ISO/IEC 29170-2:2015/Amd 1:2020 – Advanced Image Coding Evaluation Update
Overview
ISO/IEC 29170-2:2015/Amd 1:2020 is an international amendment to the advanced image coding and evaluation standard, specifically addressing nearly lossless coding for high dynamic range (HDR) media and image sequences. This amendment updates the evaluation procedure parameters, optimizing the assessment of image quality where compression artifacts are minimal but perceptible.
Developed by ISO and IEC Joint Technical Committee ISO/IEC JTC 1/SC 29, this amendment ensures robust measurement criteria for coding systems working with HDR and wide color gamut content. The evaluation procedure focuses on subjective testing, employing psychophysical methods to discern observer perception differences between original and reconstructed images or sequences.
Key Topics
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Nearly Lossless Coding: Enhancements to evaluation procedures that focus on minor yet visually identifying differences between original and compressed images, especially for HDR content.
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High Dynamic Range Media: Expands assessment parameters for images and sequences with a larger range of luminosity, greater shadow and highlight detail, and more precise color representation versus standard dynamic range (SDR).
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Image Sequences: Incorporates evaluation methods for testing image sequences, including panning techniques and cropping procedures that isolate potential compression artifacts over time.
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Forced-Choice Comparison Tests: Utilizes side-by-side image presentation with forced-choice paradigms designed to establish statistically meaningful perceptual thresholds between reference and test images.
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Viewing Conditions: Specifies calibration and environmental requirements for displays, accounting for HDR brightness levels exceeding 300 cd/m² and consistent ambient lighting following ISO 3664 guidelines.
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Sensory Feedback in Testing: Introduces provision for non-intrusive sensory cues (visual, audial, or haptic) to indicate correct or incorrect observer responses during testing without biasing outcomes.
Practical Applications
This standard amendment provides essential methodologies for:
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Display Manufacturers: To certify and optimize coding algorithms for HDR-capable televisions and monitors ensuring efficient compression without visual quality loss.
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Codec Developers: To assess nearly lossless compression techniques more accurately, particularly for HDR and wide color gamut content used in broadcasting, streaming, and digital cinema.
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Quality Assurance Teams: To implement standardized subjective testing protocols that reliably detect minimal visual impairments introduced by compression across various display technologies.
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Research & Development: Supporting experimental workflows both with HDR hardware processing and software-based display-independent evaluation.
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Multimedia Content Producers: To evaluate bit-rate savings vs perceptual quality trade-offs in modern HDR workflows, contributing to improved end-user experience in high-fidelity visual content.
Related Standards
- ISO/IEC 29170-1: Advanced image coding and evaluation – Part 1: General evaluation procedures.
- ITU Recommendations ITU-R BT.709 & BT.1886: Standard dynamic range and electro-optical transfer functions.
- IEC 61966-2-1 (sRGB): Standard color space for SDR imaging.
- ISO 3664: Viewing conditions for color-imaged material, providing ambient light and calibration parameters.
- ISO/IEC 29170 series: General suite covering methods and metrics for advanced image coding assessment.
Keywords: ISO/IEC 29170-2 Amendment 1, nearly lossless coding, high dynamic range, HDR image sequences, image coding evaluation, advanced image compression, subjective testing, wide color gamut, display calibration, psychophysical image quality assessment, forced choice test methods, ISO image standards.