ISO/IEC 14496-22:2009 信息技术 音频-可视对象的编码 第22部分：开放字体格式

标准编号：ISO/IEC 14496-22:2009

中文名称：信息技术 音频-可视对象的编码 第22部分：开放字体格式

英文名称：Information technology — Coding of audio-visual objects — Part 22: Open Font Format

发布日期：2009-08

标准范围

ISO/IEC 14496-22:20 09规定了开放字体格式（OFF）规范，TrueType？和紧凑字体格式（CFF）大纲格式，以及TrueType提示语言。它引用了TrueType和PostScript，因为Open Font Format字体结合了这两种技术。多媒体应用需要广泛的媒体相关标准。除了典型的音频和视频应用，多媒体演示还包括支持世界上所有语言的可扩展2D图形和文本。可缩放多媒体内容的忠实再现需要包括可缩放字体技术在内的附加组件。开放字体格式是TrueType字体格式的扩展，增加了对PostScript字体数据的支持。OFF字体和支持OFF字体的操作系统服务为用户提供了一种安装和使用字体的简单方法，无论字体包含TrueType轮廓还是CFF（PostScript）轮廓。Open Font Format实现了以下目标:更广泛的多平台支持；对国际字符集的出色支持；出色的字体数据保护；更小的文件大小，使字体分发更有效；对高级印刷控制的出色支持。后记？OFF字体中包含的数据可以直接光栅化或转换为TrueType outline格式以进行渲染，具体取决于主机操作系统中安装了哪些光栅化器。但是用户模型是一样的:OFF字体只是工作。用户不需要知道OFF字体中轮廓数据的类型。字体创建者可以使用他们认为为他们的工作提供最佳功能的任何轮廓格式，而不必担心限制字体的可用性。OFF字体可以包括OFF布局表，允许字体创建者设计更广泛的国际和高-结束印刷字体。关闭布局表包含有关字形替换、字形定位、对齐和基线定位的信息，使文本处理应用程序能够改进文本布局。与TrueType字体一样，OFF字体允许使用Unicode编码处理大型字形集。这种编码允许广泛的国际支持，以及对印刷字形变体的支持。此外，OFF字体可能包含数字签名，这使得操作系统和浏览应用程序能够在使用字体文件（包括在web文档中获得的嵌入式字体文件）之前识别它们的来源和完整性。此外，字体开发者可以在OFF字体中编码嵌入限制，这些限制不能在开发者签名的字体中被改变。

ISO/IEC 14496-22:2009 specifies the Open Font Format (OFF) specification, the TrueType？ and Compact Font Format (CFF) outline formats, and the TrueType hinting language. It makes references to both TrueType and PostScript, as Open Font Format fonts combine the two technologies.Multimedia applications require a broad range of media-related standards. In addition to the typical audio and video applications, multimedia presentations include scalable 2D graphics and text supporting all languages of the world. Faithful reproduction of scalable multimedia content requires additional components including scalable font technology. The Open Font Format is an extension of the TrueType font format, adding support for PostScript font data. OFF fonts and the operating system services which support OFF fonts provide users with a simple way to install and use fonts, whether the fonts contain TrueType outlines or CFF (PostScript) outlines.The Open Font Format addresses the following goals:

• broader multi-platform support;
• excellent support for international character sets;
• excellent protection for font data;
• smaller file sizes to make font distribution more efficient;
• excellent support for advanced typographic control.

PostScript？ data included in OFF fonts may be directly rasterized or converted to the TrueType outline format for rendering, depending on which rasterizers have been installed in the host operating system. But the user model is the same: OFF fonts just work. Users will not need to be aware of the type of outline data in OFF fonts. And font creators can use whichever outline format they feel provides the best set of features for their work, without worrying about limiting a font's usability.OFF fonts can include the OFF Layout tables, which allow font creators to design broader international and high-end typographic fonts. The OFF Layout tables contain information on glyph substitution, glyph positioning, justification, and baseline positioning, enabling text-processing applications to improve text layout.As with TrueType fonts, OFF fonts allow the handling of large glyph sets using Unicode encoding. Such encoding allows broad international support, as well as support for typographic glyph variants.Additionally, OFF fonts may contain digital signatures, which enable operating systems and browsing applications to identify the source and integrity of font files, including embedded font files obtained in web documents, before using them. Also, font developers can encode embedding restrictions in OFF fonts which cannot be altered in a font signed by the developer.

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