Pixel Compression Predictor Selection for Faster Lossless Encoding

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Solution Overview

Problem

Existing data compression techniques for pixel information face challenges in achieving optimal compression ratios and efficiency, particularly in balancing compute resources, power consumption, and accuracy between lossless and lossy compression methods.

Innovation Solution

The approach involves determining the most suitable lossless or lossy compression technique for a given block of pixels by evaluating multiple predictors in parallel, selecting the technique that provides the smallest compression size, and dynamically adjusting bit widths and using bias to optimize compression ratios, while falling back to lossy compression if lossless techniques cannot meet a target output size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If lossless compression techniques are used to preserve data accuracy, then data fidelity is improved, but compression ratio and processing speed deteriorate

Engineering Contradiction:
Improvedata fidelityVSAvoidcompression speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent implements dynamic selection among multiple compression techniques (e.g., PNG, JPEG, WebP) based on real-time evaluation of compression ratios and processing speeds. The system adapts the compression approach for different image blocks or regions, switching between lossless and lossy methods to optimize both fidelity and speed according to specific data characteristics.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system varies compression parameters such as quality thresholds, bit depths, and algorithmic settings to balance fidelity and speed. By adjusting these parameters dynamically based on image content analysis, the system achieves optimal compression performance without sacrificing necessary data accuracy.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If multiple compression techniques are evaluated in parallel to select the optimal method, then compression ratio is improved, but compute resources and device complexity increase

Engineering Contradiction:
Improvecompression ratioVSAvoidcompute resources
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the compression evaluation process into segments where different techniques are applied to different image regions or blocks. Instead of evaluating all techniques on the entire image, the system segments the work to reduce per-evaluation compute resources while maintaining overall optimization through selective application of the best-performing techniques.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs partial evaluation of compression techniques by assessing only critical metrics (such as initial compression ratio estimates) rather than full decompression and reconstruction validation. This partial action approach reduces compute resources required for technique selection while still identifying optimal compression methods efficiently.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If lossy compression is used to achieve smaller file sizes, then compression ratio is improved, but data accuracy deteriorates

Engineering Contradiction:
Improvecompression ratioVSAvoiddata accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies different compression methods to different regions of the image based on local quality requirements. Critical regions (such as edges, text, or important features) are compressed using lossless or high-fidelity lossy techniques, while less critical regions use more aggressive lossy compression. This local differentiation maintains data accuracy where needed while achieving better overall compression ratios.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system incorporates feedback mechanisms that evaluate the quality impact of lossy compression in real-time. By monitoring distortion metrics and comparing against threshold values, the system adjusts compression aggressiveness dynamically, ensuring data accuracy is maintained within acceptable boundaries while maximizing compression ratios.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11843788B2Lossless compression techniques
Publication Date: 2023.12.12 APPLE INC
  • US11843788B2 patent drawing
  • US11843788B2 patent drawing
  • US11843788B2 patent drawing

AI summary

Techniques are disclosed relating to data compression. In some embodiments, compression circuitry determines, at least partially in parallel for multiple different lossless compression techniques, amounts of data needed to represent, using a given lossless compression technique of the multiple lossless compression techniques, individual pixels in a set of pixels being compressed. The compression techniques may include neighbor, origin, and gradient techniques, for example. The compression circuitry may select one of the compression techniques based on comparison, among the compression techniques, of sums of: the determined amount of data for an individual pixel for a given lossless compression technique and compression metadata size for a given lossless compression technique. The compression circuitry may generate and store information that encodes values for the set of pixels using the selected compression technique.