Luminance-Based Texture Compression for Handheld Devices

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Solution Overview

Problem

Existing texture compression schemes, such as S3TC, require sophisticated processing for selecting representative colors and computing indices, which can be complex and costly in terms of processing power and area, especially for handheld devices.

Innovation Solution

A simpler compression scheme that computes luminance values for each texel, selects representative colors based on minimum and maximum luminance, and maps these values to indices for interpolation, reducing computational complexity and power consumption while maintaining acceptable image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If S3TC compression scheme is used to achieve effective data compression and maintain image quality, then compression ratio is improved, but processing complexity increases

Engineering Contradiction:
Improvedata compression ratioVSAvoidprocessing complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent transforms the color selection problem from RGB color space to luminance space. Instead of computing representative colors in three-dimensional RGB space using eigenvalue decomposition, the method computes luminance values (a one-dimensional parameter) for each texel and selects representative colors based on minimum and maximum luminance values. This parameter transformation simplifies the compression algorithm while maintaining image quality.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If S3TC compression scheme is used to achieve effective data compression, then compression ratio is improved, but power consumption increases

Engineering Contradiction:
Improvedata compression ratioVSAvoidpower consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent reduces computational complexity by changing from three-dimensional RGB color space operations to one-dimensional luminance value computations. Luminance values require only simple arithmetic operations (weighted sum of R, G, B components) compared to the eigenvalue decomposition required by S3TC, significantly reducing power consumption for handheld devices.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If S3TC compression scheme is used to achieve effective data compression, then compression ratio is improved, but processing area increases

Engineering Contradiction:
Improvedata compression ratioVSAvoidprocessing area
Core Design Contradiction:
Quantity of substanceVSArea of moving object

Solution Approach 1:

The patent replaces complex matrix operations (eigenvalue decomposition of 16×16 inertia tensor) with simple luminance value computations and comparisons. This parameter transformation enables implementation with smaller processing units and less silicon area, making the compression scheme suitable for resource-constrained handheld devices.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS8594441B1Compressing image-based data using luminance
Publication Date: 2013.11.26 NVIDIA CORP
  • US8594441B1 patent drawing
  • US8594441B1 patent drawing
  • US8594441B1 patent drawing

AI summary

Image-based data, such as a block of texel data, is accessed. The data includes sets of color component values. A luminance value is computed for each set of color components values, generating a range of luminance values. A first set and a second set of color component values that correspond to the minimum and maximum luminance values are selected from the sets of color component values. A third set of color component values can be mapped to an index that identifies how the color component values of the third set can be decoded using the color component values of the first and second sets. The index value is selected by determining where the luminance value for the third set lies in the range of luminance values.