”. ]