HDR Image Encoding via Luminance Chrominance Segmentation

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Solution Overview

Problem

Current image and video compression algorithms, such as JPEG and MPEG, struggle with efficiently encoding and decoding high dynamic range (HDR) and high bit-depth images, leading to visible artifacts and high computational power requirements, especially in high-definition resolutions.

Innovation Solution

The proposed solution involves separating HDR images into chrominance and luminance components, using pixel shaders to reconstruct the original texture, and applying error correction techniques to minimize data loss, allowing for efficient compression and decoding compatible with existing standards like JPEG and MPEG.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If HDR images are encoded using standard compression algorithms (JPEG, MPEG), then compression ratio is improved, but image quality deteriorates due to visible artifacts

Engineering Contradiction:
Improvedata compression ratioVSAvoidimage quality
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent segments HDR image data into multiple components: base layer (clamped LDR version), enhancement layers (fractional color information at different bit depths), and exponent data. This segmentation allows each component to be processed and compressed separately, preserving critical HDR information while enabling efficient compression. The base layer provides fallback compatibility while enhancement layers recover fine details, thus maintaining image quality during compression.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transforms HDR image representation by separating mantissa (fractional color) and exponent components, and by converting between different bit depth representations (16-bit, 32-bit, 64-bit floating point). This parameter transformation enables the use of standard compression algorithms on transformed data while preserving the ability to reconstruct high-quality HDR images through inverse transformation.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If HDR images are encoded with high precision, then image quality is improved, but computational power requirements increase

Engineering Contradiction:
Improveimage precisionVSAvoidcomputational power
Core Design Contradiction:
Manufacturing precisionVSPower

Solution Approach 1:

The patent implements progressive precision encoding where a base layer provides acceptable quality at lower computational cost, and enhancement layers add incremental precision. This allows systems to operate at partial precision (base layer only) when computational resources are limited, while enabling full precision (all enhancement layers) when resources are abundant, thus adapting computational power requirements to available resources.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent performs preliminary clamping of HDR values to LDR range to create the base layer before generating enhancement layers. This preliminary action creates a computationally simple foundation that can be independently decoded at lower precision, while subsequent enhancement layers add detail progressively, reducing the overall computational burden compared to processing full precision data throughout the entire encoding pipeline.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If HDR images are compressed using standard algorithms, then compatibility with existing standards is improved, but artifact generation increases

Engineering Contradiction:
ImprovecompatibilityVSAvoidcompression artifacts
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an intermediary representation where HDR images are decomposed into base layer (LDR-compatible) and enhancement layers (HDR-specific details). Standard compression algorithms operate on this intermediary structure, processing the base layer with conventional methods while preserving enhancement layers that contain critical HDR information. This intermediary structure acts as a bridge between standard compression and HDR preservation, reducing artifacts by preventing the loss of exponent and fractional color information that would occur with direct compression.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Manufacturing precision

If HDR image data is stored with full precision, then image quality is improved, but data size increases

Engineering Contradiction:
Improvecolor precisionVSAvoiddata size
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent segments full-precision HDR data (96 bits per pixel) into separate components: base layer (24 bits), enhancement layers (variable bit depth), and exponent data (8 bits). This segmentation allows selective compression and discarding of less critical components while preserving essential HDR information. The fractional color data in enhancement layers can be stored at reduced precision (e.g., 4-8 bits instead of 16-32 bits) with minimal perceptual impact, significantly reducing overall data size while maintaining color precision where it matters most.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS8237865B2Multi-compatible low and high dynamic range and high bit-depth texture and video encoding system
Publication Date: 2012.08.07 TRELLIS EURO SRL
  • US8237865B2 patent drawing
  • US8237865B2 patent drawing
  • US8237865B2 patent drawing

AI summary

A method of processing image data includes generating image data including luminance and chrominance data representing a selected object, separating the luminance and chrominance data, storing the separated luminance and chrominance data in corresponding separate spaces in memory, and separately compressing the stored luminance and chrominance data.