| US 7,580,564 B2 | ||
| Method of an image processor for transforming a n-bit data packet to a m-bit data packet using a lookup table | ||
| James Ray Bailey, Shelbyville, Ky. (US); Curt Paul Breswick, Georgetown, Ky. (US); David Allen Crutchfield, Georgetown, Ky. (US); Thomas Jon Eade, Lexington, Ky. (US); and Zachary Nathan Fister, Lexington, Ky. (US) | ||
| Assigned to Lexmark International, Inc., Lexington, Ky. (US) | ||
| Filed on May 13, 2004, as Appl. No. 10/844,787. | ||
| Prior Publication US 2005/0254706 A1, Nov. 17, 2005 | ||
| Int. Cl. G06K 9/00 (2006.01); G06K 9/36 (2006.01) | ||
| U.S. Cl. 382—166 [382/251] | 19 Claims |
| 1. A method of transforming a n-bit data packet to a m-bit data packet with a lookup table, the lookup table comprising at
least one entry data packet and at least one respective delta value associated with each entry data packet, the method comprising
the acts of:
receiving an input data packet comprising n-bits,
indexing the lookup table with at least a portion of the input data packet to obtain one of the at least one entry data packet;
and
decompressing the obtained entry data packet with the at least one respective delta value associated with the obtained entry
data packet, the decompressing act comprising using a portion of the input data packet to determine the number of delta values
needed for decompressing the obtained entry data packet, the decompressing act resulting in an output data packet comprising
m-bits,
wherein the input data packet is represented by input value (n−1:0), wherein the indexing act comprises the act of indexing
the lookup table with the bits input value (n−1:q) to obtain one of the at least one entry data packet, and wherein the using
act comprises using the bits input value (q−1:0) to determine the number of delta values called for decompressing the obtained
entry data packet,
wherein the number of entry data packets of the lookup table is represented by z, and wherein q is represented by q=n−k, where
k is represented by k=ceiling(log2(z)), and
wherein the number of respective delta values associated with each entry data packet of the lookup table is represented by
c where c is represented by c=(2n)/z−1.
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