摘要 |
<p>A method is disclosed for producing a colour image by printing on a sheet a plurality of monochrome images on top of each other. The monochrome image (37) is composed of microdots (36), having an address (x,y). Each microdot (36) is represented by a pixel (32). The pixel (32) carries information about the address (x,y) and an image signal Ix,y that corresponds with the density to be printed on the microdot (36). This image signal is given as 8 bit signal data for example. The microdots (36) are partitioned by a screen (40) in identical screen cells (33), composed of M microdots (36). Each microdot is associated with a pixeltonecurve (34). The image signal Ix,y is transformed to a bitmap signal B by the pixeltonecurve (34) corresponding to the microdot (36). The bitmap signal B is represented by 2 or 4 bit resulting in important memory savings for the bitmap signals. The bitmap signal B is further transformed to a printer signal. The printer signal is transformed by printing to a density on the microdot (36) with address (x,y).</p> |