método para a compressão e deslocamento em uma direção de varredura e impressão de página e processo para imprimir um livreto

Shifting a page image while it is still in compressed form. The page image is compressed into independent strips that are a full page in the fast scan direction, and a small number of scanlines in the slow scan direction. Then, to shift the page image, whole strips can be deleted in one margin and/or deleted from the other. If the number of scanlines per strip is small enough, the difference in a margin created by the change of one strip will not be apparent. This invention can be used to advantage when it is decided at print time that the output shall be in the form of a saddle-stitched booklet requiring two-up printing, folding and subsequent trimming of the outside edges to uniform alignment. Here, a progressive page shift can be introduced at the printer controller while the images are still compressed, instead of requiring the change to be done to the PostScript Master, which would require reRIPing or decompression, shift and recompression.