JEIDA-49-1998

Digital Still Camera Image File Format Standard

(Exchangeable image file format for Digital Still Camera : Exif)

Version 2.1

Revision History

This "Digital Still Camera Image File Format Standard" is issued as a standard for the image file format (Exif: Exchangeable image file format) used in digital still cameras and related systems. It was first published in October 1996 as Version 1.0 . Then in May 1997, Version 1.1 was issued, adding specifications for optional attribute information as well as stipulations relating to format implementation, in addition to the mandatory specifications of Version 1.0.

The desire for a uniform file format standard for the image data stored by digital still cameras has increased as these cameras have grown in popularity. At the same time, with the broadening application of this technology, a similar desire has arisen for uniformity of the attribute information that can be recorded in a file.

The Version 2.0 makes improvements to the Exif format for greater ease of use, while allowing for backward compatibility with products of manufacturers currently implementing Exif Version 1.x or considering its future implementation. The present Version 2.1 contains Recommended Exif Interoperability Rules.

The following additions and changes are made from Version 1.1 to Version 2.1.

[Additions]

13. Audio file format specification

14. JPEG compressed thumbnail specification

15. Chrominance sampling method Y:Cb:Cr = 4:2:0.

16. Tags for FlashPix transformation

17. Additional tags for picture-taking conditions

18. APP2 marker segment specification for FlashPix extensions

19. Definition of color space information

20. Addition of Interoperability IFD (Version 2.1)

21. Addition of [Appendix D.1 Recommended Exif Interoperability Rules ExifR98] (Version 2.1)

[Changes]

22. Combined into one chapter the separate chapters on the Exif file specification and implementation specification (Exif-1).

23. Removed the limitation on number of pixels (multiples of 8 and 16) to allow for expanded implementation.

24. Content of ExifVersion Tag is changed into 2.1

Contents

Revision History

Contents

1. General

1.1. Objectives

1.2. Scope and Abbreviation

1.3. Format Structure

1.4. Exif Image File Specification

1.5. Exif Audio File Specification

1.6. Relation between Image and Audio File Specification

1.7. Presupposed Systems and Compatibility

2. Exif Image File Specification

2.1. Outline of the Exif Image File Specification

2.2. Format Version

2.3. Definition of Glossary

2.4. Specifications Relating to Image Data

2.4.1. Number of Pixels

2.4.2. Pixel Aspect

2.4.3. Pixel Composition and Sampling

2.4.4. Image Data Arrangement

2.5. Basic Structure of Image Data

2.5.1. Basic Structure of Primary Image Data

2.5.2. Basic Structure of Uncompressed RGB Data

2.5.3. Basic Structure of YCbCr Uncompressed Data

2.5.4. Basic Structure of JPEG Compressed Data

2.5.5. Basic Structure of Thumbnail Data

2.6. Tags

2.6.1. Features of Attribute Information

2.6.2. IFD Structure

2.6.3. Exif-specific IFD

2.6.4. TIFF Rev. 6.0 Attribute Information

2.6.5. Exif IFD Attribute Information

2.6.6. GPS Attribute Information

2.6.7. Interoperability IFD Attribute Information

2.6.8. Tag Support Levels

2.7. JPEG Marker Segments Used in Exif

2.7.1. JPEG Marker Segments

2.7.2. Interoperability Structure of APP1 in Compressed Data

2.7.3. Interoperability Structure of APP2 in Compressed Data

2.8. Data Description

2.8.1. Stipulations on Compressed Image Size

2.8.2. Stipulations on Thumbnails

2.8.3. File Name Stipulations

2.8.4. Byte Order Stipulations

3. Exif Audio File Specification

3.1. Outline of the Exif Audio File Specification

3.2. Format Version

3.3. Definition of Terms

3.4. Specifications Relating to Audio Data

3.4.1. Sampling Frequency

3.4.2. Bit Size

3.4.3. Channels

3.4.4. Compression Schemes

3.5. Basic Structure of Audio Data

3.5.1. Basic Structure of WAVE Form Audio Files

3.5.2. Basic Structure of PCM Audio Data

3.5.3. Basic Structure of m-Law Audio Data

3.5.4. Basic Structure of IMA-ADPCM Audio Data

3.6. Chunks Used

3.6.1. WAVE Form Audio File Basic Chunks

3.6.2. LIST Chunk and INFO List

3.6.3. Chunks for Attribute Information Specific to Exif Audio Files

3.7. Data Description

3.7.1. File Naming Stipulation

app.A Image File Description Examples

A.1 Uncompressed RGB File

A.2 Uncompressed YCbCr File

A.3 JPEG Compressed (4:2:2) File

A.4 JPEG Compressed (4:2:0) File

app. B Audio File Description Examples

B.1 PCM Audio Data

-Law Audio Data

B.3 IMA-ADPCM Audio Data

app. C APEX Units

app. D Recommended Implementation Example

D.1 Recommended Directory Name Usage Examples

D.2 Recommended File Naming Usage Examples

D.3 Recommended File Operation Usage Examples

D.4 Interoperability "Recommended Exif Interoperability Rules" (ExifR98)

app. E Color Space Guidelines

E.1 sRGB

E.2 Tone Reproduction (Brightness and Contrast)

E.3 Luminance/Chrominance and RGB Transformation

app. F Notes on Conversion to FlashPix

F.1 Converting Image Data

F.2 Converting Tag Data

F.3 Converting to FlashPix Extensions (APP2)

JEIDA-49-2-1998

「Design rule for Camera File system(DCF)　」

Dcfe.pdf(142KB)　　　　　

Dcfe.zip(114KB)　　　　　

Background to this standard

The Exif image file format standard was established with the aim of realizing a common format for the image files used with digital still cameras and other related equipment, making these products more convenient for end users.

With the rapidly growing popularity of digital still cameras, there are increasing demands for file interchangeability, which will allow images captured on one camera to be viewed on another, or output directly to a printer. ExifR98 is a set of compatibility recommendations designed to meet such needs, by strictly defining the range of Exif application, and by setting out detailed rules for recording and playing image files not specified in the Exif format.

In addition, CIFF (Camera Image File Format) lays out rules for directory and file structures, so that a variety of files can be stored and managed efficiently on removable memory media.

The present specification (Design rule for Camera File system, hereinafter DCF) is based on the above recommendations. It was drawn up for the purpose of simplifying the interchange of image files and related files on digital still cameras and other equipment, while supporting today's higher resolution images and large-capacity memory media.

Contents

Background to this standard i

1. Introduction

1.1. Purpose

1.2. Scope

1.3. Glossary

1.4. Definition of characters used in directory and file names

1.5. Approach to playback compatibility

2. Definition of DCF-compatible products

2.1. DCF and recording media

2.2. Configuration of DCF specification

2.3. Classification of functions

2.4. Categories of DCF-compatible equipment

3. DCF media standard

3.1. Directory definition

3.1.1. DCF image root directory

3.1.2. DCF directories

3.1.3. Other directories

Directory example

3.2. File definition

3.2.1. DCF file names

3.2.2. DCF objects

(A) Purpose of DCF objects

(B) Object definition

(D) Object file attributes

(E) Object operation

3.3. DCF basic files

3.3.1. Purpose

3.3.2. Directory, file names and extensions

3.3.3. Images in a DCF basic file

3.3.4. Data structure of a DCF basic main image

(A) Data structure

(B) Data compression

(D) Image aspect ratio

3.3.5. Attribute information

(A) Exif tag structure

(B) Image-related information

(D) Color space

3.3.6. DCF basic thumbnail data structure

(A) Image data format

(B) Compressed data

(D) Image aspect ratio

3.3.7. Image data format in DCF basic files

3.4. DCF thumbnail files

3.4.1. Purpose

3.4.2. Directory, file name and extension

3.4.3. Image data structure

(A) Data format

(B) Compressed data specification

(D) Image aspect ratio

3.4.4. Attribute information

(A) Exif tag structure

(B) Image-related information

(D) Color space

3.4.5. DCF thumbnail file data structure

3.5. Tag requirement levels

3.5.1. DCF basic file attribute information

3.5.2. DCF thumbnail file attribute information

File structure example

4. Writer specification

4.1. Directories

4.1.1. Creating directories

(A) DCF image root directory

(B) DCF directories

4.1.2. Deleting directories

4.2. Files

4.2.1. Creating files

(A) Image files

(B) DCF thumbnail files

(D) Files without a DCF file name

4.2.2. File number

4.2.3. Deleting files

(A) DCF objects

(B) Files that are not DCF objects

5. Reader 1 specification

5.1. Directories (common to Reader 1 and 2)

5.1.1. Playback

(A) Playback scope

(B) Playback method

5.1.2. Deletion

5.2. Files

5.2.1. Playback

(A) Playback scope

(B) Playback method (common to Reader 1 and 2)

(D) Handling of color-related tags (common to Reader 1 and 2)

5.2.2. Deletion (common to Reader 1 and 2)

(A) DCF objects

(B) Files that are not DCF objects

5.3. Directory number and file number display (common to Reader 1 and 2)

6. Reader 2 specification

6.1. Directories

6.1.1. Playback

6.1.2. Deletion

6.2. Files

6.2.1. Playback

(A) Playback scope

(B) Playback method

(D) DCF basic file identification

(E) Handling of color-related tags

6.2.2. Deletion

6.3. Directory number and file number display

7. Other precautions

7.1. Naming directories under the DCF image root directory

(A) When lower-case letters are used in a directory name

(B) When directory numbers are duplicated across DCF directories

7.2. Naming of files in a DCF directory

(A) When lower-case letters are used in the file name

(B) When file numbers are duplicated across DCF basic files

7.3. Updating of tag data when saving

7.3.1. Handling of date tags

7.3.2. Handling of Make, Model, and Software tags

7.4. DCF object bulk operations

Annex A DCF applicable media

Annex B Data validation

A. Validation method

B. Compatibility testing policy

Annex C Relation to JPEG and Exif standards