Method of tone reproduction with halftone dots, apparatus for outputting halftone plate, halftone plate, and printed material

摘要

Tone jumps are eliminated in all areas ranging from a highlight area through an intermediate tone area to a shadow area for thereby achieving a smoother tone reproduction. Halftone dots are grown in a circular shape from a halftone percentage of 0% to a first highlight percentage. Halftone dots are grown while changing from the circular shape to a square shape from the first highlight percentage to a second highlight percentage greater than the first highlight percentage. Halftone dots are grown in a square shape from the second highlight percentage to a second shadow percentage. Halftone dots are grown while changing from the square shape to a circular shape from the second shadow percentage to a first shadow percentage greater than the second shadow percentage. Halftone dots are grown in a circular shape from the first shadow percentage to a percentage of 100%. The dots stick well to the print sheet in the highlight area and clearly define inter-dot spaces in the shadow area, and no tone jumps occur in the vicinity of the halftone percentages of 50% and 78.5%.