Sustainability of Digital Formats: Planning for Library of Congress Collections |
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Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact |
Full name | ISO/IEC 10918-1:1994. Information technology -- Digital compression and coding of continuous-tone still images, lossless (formal name); Original lossless JPEG (common name) |
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Description |
Lossless compression encoding for full color and grayscale continuous-tone images. Annex H of the standard states that "The processes which provide for sequential lossless encoding and decoding are not based on the DCT [discrete cosine transform]. The processes are spatial processes based on the coding model for the DC coefficients of the DCT." The coding models may employ either Huffman or arithmetic coding. Many commentators, including the JPEG committee, report that these ISO/IEC 10918-1 lossless compression methods were never supported in applications and they were soon supplanted by JPEG-LS, specified in ISO/IEC 14495-1 and -2 (1999 and 2003, Lossless and near-lossless, baseline and extensions). One of the Huffman-encoded variants of original lossless, however, is used by Adobe's DNG_1_1. According to the specifications, the other file formats listed in this description's Relationships may contain JPEG-LS data; however, the compiler is not aware of the existence of such files in actual practice; Comments welcome. |
Production phase | May be applied in initial-state picture creation; often used for middle- and final-state archiving or end-user delivery. |
Relationship to other formats | |
Subtype of | JPEG, JPEG Image Encoding Family |
Used by | DNG_1_1, Adobe Digital Negative (DNG), Version 1.1 |
Used by | Canon CR2 format and several Kodak raw formats, not described at this Web site. |
Used by | JFIF_Family, JPEG File Interchange Format Family |
Used by | JFIF_1_02, JFIF JPEG File Interchange Format, Version 1.02 |
Used by | JFIF File Interchange Format, Versions 1.00 and 1.01, not described at this Web site at this time |
Used by | SPIFF, SPIFF Still Picture Interchange File Format |
Used by | DNG_1_6, Adobe Digital Negative (DNG), Version 1.6 |
LC experience or existing holdings | See JPEG |
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LC preference | See JPEG |
Disclosure | Fully disclosed. Developed by the Joint Photographic Experts Group (JPEG), formally known as ISO/IEC JTC 1/SC 29/WG 10. |
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Documentation | ISO/IEC 10918-1:1994, Information technology -- Digital compression and coding of continuous-tone still images: Requirements and guidelines. Same as ITU-T Rec. T.81:1992. |
Adoption | No adoption as an image format on its own. The compression method, however, is employed when raw camera data is converted to Adobe's DNG_1_1 format. |
Licensing and patents | See JPEG. |
Transparency | Depends upon algorithms and tools to read; will require sophistication to build tools. |
Self-documentation | Not investigated for this format description. |
External dependencies | None. |
Technical protection considerations | None. |
Still Image | |
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Normal rendering | Lack of adoption, low levels of support. |
Clarity (high image resolution) | Should be very good, but source data is limited to 8-bits-per-channel. Lack of adoption may render this moot. |
Color maintenance | Not investigated for this format description. |
Support for vector graphics, including graphic effects and typography | No support for vector graphics. |
Support for multispectral bands | See JPEG. |
Functionality beyond normal rendering | Not investigated for this format description. |
Tag | Value | Note |
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Filename extension | Not applicable. | See JFIF_1_02, SPIFF, and JPEG_EXIF. |
Internet Media Type | Not applicable. | See JFIF_1_02, SPIFF, and JPEG_EXIF. |
Magic numbers | Hex: 0xFF 0xD8 |
Start of Image (SOI) marker; see also JPEG |
Indicator for profile, level, version, etc. | Hex: 0xFFC3 |
Start of Frame (SOF) marker for Huffman lossless (sequential); see also JPEG |
Indicator for profile, level, version, etc. | Hex: 0xFFC7 |
Start of Frame (SOF) marker for Huffman differential lossless (sequential); see also JPEG |
Indicator for profile, level, version, etc. | Hex: 0xFFCB |
Start of Frame (SOF) marker for arithmetic lossless (sequential); see also JPEG |
Indicator for profile, level, version, etc. | Hex: 0xFFCF |
Start of Frame (SOF) marker for arithmetic differential lossless (sequential); see also JPEG |
General | |
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History |
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