Patent ID: 7061487

Claim:
A method for improving bandwidth for depth information communication in a computer graphics system, comprising the steps of: obtaining a set of plane parameters for a new polygon if a collection of pixels is modified by the new polygon and indicating which pixel in the collection of pixels is modified; determining if prior depth information with respect to the collection of pixels has been encoded previously; if the prior depth information is encoded, then performing the steps of: retrieving a plane pattern and a parameter record for the prior depth information with respect to the collection of pixels from a storage area; assigning a new plane number to a location in the plane pattern, in which the assigned location corresponds to the modified pixel in the collection of pixels; appending the set of plane parameters for the new polygon to the parameter record associated with the plane pattern, wherein the set of plane parameters for the new polygon comprises an initial depth value of the new polygon for the collection of pixels, and a first and second depth slope value of the new polygon in which the first depth slope value is in respect of a first direction and the second depth slope value is in respect of a second direction; determining if new depth information with respect to the collection of pixels modified by the new polygon is worth encoding; if the new depth information with respect to the collection of pixels is worth encoding, then performing the steps of: storing the plane pattern and the parameter records that are updated to encode the new depth information back to the storage area; updating a type table associated with the collection of pixels to indicate a total number of effective plane parameter sets stored in the parameter record; deleting a redundant set of plane parameters from the parameter record associated with the plane pattern if the new polygon completely covers a prior polygon represented by the redundant set of plane parameters within the collection of pixels; and re-numbering the effective plane sets in the parameter record associated with the plane pattern including the set of plane parameters for the new polygon, wherein the determining step of encoding comprises: evaluating the total number of the effective plane parameter sets stored in the parameter record associated with the plane pattern; and determining that the new depth information need not be encoded if the total number of the effective plane parameter sets is beyond a predetermined number.