ISO/IEC 15444-5:2021 信息技术 JPEG2000图象编码系统 第5部分：参考软件

标准编号：ISO/IEC 15444-5:2021

中文名称：信息技术 JPEG2000图象编码系统 第5部分：参考软件

英文名称：Information technology — JPEG 2000 image coding system — Part 5: Reference software

发布日期：2021-10

标准范围

ISO/IEC 15444-5:20 21建议。ITU-T T.800 ISO/IEC 15444-1定义了一组用于编码连续色调、双层、灰度或彩色数字静止图像的无损和有损压缩方法。该推荐国际标准提供了Rec的三种独立创建的软件参考实现。ITU-T T.800 ISO/IEC 15444-1，以帮助Rec的实施者。ITU-T T.800 ISO/IEC 15444-1测试和理解其内容。这些软件包有JASPER、JJ2000和OPENJPEG。该推荐性国际标准还提供了Rec的独立创建的软件参考实现。ITU-T T.814 ISO/IEC 15444-15，其规定了可以用来代替Rec的块编码算法的高吞吐量(HT)块编码算法。ITU-T T.800 ISO/IEC 15444-1，为了帮助Rec的实施者。ITU-T T.814 ISO/IEC 15444-15测试和理解其内容。包裹是TT。该推荐国际标准另外提供了用于解析Rec中指定的JP2文件格式的独立创建的软件参考实现。ITU-T T.800 ISO/IEC 15444-1和Rec中规定的JPH文件格式。ITU-T T.814 ISO/IEC 15444-15，包是代码流解析器。本推荐国际标准没有定义JPEG 2000图像编码系统的任何附加部分。每个版本的J2K参考软件都包含源代码，可以对其进行编译以提供以下功能:-从选定的广泛可用的图像格式转码为JPEG 2000码流。-从选定的广泛可用的图像格式转码为JP2文件格式。-选择广泛的JPEG 2000编码选项（如每个参考软件中所述）。-从JPEG 2000码流解码为一系列选定的广泛可用的图像格式。-处理JP2文件以提取JPEG 2000码流，用于解码和转换成一系列选定的广泛可用的图像格式。-从JP2文件中提取元数据的能力，包括图像标题框和色彩空间的内容。-对JP2文件进行解码，所述JP2文件使用受限ICC方法的基于三分量矩阵的形式来指定颜色空间并将解码的图像数据转换到sRGB颜色空间以供显示，包括将所有解码分量有限上采样到相同分辨率。-使用受限ICC方法的单色形式来指定颜色空间的JP2文件的解码以及将解码的图像数据转换为JP2文件内定义的基于sRGB的灰度空间格式。-使用sYCC颜色空间的JP2文件的解码以及将解码的图像数据转换到sRGB颜色空间以用于显示，包括将所有解码的分量上采样到相同的分辨率。-一些有助于评估和测试的附加工具。TT HTJ2K参考软件包含源代码，可以对其进行编译以提供以下功能:-从HTJ2K码流解码为一系列选择的广泛可用的图像格式。codestream-parser参考软件包含源代码，可以提供以下功能:-解析JP2文件格式；-JPH文件格式的解析。该参考软件旨在用作JPEG 2000其他实现的测试和验证工具，并帮助理解Rec。ITU-T T.800 ISO/IEC 15444-1和建议。ITU-T T.814 ISO/IEC 15444-15。

ISO/IEC 15444-5:2021 Rec. ITU-T T.800 ISO/IEC 15444-1 defines a set of lossless and lossy compression methods for coding continuous-tone, bi-level, greyscale or colour digital still images. This Recommendation International Standard provides three independently created software reference implementations of Rec. ITU-T T.800 ISO/IEC 15444-1, in order to assist implementers of Rec. ITU-T T.800 ISO/IEC 15444-1 in testing and understanding its content. The packages are JASPER, JJ2000 and OPENJPEG.
This Recommendation International Standard also provides an independently created software reference implementation of Rec. ITU-T T.814 ISO/IEC 15444-15, which specifies a high-throughput (HT) block coding algorithm that can be used in place of the block coding algorithm of Rec. ITU-T T.800 ISO/IEC 15444-1, in order to assist implementers of Rec. ITU-T T.814 ISO/IEC 15444-15 in testing and understanding its content. The package is TT.
This Recommendation International Standard additionally provides an independently created software reference implementation for parsing of a JP2 file format specified in Rec. ITU-T T.800 ISO/IEC 15444-1 and a JPH file format specified in Rec. ITU-T T.814 ISO/IEC 15444-15, The package is Codestream-parser.
This Recommendation International Standard does not define any additional part of the JPEG 2000 image coding system.
Each version of the J2K reference software contains source code, which can be compiled to provide the following functionality:
– Transcoding from selected, widely available image formats into a JPEG 2000 codestream.
– Transcoding from selected, widely available image formats into the JP2 file format.
– Selection of a wide range of JPEG 2000 encoding options (as documented in each reference software).
– Decoding from a JPEG 2000 codestream to a range of selected widely available image formats.
– Processing of a JP2 file to extract a JPEG 2000 codestream for decoding and conversion to a range of selected widely available image formats.
– The ability to extract metadata from a JP2 file, including the contents of the Image Header box and the colour space.
– The decoding of JP2 files that use the three-component matrix-based form of the restricted ICC method for the specification of colour space and the conversion of the decoded image data to the sRGB colour space for display, including limited upsampling of all decoded components to the same resolution.
– The decoding of JP2 files that use the monochrome form of the restricted ICC method for the specification of colour space and the conversion of the decoded image data to the sRGB based greyscale space as defined within the JP2 file format.
– The decoding of JP2 files that use the sYCC colour space and the conversion of the decoded image data to the sRGB colour space for display, including upsampling of all decoded components to the same resolution.
– Some additional tools to help with evaluation and testing.
The TT HTJ2K reference software contains source code, which can be compiled to provide the following functionality:
– Decoding from a HTJ2K codestream to a range of selected widely available image formats.
The codestream-parser reference software contains source code, which can provide the following functionality:
– Parsing of JP2 file format;
– Parsing of JPH file format.
The reference software is intended for use as a testing and validation tool for other implementations of JPEG 2000, and to help in the understanding of Rec. ITU-T T.800 ISO/IEC 15444-1 and Rec. ITU-T T.814 ISO/IEC 15444-15.

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