公开(公告)号：EP1401190B1

公开(公告)日：2013-05-29

申请号：EP03103372.3

申请日：2003-09-12

Applicant: Agfa Graphics N.V.

Inventor： Minnebo, Luc ,  Vande Velde, Koen ,  Delabastita, Paul

IPC: H04N1/405 ,  B41C1/10

CPC classification number: H04N1/4052

公开(公告)号：EP1406433A3

公开(公告)日：2007-05-23

申请号：EP03103376.4

申请日：2003-09-12

Applicant: Agfa Graphics N.V.

Inventor： Minnebo, Luc ,  Vande Velde, Koen ,  Delabastita, Paul

IPC: H04N1/405 ,  H04N1/52

CPC classification number: H04N1/52 ,  H04N1/4052

Abstract: Printing masters are produced by use of an inkjet printing system.
The smallest halftone dot size which can be printed by the inkjet printing system is larger than the size of a pixel of the recording grid defined by the addressability of the printing device.
Inferior image quality and graininess caused by standard error diffusion algorithms in this system can be counteracted by using a constraint correlation error diffusion system.
Out of the complete set of all possible intensity level combinations for reproducing a pixel a subset is selected based upon the multilevel halftoning process of a quantized scalar value which is a function of at least one of the input pixel values of the corresponding colour component pixels.
Preferably the scalar value represents the brightness or ink amount allocations.