AREA MAPPING TABLE LOOK UP SCHEME
Original Publication Date: 1993-Apr-30
Included in the Prior Art Database: 2004-Apr-06
Xerox Disclosure Journal
Proposed is the implementation of a look up table technique for a resolution conversion area mapping algorithm. The technique accounts for the table size and utilizes the symmetry found in the algorithm to optimize the table and reduce its size. The method is oriented toward producing an entire line as identified by an output window. All the input pixels that are necessary to produce the output scan line are identified. These pixels are then combined to form an address location in the look up table such that the addressed location contains the output values for that particular scan line. The look up table contains data for each output scan line where the size of the table is defined by a value 2X, where X is equal to the number of input pixels required to determine a corresponding output pixel. The number of the table look up entries is determined by 2N-1, where N represents the input window dimensions NxN. This design allows for an entire output tile to be created in just N steps, where N is again, by definition, the input window dimensions NXN.