Obvious "stair-stepping," or sudden shifts in tones, rather than smooth transitions in areas of tonal gradation (see left half of figure), is called Posterization. It results because of a lack of available gray levels. The number of gray levels is determined by the number of dots in a halftone cell.
If you are copying or scanning a halftoned or photographic image, and getting posterized output, try the following:
Other options include:
For more details about posterization, see About Posterization and Gray Levels.
TIP: If you have programmed and run a job, and received unexpected results, ensure that the system-wide settings are all set back to their defaults by clicking <Clear All> or <Reset> in the user interface. Then proceed to do job programming pertinent to your job. |