Resampling and picture resizing operations for multi-resolution video coding and decoding
First Claim
1. A method of resampling for multi-resolution video coding or decoding using a computing device that implements a video encoder or decoder, the computing device including a processing unit and memory, the method comprising:
- with the computing device that implements the video encoder or decoder, performing resampling of image data according to a horizontal resampling scale factor, wherein the resampling comprises computation of a sample value at horizontal position i in a resampled array, and wherein the computation comprises;
computing a derived horizontal sub-sample position x in a manner that is mathematically equivalent in result to the formula x=(i*C+D)>
>
S, wherein C is derived by approximating a value equivalent to 2S+F multiplied by an inverse of the horizontal resampling scale factor, and wherein F, C, D, and S are integer values.
2 Assignments
0 Petitions
Accused Products
Abstract
Techniques and tools for high accuracy position calculation for picture resizing in applications such as spatially-scalable video coding and decoding are described. In one aspect, resampling of a video picture is performed according to a resampling scale factor. The resampling comprises computation of a sample value at a position i,j in a resampled array. The computation includes computing a derived horizontal or vertical sub-sample position x or y in a manner that involves approximating a value in part by multiplying a 2n value by an inverse (approximate or exact) of the upsampling scale factor. The approximating can be a rounding or some other kind of approximating, such as a ceiling or floor function that approximates to a nearby integer. The sample value is interpolated using a filter.
-
Citations
22 Claims
-
1. A method of resampling for multi-resolution video coding or decoding using a computing device that implements a video encoder or decoder, the computing device including a processing unit and memory, the method comprising:
with the computing device that implements the video encoder or decoder, performing resampling of image data according to a horizontal resampling scale factor, wherein the resampling comprises computation of a sample value at horizontal position i in a resampled array, and wherein the computation comprises; computing a derived horizontal sub-sample position x in a manner that is mathematically equivalent in result to the formula x=(i*C+D)>
>
S, wherein C is derived by approximating a value equivalent to 2S+F multiplied by an inverse of the horizontal resampling scale factor, and wherein F, C, D, and S are integer values.
-
2. A method of resampling for multi-resolution video coding or decoding using a computing device that implements a video encoder or decoder, the computing device including a processing unit and memory, the method comprising;
with the computing device that implements the video encoder or decoder, performing resampling of image data according to a vertical resampling scale factor, wherein the resampling comprises computation of a sample value at vertical position j in a resampled array, and wherein the computation comprises; computing a derived vertical sub-sample position y in a manner that is mathematically equivalent in result to the formula y=(j*C+D)>
>
S, wherein C is derived by approximating a value equivalent to 2S+F multiplied by an inverse of the vertical resampling scale factor, and wherein F, C, D, and S are integer values.
-
3. A method of upsampling for multi-resolution video coding or decoding using a computing device that implements a video encoder or decoder, the computing device including a processing unit and memory, the method comprising:
with the computing device that implements the video encoder or decoder, performing upsampling of a video picture according to a horizontal upsampling scale factor and a vertical upsampling scale factor, wherein the upsampling comprises computation of an interpolated sample value at horizontal position i and vertical position j in an upsampled array, and wherein the computation comprises; computing a derived horizontal sub-sample position x in a manner that is mathematically equivalent in result to the formula x=(i*C+D)>
>
S, wherein C is derived by approximating a value equivalent to 2S+F multiplied by an inverse of the horizontal upsampling scale factor, and wherein F, C, D, and S are integer values;computing a derived vertical sub-sample position y in a manner that is mathematically equivalent in result to the formula y=(j*C+D)>
>
S, wherein C is derived by approximating a value equivalent to 2S+F multiplied by an inverse of the vertical upsampling scale factor; andinterpolating a sample value at the derived sub-sample position x, y. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
22. A method of upsampling for multi-resolution video coding or decoding using a computing device that implements a video encoder or decoder, the computing device including a processing unit and memory, the method comprising:
with the computing device that implements the video encoder or decoder, performing upsampling of a video picture according to an upsampling scale factor, wherein the upsampling comprises computation of an interpolated sample value at horizontal position i and vertical position j in an upsampled array, and wherein the computation comprises; computing a derived horizontal sub-sample position x in a manner mathematically equivalent in result to the formula x=((2J*i+Q)*C+D)>
>
S, wherein C is derived by approximating a value equivalent to 2S+F multiplied by an inverse of the upsampling scale factor, and wherein F, C, D, S, J and Q are integers;computing a derived vertical sub-sample position y in a manner that is mathematically equivalent in result to the formula y=((2J*j+Q)*C+D)>
>
S; andinterpolating a sample value at the derived sub-sample position x, y.
Specification