Appeal No. 1998-2676
Application 08/655,423
the examiner to contain allowable subject matter.
The disclosed invention pertains to a method and
apparatus for reducing the number of levels in a multi-level
grey scale pixel value representing a pixel and diffusing an
error generated from reducing the number of levels. The
invention adjusts the tonal reproduction curve of a printing
system so as to compensate for spot overlap produced by a
printing device.
Representative claim 1 is reproduced as follows:
1. A method of reducing a number of grey levels of a
multi-level grey scale pixel value representing a pixel and
diffusing an error generated from reducing the number of grey
levels, comprising the steps of:
(a) receiving a multi-level grey scale pixel value, the
multi-level grey scale pixel value having a first spatial
resolution;
(b) generating a screened multi-level grey scale pixel
value from the received multi-level grey scale pixel value;
(c) reducing the number of grey levels in the screened
multi-level grey scale pixel value;
(d) generating an error value as a result of the
reduction process in step (c);
(e) modifying the generated error value based on an
effective spot area value to generate a modified error value,
the effective spot area value being dependent on the multi-
level grey scale pixel value; and
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