Rec. ITU-T T.701.11 (09/2020) Guidance on text alternatives for images
Summary
History
FOREWORD
Table of Contents
Introduction
1 Scope
2 Normative references
3 Definitions
     3.1 Terms defined elsewhere
     3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 Text alternatives for images
     6.1 Uses of text alternatives
     6.2 Presenting text alternatives
          6.2.1 General
          6.2.2 Text alternatives within the main body of text
          6.2.3 Primary alternative text
          6.2.4 Secondary alternative text
7 Procedure for creating text alternatives
8 Identifying the types of image
     8.1 General
     8.2 Drawings
     8.3 Photographs
     8.4 Diagrams
     8.5 Maps
     8.6 Computer-generated illustrations
     8.7 Composite images
     8.8 Identifying image type in text alternatives
          8.8.1 Identifying the image type of single images
          8.8.2 Identifying image type of composite images with separately addressable components
9 Identifying the purpose of the image
     9.1 Introduction to purposes
     9.2 Informative purposes
     9.3 Control purposes
     9.4 Decorative purposes
          9.4.1 Decorative images that convey affective information
          9.4.2 Decorative images with minimal information value
     9.5 Formatting purposes
     9.6 Identifying purpose in text alternatives
          9.6.1 Describing the purpose
          9.6.2 Stating the purpose briefly
          9.6.3 Avoiding redundancy with captions
          9.6.4 Considering the context of use
          9.6.5 Considering both objective and subjective purposes
          9.6.6 Text alternatives for images used for formatting purposes
          9.6.7 Further information for images used for informative purposes
          9.6.8 Further information for images used for control purposes
10 Identifying the image components
     10.1 Images and image components
     10.2 Text components
     10.3 Uniquely identifying image components
     10.4 Structuring information about images and their components
     10.5 Dealing with image complexity
          10.5.1 Use of image components
          10.5.2 Textual information in images
          10.5.3 Information about whole images
          10.5.4 Information about image components
11 Identifying the information (content) presented by the image
     11.1 Content of an image or its components
     11.2 Subjective content
     11.3 Objective content
     11.4 Relationship content
          11.4.1 Relationships
          11.4.2 Actions
          11.4.3 Logical relationships
          11.4.4 Temporal relationships
          11.4.5 Physical (spatial) relationships
     11.5 Interaction content
     11.6 Analysing the information presented by an image
12 Evaluating the importance of the information about the image
     12.1 Importance is context dependent
     12.2 Importance
          12.2.1 Levels of importance
          12.2.2 Essential information
          12.2.3 Significant information
          12.2.4 Helpful information
          12.2.5 Not important information
     12.3 Textual content in images
     12.4 Using importance to allocate information to text alternatives
          12.4.1 Including subjective information in text alternatives
          12.4.2 Including objective information in text alternatives
          12.4.3 Including relationship information in text alternatives
          12.4.4 Including information on associated activities in text alternatives
          12.4.5 Dealing with large amounts of essential information
          12.4.6 Placing text alternatives in the main body of text
          12.4.7 Handling conflicting information
13 Compose the text alternatives
     13.1 Composition
     13.2 Organizing the information
          13.2.1 Eliminating duplications
          13.2.2 Fitting into the context of use of the image
          13.2.3 Independence of importance from order
     13.3 Wording text alternatives
          13.3.1 Flow with the document content
          13.3.2 Style
          13.3.3 Conciseness and readability
     13.4 Creating text alternatives
14 Evaluate the text alternative
     14.1 The range of evaluation issues
     14.2 The range of evaluation methods and testers
Appendix I   Further elaboration of objective content of images
     I.1 General
     I.2 Characteristics of the image or image component
          I.2.1 Elaborating on physical objects
          I.2.2 Elaborating on people
          I.2.3 Elaborating on perceptual objects or persons
          I.2.4 Elaborating on artistic characteristics
          I.2.5 Elaborating on locations/settings/places
          I.2.6 Elaboration on quantities
     I.3 Some temporal properties of images or image components
          I.3.1 Introduction to temporal properties
          I.3.2 Elaborating about time periods
          I.3.3 Elaborating about events/activities
          I.3.4 Elaborating on states
Appendix II   Further considerations for particular types of images
     II.1 Further considerations for particular types of drawings and photographs
          II.1.1 Portraits
          II.1.2 Symbolic images
          II.1.3 Images of text
          II.1.4 Images used to label other information
          II.1.5 Groups of images conveying a single piece of information
          II.1.6 Icons and other control images
          II.1.7 Images used with a fully descriptive caption
          II.1.8 Images that are fully described in the main text
     II.2 Further considerations for diagrams and maps
          II.2.1 Assembly, component and similar diagrams
          II.2.2 Flow and relationship diagrams
          II.2.3 Graphs and other representations of numerical data
          II.2.4 Maps and other images with active areas
     II.3 Background images
Bibliography