Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
234 words
A method of compressing data comprising the steps of dividing each picture frame into a predetermined number of macroblocks, selecting a candidate macroblock from each of the similar macroblocks in a previous frame, and encoding a motion vector and a difference between a current macroblock and said candidate macroblock, said method further including a motion estimating method, which comprises the steps of: (a) obtaining a motion vector (x o , y o ) which minimizes a predetermined error function; (b) assuming a preferred motion vector (x, y); (c) calculating a difference (x-diff, y-diff) between (x o , y o ) and (x, y); (d) obtaining a bit number corresponding to a number of bits needed to encode said x-diff and y-diff; (e) determining a bias based on a bias model according to said bit number; (f) obtaining a final cost function value by means of the difference between a cost function value and a bias; (g) comparing said final cost function value with a predetermined allowance limit; (h) setting said assumed motion vector (x, y) as a motion vector for a current macroblock and updating said allowance limit by using said cost function value, if said cost function value is smaller than said limit value in said step (g); and (i) discarding said assumed motion vector (x, y) if said cost function value is not smaller than said limit value in said step (g).
Claim 2
Independent Claim
234 words
A method of compressing data comprising the steps of dividing each picture frame into a predetermined number of macroblocks, selecting a candidate macroblock from each of the similar macroblocks in a previous frame, and encoding a motion vector and a difference between a current macroblock and said candidate macroblock, said method further including a motion estimating method, which comprises the steps of: (a) obtaining a motion vector (x o , y o ) which minimizes a predetermined error function; (b) assuming a preferred motion vector (x, y); (c) calculating a difference (x-diff, y-diff) between (x o , y o ) and (x, y); (d) obtaining a bit number corresponding to a number of bits needed to encode said x-diff and y-diff; (e) determining a bias based on a bias model according to said bit number; (f) obtaining a final cost function value by means of the difference between a cost function value and a bias; (g) comparing said final cost function value with a predetermined allowance limit; (h) setting said assumed motion vector (x, y) as a motion vector for a current macroblock and updating said allowance limit by using said cost function value, if said cost function value is smaller than said limit value in said step (g); and (i) discarding said assumed motion vector (x, y) if said cost function value is not smaller than said limit value in said step (g).
Claim 3
Dependent Claim
33 words
The method as defined in claim 1, wherein said step (b) comprises the step of selecting one of the motion vectors of a previous block, an upper block, and an upper right block.
Claim 4
Dependent Claim
43 words
The method as defined in claim 1, wherein said error function is a sum of the absolute difference (SAD) determined by the following equation: ##EQU3## where f and f i are sizes of signals in a current frame and a previous frame, respectively.
Claim 5
Dependent Claim
59 words
The method as defined in claim 1, wherein said error function is a mean absolute error (MAE) determined by the following equation: ##EQU4## where f and f i are the sizes of signals in a current frame and a previous frame, respectively, and M and N are the numbers of horizontally and vertically arranged pixels in each block, respectively.
Claim 6
Dependent Claim
13 words
The method as defined in claim 1, wherein said bias model is linear.
Claim 7
Dependent Claim
15 words
The method as defined in claim 1, wherein said bias model is a Gaussian function.
Claim 8
Dependent Claim
18 words
The method as defined in claim 1, wherein said bias model is the square of a Gaussian function.