PDF替代文本
Figures in a PDF document need to have alternate text in order for a screen reader
to describe what the image is to someone who may be visually impaired. 确保
images in the document either have alternate text or are marked as an artifact. To
do this, do ONE of the following:
- Select 图替代文本 in the 可访问性检查器 面板，然后从 选项 menu. Add alternate text as prompted in the 设置备用文本 对话框.
- Use the Tags panel to add alternate text from images in the PDF.
- 打开 内容 panel and right-click (Windows) or Ctrl-click (Mac OS) the content that you want 标记:标记为人工制品. 然后,选择 创建工件 从上下文菜单中. (要显示 内容 面板中,选择 View > 显示/隐藏 > 导航窗格 > 内容.)
Screen readers used by someone who may be visually impaired do not read the alternate
嵌套元素的文本. Therefore, don’t apply alternate text to nested elements.
To remove alternate text from nested elements:
- Choose View > 显示/隐藏 > 导航窗格 > Tags.
- Right-click (Windows) or Ctrl-click (Mac OS) a nested element in the Tags 面板并选择 属性 从上下文菜单中.
- 把两个 替代文本 and the text to which it's applied 从 对象属性 对话框，然后单击 Close.
When you have alternate text on a page, you must always make sure that the alternate text is an acceptable alternate representation of content on that page. 如果一个元素 has alternate text, but then doesn’t contain any page content, there is no way to determine which page it is actually on. If the 屏幕阅读器选项 in the Reading preferences is not set to read the entire document, the screen reader will never read 替代文本, so it’s better to remove it.
- Right-click (Windows) or Ctrl-click (Mac OS) an item to check.
- 打开它 Tags panel. (要显示 Tags 面板中,选择 View > 显示/隐藏 > 导航窗格 > Tags.)
- 删除 替代文本 从 Tags panel for any nested item that has no page content.
Alternate text can’t hide an annotation. If an annotation is nested under a parent element with alternate text, then the screen readers do not see it. 要解决这个问题，请删除 替代文本 从 nested elements. 要做到这一点:
- Choose View > 显示/隐藏 > 导航窗格 > Tags.
- Right-click (Windows) or Ctrl-click (Mac OS) a nested element in the Tags 面板并选择 属性 从上下文菜单中.
- Remove 替代文本 从 对象属性 对话框，然后单击 OK.
If this error occurs, it means there is another element on your page other than a figure that will require alternate text, such as some multimedia, an annotation, or 3D模型. 确保 alternate text is always an alternate representation for 页面上的内容. 如果一个元素 has alternate text, but does not contain any page content, there is no way to determine which page it is on. If the 屏幕阅读器选项 in the Reading preferences is not set to read the entire document, then screen readers don't read 替代文本. 删除替代文本:
- Choose View > 显示/隐藏 > 导航窗格 > Tags.
- Right-click (Windows) or Ctrl-click (Mac OS) a nested element in the Tags 面板并选择 属性 从上下文菜单中.
- Remove 替代文本 从 对象属性 对话框，然后单击 OK.