Overview
ISO/IEC 24790:2017/Amd 1:2022 is an important international standard published by ISO and IEC that addresses the measurement of image quality attributes for hardcopy output specifically focusing on monochrome text and graphic images produced by office equipment. This amendment updates key measurement methodologies to improve consistency and accuracy in evaluating print quality attributes like background darkness, mottle, graininess, and banding.
Developed by the Joint Technical Committee ISO/IEC JTC 1, Subcommittee SC 28 on office equipment, this standard provides uniform procedures for assessing the visual quality of printed monochrome images, essential for manufacturers, quality control labs, and print professionals. The document enhances image quality measurement processes with precise formulations and introduces colorimetric techniques aligned with sRGB color space conversion for scanner outputs, facilitating consistent evaluation of black-and-white prints.
Key Topics
- Image Quality Attributes: Detailed methods to quantify essential attributes such as background darkness, mottle, graininess, and banding in monochrome hardcopy outputs.
- Reflectance Factor Measurement: Utilization of visual reflectance factors (R_v) derived from user-selected regions to establish print quality boundaries and profiles.
- Scanner Data Processing: Converts red, green, and blue scanner output values into linearized sRGB color space based on IEC 61966-2-1 and ISO 13655 standards for improved colorimetric accuracy.
- Wavelet Transform Techniques: Applies advanced image processing methods like wavelet transforms to filter and analyze pixel variance across tiles, giving precise metrics of graininess and banding.
- Conformance Test Charts: Utilizes standardized test patterns for system conformance testing to calibrate and verify measurement devices ensuring repeatability and reliability.
- Software and Tools: References to specialized system conformance testing software tools compatible with LabVIEW, MATLAB Compiler Runtime, and Visual C++ for automated quality analysis.
Applications
ISO/IEC 24790:2017/Amd 1:2022 serves as a critical reference for multiple practical applications:
- Office Equipment Manufacturers: Assists in product development, quality assurance, and benchmarking of printers, copiers, and scanners producing monochrome hardcopy images.
- Print Quality Control: Enables print service providers and quality labs to standardize evaluation procedures to maintain consistent output quality for documents and graphics.
- Scanner Calibration: Guides device calibration using standardized colorimetric measurement approaches ensuring accuracy when converting scanner RGB data to linearized sRGB values.
- R&D in Imaging Technology: Supports research and development in imaging technologies aimed at improving the visual quality of monochrome hardcopy by providing validated measurement methodologies.
- Industry Compliance: Helps organizations comply with international standards and ensures interoperability and acceptance of office equipment products in global markets.
Related Standards
This amendment references and aligns with related international standards and technical documents:
- ISO 13655: Graphic Technology - Specifies spectral measurement and colorimetric computations crucial for graphic arts and image analysis.
- IEC 61966-2-1: Multimedia Systems and Equipment - Defines the sRGB color space standard used for color management and scanner output conversion.
- ISO 14524: Reflectance Factor Measurement - Describes methods for obtaining optical density and reflectance factors, foundational for image quality assessment in this context.
- ISO/IEC Directives - Governance on the editorial and procedural rules that ensure consistent development and maintenance of ISO/IEC standards.
By adhering to ISO/IEC 24790:2017/Amd 1:2022, stakeholders involved in office equipment manufacturing, printing, and scanning can achieve more accurate, reproducible, and internationally recognized evaluation of monochrome image quality, ultimately enhancing the end-user experience and product integrity.