Patent ID: 8175168

Claim:
A method for direct picture up-sampling from a lower resolution picture to a higher resolution picture, said method comprising: a) for each spatial offset in a plurality of spatial offsets, storing a set of filter coefficients associated with said each spatial offset; b) in a video processor, wherein said video processor is a processor selected from the group consisting of a video encoder and a video decoder, for a sample position in said higher resolution picture, wherein said sample position is not associated with twice the resolution of said lower resolution picture, deriving a corresponding location in said lower resolution picture; c) in said video processor, calculating a first position interpolation center in a first direction based on said corresponding location; d) in said video processor, calculating a first position phase, wherein said first position phase is an offset of said corresponding location from said first position interpolation center in said first direction; e) in said video processor, calculating a second position interpolation center in a second direction based on said corresponding location; f) in said video processor, calculating a second position phase, wherein said second position phase is an offset of said corresponding location from said second position interpolation center in said second direction; g) in said video processor, obtaining a first set of filter coefficients from said plurality of stored sets of filter coefficients, wherein said obtaining said first set of filter coefficients comprises obtaining said stored set of filter coefficients associated with said first position phase; h) in said video processor, obtaining a second set of filter coefficients from said plurality of stored sets of filter coefficients, wherein said obtaining said second set of filter coefficients comprises obtaining said stored set of filter coefficients associated with said second position phase; i) in said video processor, filtering said lower resolution picture in said first direction at said first interpolation center using a first filter comprising said first set of filter coefficients, thereby producing a first filtered picture value at said first position phase relative to said first interpolation center; j) in said video processor, filtering a first-direction filtered picture comprising said first filtered picture value at said first position phase relative to said first interpolation center in said second direction at said second interpolation center using a second filter comprising said second set of filter coefficients, thereby directly producing a pixel value at said sample position in said higher resolution picture without formation of an intermediate resolution picture; and k) wherein the spatial resolution of said higher resolution picture is greater than twice the spatial resolution of said lower resolution picture.