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Embedding Text Alternatives in Images Using Photo Metadata

This session will provide an introduction to photo metadata and a practical guide on how to deliver high quality accessible image content. Presentation will include: I. Introduction to Photo Metadata A. What is photo metadata? Set of data providing information about an image Allows transportation of information within an image file Is understood by software providers and human users B. What are the benefits? Provides structure for precise and reliable data Smooths image workflows and operations Improves online and offline search and discovery C. Who uses photo metadata? News agencies Photographers Publishers Museums Galleries Image archives Libraries D. Where is it stored? Internally – embedded in image files (DNG, PNG, and TIFF) Externally – digital asset management systems (DAMs) or sidecar files II. New and Existing IPTC Photo Metadata Properties A. Alt Text (Accessibility) - New Property Brief textual description of the purpose and meaning of an image Accessed by assistive technology or displayed when image disabled in browser Target is 125 characters, not to exceed 250 characters Complies with requirements for WCAG Success Criterion 1.1 Text Alternatives B. Extended Description (Accessibility) - New Property More detailed textual description of the purpose and meaning of an image Elaborates on information provided by Alt Text (Accessibility) property No character limitation. Not required if Alt Text (Accessibility) is deemed to be sufficient Complies with requirements for WCAG Success Criteria 1.1 Text Alternatives C. Headline, Description/Caption, Description Writer - Existing Related IPTC Properties Headline: Brief synopsis or summary of the contents of the image Description/Caption: Who, what, when, where, why, and how of an image Description Writer: Identifier, name of person(s) involved in writing description III. Overview of WCAG Success Criterion 1.1 Text Alternatives A. Purpose of Text Alternatives Ensure all non-text content is available in electronic text format Describe content, purpose, and function of an image Make non-text content “programmatically determinable” B. Quick Tips for Alt Text Begin with the primary focus or central subject of the image Keep it short (125 characters, no more than 250 characters) Describe relevant details that relate to the purpose or meaning of the image C. Quick Tips for Extended Description Do not repeat information already described in the alt text Do not repeat information already available in nearby text on the page Elaborate on details related to the image content, purpose, and function D. Incorporating Context into Text Alternatives. Surrounding text Groups of images Audience Reading level E. HTML Image Attributes for Text Alternatives Creates a holding space for an image, must contain and Provides the image source location or file name Provides a brief text alternative for an image Specifies location information for a more detailed description IV. How to Apply Photo Metadata to Image Workflows and Operations A. Why It’s Important to Prioritize Human-Generated Descriptions Importance of humans writing for humans Update on quality and applications for image recognition technology Museum Case Study: Cooper Hewitt and Coyote Pics B. How to Manage Digital Collection Backlogs Decide on internal or external approach, as well as timeline Steps to add embedded metadata for Alt Text and Extended Description How to extract image accessibility photo metadata for HTML How to use “Lang Alt” metadata to embed multiple languages C. Steps for Establishing Born-Accessible Image Workflows Assemble an image accessibility working group and task force Comprehensive map of internal and external image metadata ecosystem Teach teams how to implement Apple, Google, Microsoft, and Adobe programs Establish new standards and requirements for image creators  
  • Higher Education
  • Information & Communications Technology
  • Media & Publishing
  • Research & Development
  • Marketing
Audience Level
Session Summary (Abstract)
Update on IPTC’s new Alt Text and Extended Description properties added to the IPTC photo metadata standard in Autumn 2021. This session will explore how image providers and licensors can use embedded metadata in image files to scale human-generated descriptions, manage existing digital backlogs, and deliver born-accessible images.  
Session Type
General Track  
  • Blind/Low Vision
  • Digital Accessibility
  • Emerging Technologies
  • Evaluation & Remediation
  • Web


  • Caroline Desrosiers

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