ISO/IEC 29199-5:2012 情報技術— JPEG XR画像コーディングシステム—パート5：リファレンスソフトウェア | ページ 3

0 Introduction

This part of ISO/IEC 29199 has been developed by ITU-T and ISO/IEC in a collaborative team that is referred to as the Joint Photographic Experts Group (JPEG). It is published as technically-aligned twin text by both organizations (ITU-T and ISO/IEC).

This part of ISO/IEC 29199 provides reference software for ITU-T Rec. T.832 | ISO/IEC 29199-2( Information technology – JPEG XR image coding system – Image coding specification) as an electronic attachment. The reference software is an integral part of this part of ISO/IEC 29199.

Reference software is useful in aiding users of an image coding standard to establish and test conformance and interoperability, and to educate users and demonstrate the capabilities of the associated standard. For these purposes, the accompanying software is provided as an aid for the study and implementation of ITU-T Rec. T.832 | ISO/IEC 29199-2 technology. The reference software includes both encoder and decoder functionality.

0.1 Purpose

The purpose of this part of ISO/IEC 29199 is to provide the following.

• Reference decoder software capable of decoding codestreams (or files) that conform to ITU-T Rec. T.832 | ISO/IEC 29199-2| in amanner that conforms to the decoding process specified in ITU-T Rec. T.832 | ISO/IEC 29199-2.
• Sample encoder software capable of producing codestreams (or files) that conform to ITU-T Rec. T.832 | ISO/IEC 29199-2.

The use of this reference software is not required for making an implementation of an encoder or decoder in conformance to ITU-T Rec. T.832 | ISO/IEC 29199-2. Requirements established in ITU-T Rec. T.832 | ISO/IEC 29199-2 take precedence over the behaviour of the reference software.

0.2 Examples of use

Some examples of uses for the reference decoder software are as follows:

• – As an illustration of how to perform the decoding process specified in ITU-T Rec. T.832 | ISO/IEC 29199-2.
• – As the starting basis for the implementation of a decoder that conforms to ITU-T Rec. T.832 | ISO/IEC 29199-2.
• – For testing the conformance of a decoder implementation with the decoding process specified in ITU-T Rec. T.832 | ISO/IEC 29199-2 (as the values of the samples in all decoded pictures will be identical from all conforming decoder implementations that support the profile and level used in a codestream that conforms to ITU-T Rec. T.832 | ISO/IEC 29199-2, with limited allowances for color sampling format conversions as specified in ITU-T Rec. T.832 | ISO/IEC 29199-2).
• – For (non-exhaustive) testing of the conformance of a codestream (or file) to the constraints specified for codestream (or file) conformance in ITU-T Rec. T.832 | ISO/IEC 29199-2, as the software can detect and report many codestream conformance violations.

  NOTE 1 – However, the lack of the detection of any conformance violation by the reference decoder software should not be considered as definitive proof that the codestream (or file) conforms to all constraints specified for conformance in ITU-T Rec. T.832 | ISO/IEC 29199-2.

Some examples of uses for the sample encoder software are as follows:

• – As an illustration of how to perform an encoding process that produces codestreams (or files) that conform to the constraints specified for codestream (or file) conformance in ITU-T Rec. T.832 | ISO/IEC 29199-2.
• – As the starting basis for the implementation of an encoder that conforms to ITU-T Rec. T.832 | ISO/IEC 29199-2.
• – As a means of generating codestreams (or files) for testing the conformance of a decoder implementation with the decoding process specified in ITU-T Rec. T.832 | ISO/IEC 29199-2.
• – As a means of demonstrating and evaluating examples of the quality that can be achieved by an encoding process that conforms to ITU-T Rec. T.832 | ISO/IEC 29199-2.

  NOTE 2 – However, no guarantee of the quality that will be achieved by an encoder is provided by its conformance to ITU-T Rec. T.832 | ISO/IEC 29199-2, as the conformance of an encoder to ITU-T Rec. T.832 | ISO/IEC 29199-2 is defined only in terms of specified constraints imposed on the syntax of the output of the encoder. In particular, while the sample encoder software may suffice to provide some illustrative examples of what quality can be achieved in conformance to ITU-T Rec. T.832 | ISO/IEC 29199-2, it provides neither an assurance of minimum guaranteed image encoding quality nor maximum achievable image encoding quality.

  NOTE 3 – Similarly, the computational resource characteristics (in terms of program or data memory usage, processing speed, types and characteristics of computational operations, etc.) of the sample software encoder or decoder should not be construed as representative of the typical, minimum or maximum computational resource characteristics to be exhibited by implementations of ITU-T Rec. T.832 | ISO/IEC 29199-2.

0.3 Warranty disclaimer

Regardless of any and all statements made herein or elsewhere regarding the possible uses of the reference software, the following disclaimers of warranty apply to the provided reference software.

• – ITU, ISO, and IEC disclaim any and all warranties, whether express, implied, or statutory, including any implied warranties of merchantability or of fitness for a particular purpose.
• – In no event shall the contributor(s) or ITU, ISO, or IEC be liable for any incidental, punitive, or consequential damages of any kind whatsoever arising from the use of these programs.
• – This disclaimer of warranty extends to the user of these programs and the user's customers, employees, agents, transferees, successors, and assignees.
• – ITU, ISO, and IEC do not represent or warrant that the software is free of infringement of any patents.
• – Commercial implementations of ITU-T Recommendations and ISO/IEC International Standards, including shareware, may be subject to royalty fees to patent holders.
• – Information regarding the common patent policy for ITU-T/ITU-R/ISO/IEC is available at http://www.itu.int/ITU-T/dbase/patent/patent-policy.html .