Digital Photographic Records

Issued November 12, 2003

1.0   PREFACE

As part of the Electronic Records Management (ERM) E-Gov Initiative to improve electronic records management in Federal agencies, and in cooperation with other Federal agencies, NARA is issuing guidance to supplement current requirements in 36 CFR 1228.270 for transferring permanent electronic records to NARA.

This guidance expands currently acceptable formats to enable the transfer of permanent digital photographic records to NARA. The specific requirements below build upon the existing requirements for audiovisual records in 36 CFR 1228.266 and 36 CFR Part 1232, which are applicable where appropriate.

2.0   INTRODUCTION

Digital photography is a priority electronic records format identified by NARA and partner agencies as part of the Electronic Records Management (ERM) initiative, one of the twenty-four E-Gov initiatives under the President's Management Agenda. A major goal of this initiative is to provide the tools for agencies to access electronic records for as long as required and to transfer permanent electronic records to NARA for preservation and future use by government and citizens.

In Fiscal Years 2002 and 2003, NARA worked with several Federal agencies to develop and promulgate transfer guidance for three formats: (1) e-mail with attachments, (2) scanned images of textual records, and (3) records in Portable Document Format (PDF). For more information on NARA's E-Gov ERM Initiative and the completed products, please visit our web site at: http://www.archives.gov/records-mgmt/initiatives/erm-overview.html.

3.0   SCOPE

This guidance applies to digital photographic records that have been appraised and scheduled for permanent retention at NARA. Included under the scope of this guidance are still photographs of natural, real-world scenes or subjects created in support of agency business that are:

• produced from digital cameras (excluding the types of records described below), and
• scanned images of photographic prints, slides, and negatives.

3.1   Inclusions

The guidance applies to master image files of digital photographs ¹ created using medium to high quality resolution settings appropriate for continued preservation. Specific requirements and guidelines for medium quality image resolution are outlined in sections 5.3.3 and 5.3.4. High quality image resolution settings are described in sections 5.3.3.1 and 5.3.4.1.
 

3.2   Exclusions

The following digital photographic records will not be accepted for transfer under this guidance:
 

3.2.1   Low resolution photographs typically created for posting on agency web sites (i.e., all files created at less than 2 megapixels ², or scanned as less than 2000 line files),
 

3.2.2   Digital photographs captured within office automation applications (e.g., word processing, spreadsheet, and presentation applications),
 

3.2.3   Digital photographic records such as aerial photography, and photogrammetric and satellite imagery,
 

3.2.4   Vector-based images, such as records created using graphic arts software or computer-aided design (CAD) applications.

4.0   EFFECTIVE DATES

The effective dates of these requirements are as follows and are based on when the records are created.
 

4.1   November 12, 2003.  The requirements in this guidance (except those cited in 4.2 below) are effective November 12, 2003, for all permanent digital photographic records meeting the provisions of section 3.1.
 

4.2   January 1, 2005.  The additional requirements in sections 5.3 and 5.4 (see below) apply to permanent digital photographic records created on or after January 1, 2005. The effective date of these provisions has been deferred to allow agencies time to implement them:
 

• Image resolution and size specifications for digital camera photographs (section 5.3.3.1)
• Image resolution and size specifications for scanned images of photographs (section 5.3.4.1)
• Restrictions against re-sizing or interpolating digital photographs (section 5.3.5)
• Compression level settings for JPEG files (section 5.3.7.1)
• Transfer of first generation JPEG files (section 5.3.8)
• Additional technical metadata to be supplied with transferred records (section 5.4.4)

5.0   TRANSFER REQUIREMENTS FOR DIGITAL PHOTOGRAPHIC RECORDS

Effective upon promulgation of these requirements, NARA will accept transfers of permanent digital photographic records that meet the specifications of this guidance. The requirements in sections 5.1 through 6.0 list acceptable image file formats, image quality specifications, transfer documentation, and related information on how to transfer these records to NARA.

NARA recognizes that legacy records and records whose disposition is changed from temporary to permanent may present unique circumstances for agencies. Any agency having permanent digital photographic records that do not meet the requirements in this guidance should contact the NARA appraisal archivist assigned to that agency (see section 8.0).

5.1   General Requirements

5.1.1   Digital photographic records acceptable for transfer to NARA must meet the provisions of section 3.1 and shall include still photographs produced by digital cameras and scanned images of photographs.

5.1.2   Digital photographic records must be scheduled for permanent retention and transfer to NARA on a SF 115, Request for Records Disposition Authority. The records must be organized as either a discrete collection of photographs or by agency records series.

5.2   Image File Format
 

5.2.1   NARA will accept digital photographic records in the following file formats and versions. Additional formats may be added in subsequent iterations of this guidance.
 

 

5.2.1.1   Tagged Image File Format (TIFF), in 'II' format, ³ versions 4.0 (April 1987), 5.0 (October 1988), and 6.0 ⁴ (June 1992). Default file extensions include .TIFF and .TIF.
 

5.2.1.2   JPEG ⁵ File Interchange Format (JFIF, JPEG), all versions compliant with International Standards Organization (ISO/IEC) standard 10918-1: Information Technology -- Digital Compression and Coding of Continuous-tone Still Images (1994). Default file extensions include .JPEG, .JFIF, and .JPG.
 

5.2.2   NARA prefers that agencies transfer digital photographic records with file names that use the default file extension for each of the above formats. Records may be accepted that are named according to agency-specific naming conventions (e.g., agency acronym or NARA-assigned record group number) provided the corresponding computer files can be opened and the agency has transferred to NARA adequate documentation describing the file name and format of the files.
 

5.3   Image Quality Specifications
 

5.3.1   Records must be provided as continuous-tone gray scale or color raster images, 8-bit or 16-bit per channel.
 

5.3.2   Color images must be produced in RGB (Red Green Blue) color mode as 24-bit or 48-bit color files.
 

5.3.3   Records created using digital cameras must be captured as 2 megapixel files or greater with a minimum pixel array ⁶ of 1,600 pixels by 1,200 pixels. (Note: image resolution for digital camera files will vary according to the settings of the digital camera and may affect actual pixel dimensions and aspect ratios ⁷ ).
 

 

5.3.3.1   Effective January 1, 2005, digital camera files must be captured as 6 megapixel files or greater with a minimum pixel array of 3,000 pixels by 2,000 pixels. Records produced at this resolution and size are comparable in quality to 35-mm film photographs, which is the minimum quality level for still pictures currently accepted by NARA [see 36 CFR 1228.266(b)].
 

5.3.4   Photographs must be scanned as minimum 2,000 line files ⁸ to approximate a 2 megapixel file according to the following image size and resolution guidelines. (Note: image resolution for scanned images of photographs will vary according to the size of the source document, which may affect actual pixel dimensions and aspect ratios).
 

• Scan an 8" x 10" original (print, slide or negative) at 200 dpi ⁹ to produce a file that is 1,600 x 2,000 pixels.

• Scan a 4" x 5" original (print, slide or negative) at 400 dpi to produce a file that is 1,600 x 2,000 pixels.

• Scan a 35-mm original (print, slide or negative) at 1400 dpi to produce a file that is 1,300 x 2,000 pixels.
  
   

 

5.3.4.1   Photographs scanned after January 1, 2005, must be produced as minimum 3,000 line files ¹⁰ to approximate a 6 megapixel file according to the following image size and resolution guidelines. Records conforming to these guidelines will be comparable in quality to 35-mm film photographs, which is the minimum quality level for still pictures currently accepted by NARA [see 36 CFR 1228.266(b)].
 

• Scan an 8" x 10" original (print, slide or negative) at 300 dpi to produce a file that is 2,400 x 3,000 pixels.

• Scan a 4" x 5" original (print, slide or negative) at 600 dpi to produce a file that is 2,400 x 3,000 pixels.

• Scan a 35-mm original (print, slide or negative) at 2100 dpi to produce a file that is 2,000 x 3,000 pixels.

5.3.5   Effective January 1, 2005, agencies must ensure that digital cameras and scanners produce records with true optical resolution. ¹¹ Resizing images or interpolating ¹² to a higher resolution from a lower resolution for purposes of transfer will not be permitted.
 

5.3.6   NARA will accept digital photographs in TIFF file formats that are compressed using a lossless ¹³ compression method (e.g., LZW, RLE). If available, NARA prefers that agencies transfer uncompressed versions of these files.
 

5.3.7   NARA will accept permanent digital photographs in the JPEG file format, which uses a lossy ¹⁴ compression method, provided the records have been created using at least medium quality ¹⁵ compression settings (or better).
 

 

5.3.7.1   Effective January 1, 2005, agencies must create JPEG files using at least high quality ¹⁶ compression settings (or better).
 

5.3.8   Effective January 1, 2005, agencies must transfer to NARA first generation JPEG files that have not been degraded in quality by multiple revisions and re-saving. Making changes to JPEG files (e.g., altering the image size), and then re-saving them, can result in re-compression of the images, leading to additional data loss and degradation of image quality.
 

5.4   Transfer Documentation

This guidance supplements transfer documentation requirements in 36 CFR 1228.270(e) to ensure that transfers of digital photographic records are clearly identified and described. For all such transfers, agencies must submit a signed Standard Form 258, Agreement to Transfer Records to the National Archives of the United States (SF 258), as required by 36 CFR 1228.272.
 

5.4.1   For each transfer, agencies must supplement the SF 258 with additional information identifying the number of files in the transfer, the size (in bytes) of these files, and the logical arrangement of the files (e.g., by subject or date).
 

5.4.2   Agencies must provide descriptive information about the records (i.e., metadata)¹⁷. NARA prefers that this information be captured for each image in the image header, but will accept transfers of records with this information in the accompanying documentation. Specific information required includes, but is not limited to:
 

 

5.4.2.1   Unique photograph identification number.  Identify each individual photograph with a unique identification number and/or file name. If agency-specific naming conventions are used, documentation must be provided describing thesestandards.
 

5.4.2.2   Caption.  Provide narrative text describing each individual image in order to understand and retrieve it. Standard caption information typically includes the "who, what, when, where, why" about the photograph.
 

5.4.2.3   Photographer.  Identify the full name (and rank, if military) and organization (agency, if Federal) of the photographer credited with the photograph, if available.
 

5.4.2.4   Copyright.  Indicate for each image whether there is a restriction on the use of that image because of a copyright or other property rights. Agencies must provide, if applicable, the owner of the copyright and any conditions on the use of the photograph(s), such as starting and ending dates of the restriction.
 

5.4.3   Agencies also must provide technical information about the records (i.e., metadata). NARA prefers that this information be captured for each image in the image header, but will accept transfers of records with this information in the accompanying documentation. Specific information required includes, but is not limited to:
 

 

5.4.3.1  File format.  List the file format and version (if applicable) of each image file transferred to NARA.

5.4.3.2   Bit depth.  Identify the bit depth of the transferred files according to the provisions of sections 5.3.1 and 5.3.2.

5.4.3.3   Image size.  Specify the image height and width of each image in pixels according to the provisions of sections 5.3.3 and 5.3.4.

5.4.4  For digital photographs created after January 1, 2005, agencies must supply the following additional technical information, preferably as part of each image's header. Agencies currently capturing this information must provide it with the above-cited documentation.

 

5.4.4.1   Image source.  Identify the original medium used to capture the images (i.e., the make and model of the digital camera or the make and type of the film used).

5.4.4.2   Compression.  Identify the file compression method used (if applicable) and the compression level (e.g., medium, high) selected for the image(s).

5.4.4.3   ICC/ICM profile. ¹⁸  Provide custom or generic color profiles, if available, for the digital camera or scanner used [e.g., sRGB (standard Red Green Blue)].

5.4.4.4   EXIF information. ¹⁹  If available, preserve and transfer to NARA the Exchangeable Image File Format (EXIF) information embedded in the header of image files (as TIFF tags or JPEG markers) by certain digital cameras (e.g., make and model of the digital camera).

5.4.5   Agencies must provide all external finding aids for the transferred digital photographic records in formats approved by NARA with the appropriate documentation required by 36 CFR 1228.266(e) and 1228.270(d). Finding aids include database files, thumbnail indexes, shelf lists, caption cards, and other documentation necessary or helpful in properly identifying, retrieving, and using the records.

5.4.6   For scanned images of photographs, agencies must supply a description of the quality control inspection process, and a report on the results of the last inspection performed on the records and the date of that inspection. As part of the report, agencies should visually inspect a sample of the images for defects, evaluate the accuracy of finding aid data, verify file header information and file name integrity, and completeness of the images in the transfer.

 

5.4.6.1   For inspections conducted after the effective date of this guidance, agencies must use one of the quality sampling methods presented in ANSI/AIIM, Sampling Procedures for Inspection by Attributes of Images in Electronic Image Management and Micrographic Systems (ANSI/AIIM TR34-1996). ²⁰

6.0   TRANSFER MECHANISMS

6.1   Agencies may transfer digital photographic records using any of the approved media or methods listed in 36 CFR 1228.270(c). ²¹

6.2   Digital photographic records must not be compressed (e.g., Winzip, PKZIP) or aggregated (e.g., TAR) for purposes of transfer unless NARA has approved the transfer in compressed or aggregated form in advance. In such cases, NARA may require the agency to provide the software to decompress the records [see 36 CFR 1228.270(d)].

7.0   LEVELS OF ACCESS

NARA will provide access to the creating agency and to all researchers requesting digital photographic records accessioned from Federal agencies, subject to review of content for FOIA exemptions as is feasible. While compliance with these requirements will improve future access to accessioned digital photographic records, NARA's ability to provide access to certain records will vary according to their hardware and software dependencies. At the present time, NARA provides users with a copy of fully releasable electronic record files on any of the media currently approved by NARA. For digital photographic records transferred to NARA, the user will be responsible for obtaining the necessary hardware and software to view the records.

8.0   CONTACT INFORMATION

For assistance in scheduling digital photographic records, or to discuss how to handle permanent digital photographic records that do not meet the specifications in section 3.0, please contact your agency appraisal archivist in the Life Cycle Management Division (NWML). The NWML general telephone number is 301-837-3560.

For assistance in transferring digital photographic records to NARA, please contact the Electronic and Special Media Records Services Division (NWME), 8601 Adelphi Road, College Park, MD 20740. The general telephone number is 301-837-3420.

¹ Hereafter the terms "photographs" and "digital photographic records" will be used to describe digital camera files and scans of photographic prints, slides, and negatives.

² Megapixel is millions of pixels, which is a measurement calculated by multiplying the pixel array values for image width (in pixels) by image height (in pixels).

³ In the 'II' format (i.e., little-endian), byte order is always from the least significant byte to the most significant byte.

⁴ For records created after the effective date of this guidance, TIFF version 6.0 is recommended and preferred. Versions 4.0 and 5.0 are acceptable. The reference specifications for version 6.0 are defined at http://partners.adobe.com/public/developer/tiff/index.html#spec.

⁵ The acronym JPEG stands for the Joint Photographic Experts Group, a standards committee formed in 1982 by the International Standards Organization (ISO) to research methods for electronically transmitting video, still images, and text.

⁶ Height and width of an image in pixels.

⁷ The proportion of an image's size given in terms of the horizontal dimension versus the vertical dimension.

⁸ 2000 line files describe digital photographs that are 2000 pixels across the long dimension of the image

.

⁹ DPI denotes dots per inch, a measure of the resolution of electronic images, which is the term most commonly used in available hardware and software, and is most widely recognized and understood by the community.

¹⁰ 3000 line files describe digital photographs that are 3000 pixels across the long dimension of the image.

¹¹ True optical resolution is defined as the maximum or actual resolution of a device without recourse to interpolation. Interpolation (see note 12) that occurs as part of the normal operation of digital cameras is acceptable.

¹² The process of calculating greater or fewer pixels from existing pixels in order to resize an image as either larger or smaller.

¹³ Lossless refers to a method of image compression where there is no loss in quality when the image is compressed or uncompressed.

¹⁴ Lossy refers to a method of image compression where some image content is sacrificed in exchange for higher compression ratios.

¹⁵ While there is no standard or industry-recognized metric for determining medium quality, records created using this setting would reveal some degradation of the image without substantive loss of quality when viewed at normal size.

¹⁶ While there is no standard or industry-recognized metric for determining high quality, records created using this setting would reveal no noticeable loss of quality or image degradation when viewed at normal size.

¹⁷ Examples of descriptive metadata elements include Dublin Core and International Press Telecommunications Council (IPTC) metadata.

¹⁸ The International Color Consortium (ICC) and Microsoft Windows Image Color Management (ICM) profiles define industry standard methods of generating and interpreting numeric values that describe color for digital screens, scanners, and output devices to ensure color consistency across platforms and devices.

¹⁹ Detailed technical information on the EXIF standard can be found at http://www.exif.org.

²⁰ AIIM standards may be obtained from the Association of Information and Image Management, 1100 Wayne Avenue, Suite 1100, Silver Spring, MD 20910. The standards can be ordered online at http://www.aiim.org/.

²¹ http://www.archives.gov/about/regulations/regulations.html