Motion Vector Estimation Using Interpolated Down-Sampled Frames

Solution Overview

Problem

Motion vector estimation in video encoding is hindered by the trade-off between high bandwidth requirements and accuracy, particularly when using down-sampled images, which can lose high-frequency details and result in inaccurate motion vectors.

Innovation Solution

A data processing apparatus that interpolates between pixels of a down-sampled reference frame to generate interpolated blocks, allowing for more accurate cost function calculations and improved motion vector estimation without increasing memory access bandwidth, by using interpolation circuitry to create a set of interpolated down-sampled reference frame blocks and selecting the block that minimizes the cost function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If down-sampled images are used for motion vector estimation, then memory access bandwidth requirements are reduced, but motion vector estimation accuracy deteriorates due to loss of high-frequency components

Engineering Contradiction:

Improvememory access bandwidthVSAvoidmotion vector estimation accuracy

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing interpolation on the down-sampled reference frame before conducting motion vector estimation. The interpolation circuitry generates interpolated down-sampled reference frame blocks by interpolating between pixels of the down-sampled reference frame, which restores high-frequency components that were lost during down-sampling. This preliminary interpolation step enables accurate motion vector estimation while still using only down-sampled frames, thus maintaining low memory bandwidth requirements while improving accuracy.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If full resolution images are used for motion vector estimation, then motion vector estimation accuracy is improved, but memory access bandwidth requirements increase

Engineering Contradiction:

Improvemotion vector estimation accuracyVSAvoidmemory access bandwidth

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by modifying the resolution parameter of the reference frame through interpolation. Instead of using full-resolution frames which require high memory bandwidth, the system takes down-sampled frames and applies interpolation to generate interpolated down-sampled reference frame blocks. This changes the effective resolution parameter locally at the positions needed for motion estimation, achieving high accuracy without the memory bandwidth cost of full-resolution frames.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If down-sampled reference frames are used, then computational complexity is reduced, but cost function calculation accuracy deteriorates

Engineering Contradiction:

Improvecomputational complexityVSAvoidcost function calculation accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing interpolation on the down-sampled reference frame before conducting motion vector estimation. The interpolation circuitry generates interpolated down-sampled reference frame blocks by interpolating between pixels of the down-sampled reference frame, which restores high-frequency components that were lost during down-sampling. This preliminary interpolation step enables accurate motion vector estimation while still using only down-sampled frames, thus maintaining low memory bandwidth requirements while improving accuracy.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9407931B2Motion vector estimator

Publication Date: 2016.08.02 ARM LTD

AI summary

A data processing apparatus is provided which is configured to receive a down-sampled source block and a down-sampled reference frame portion. The data processing apparatus comprises interpolation circuitry configured to interpolate between pixels of the down-sampled reference frame portion to generate a set of interpolated down-sampled reference frame blocks. Cost function calculation circuitry calculates a cost function value indicative of a difference between the down-sampled source block and each interpolated down-sampled reference frame block. Minimisation circuitry identifies the lowest cost function value and estimation motion vector generation circuitry generates an estimate motion vector independence thereon.