Picture element interpolation method

Abstract

An interpolating method of pixel includes filtering pixel sample by five-tap filter to obtain intermediate value, normalizing intermediate value and clamping normalized value in range of [ 0, 255 ] for obtaining prediction value of pixel interpolation.

Description

technical field

[0001] The invention relates to video image encoding and decoding technology, in particular to a pixel interpolation method. Background technique

[0002] At present, in some video standards, 1 / 2 pixel interpolation and 1 / 4 pixel interpolation are generally used in order to obtain a higher-precision prediction value, reduce the size of the motion compensation residual, and reduce the bit rate. However, interpolation, especially 1 / 4 pixel interpolation, is computationally intensive and time-consuming, and is an important factor affecting the execution speed and efficiency of codec programs. In the traditional video standard, 1 / 4 pixel interpolation is achieved in two steps, that is, first obtain 1 / 2 pixel interpolation through a multi-tap filter, and then filter 1 / 2 pixel interpolation through another multi-tap filter to obtain 1 / 2 4 pixel predicted value. In this pixel interpolation method, a 1 / 4 pixel interpolation not only requires two multi-tap filters t...

Examples

Embodiment

[0037] figure 1 A schematic diagram of pixel interpolation of this example is shown.

[0038] 1. The 1 / 4 sample marked aa in the figure is obtained by:

[0039] ① First, use the five-tap filter F3 to filter the five integer pixel samples A, B, C, D, and E in the horizontal direction closest to the current interpolation sample, and obtain the intermediate value aa', as follows:

[0040] aa'=(-A-2B+96C+42D-7E)

[0041] ② The final predicted value aa can be obtained according to the following formula:

[0042] aa=Clipl((aa'+64)>>7)

[0043] 2. The 3 / 4 sample marked bb in the figure is obtained by:

[0044] ① First, use the five-tap filter F4 to filter the five integer pixel samples A, B, C, D, and E in the horizontal direction closest to the current interpolation sample to obtain the intermediate value bb', as follows:

[0045] bb'=(-7A+42B+96C-2D-E)

[0046] ② The final predicted value bb is calculated according to the following formula:

[0047] bb=Clipl((bb'+64)>>7)

...

technical field

[0001] The invention relates to video image encoding and decoding technology, in particular to a pixel interpolation method. Background technique

[0002] At present, in some video standards, 1 / 2 pixel interpolation and 1 / 4 pixel interpolation are generally used in order to obtain a higher-precision prediction value, reduce the size of the motion compensation residual, and reduce the bit rate. However, interpolation, especially 1 / 4 pixel interpolation, is computationally intensive and time-consuming, and is an important factor affecting the execution speed and efficiency of codec programs. In the traditional video standard, 1 / 4 pixel interpolation is achieved in two steps, that is, first obtain 1 / 2 pixel interpolation through a multi-tap filter, and then filter 1 / 2 pixel interpolation through another multi-tap filter to obtain 1 / 2 4 pixel predicted value. In this pixel interpolation method, a 1 / 4 pixel interpolation not only requires two multi-tap filters t...

Examples

Embodiment

[0037] figure 1 A schematic diagram of pixel interpolation of this example is shown.

[0038] 1. The 1 / 4 sample marked aa in the figure is obtained by:

[0039] ① First, use the five-tap filter F3 to filter the five integer pixel samples A, B, C, D, and E in the horizontal direction closest to the current interpolation sample, and obtain the intermediate value aa', as follows:

[0040] aa'=(-A-2B+96C+42D-7E)

[0041] ② The final predicted value aa can be obtained according to the following formula:

[0042] aa=Clipl((aa'+64)>>7)

[0043] 2. The 3 / 4 sample marked bb in the figure is obtained by:

[0044] ① First, use the five-tap filter F4 to filter the five integer pixel samples A, B, C, D, and E in the horizontal direction closest to the current interpolation sample to obtain the intermediate value bb', as follows:

[0045] bb'=(-7A+42B+96C-2D-E)

[0046] ② The final predicted value bb is calculated according to the following formula:

[0047] bb=Clipl((bb'+64)>>7)

...

Images