SPIFF
From Just Solve the File Format Problem
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'''Still Picture Interchange File Format''' ('''SPIFF''') is an image file format based on the [[JPEG]] interchange format. It supports both lossy and lossless compression. It is not widely used. | '''Still Picture Interchange File Format''' ('''SPIFF''') is an image file format based on the [[JPEG]] interchange format. It supports both lossy and lossless compression. It is not widely used. | ||
| − | It overlaps the JPEG standard. Some SPIFF files are valid JPEG files, and | + | It overlaps the JPEG standard. Some SPIFF files are valid JPEG files, and those that are will most likely be displayed correctly by a typical JPEG/[[JFIF]] viewer, even if it knows nothing about SPIFF. |
It also supports additional image types and compression schemes that are incompatible with JPEG. | It also supports additional image types and compression schemes that are incompatible with JPEG. | ||
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* 3 = Rec T.6 MMR ([[CCITT Group 4]]) | * 3 = Rec T.6 MMR ([[CCITT Group 4]]) | ||
* 4 = [[JBIG]] | * 4 = [[JBIG]] | ||
| − | * 5 = [[JPEG]] | + | * 5 = [[JPEG]] (restricted to a few widely-supported varieties) |
* 6 = [[JPEG-LS]] | * 6 = [[JPEG-LS]] | ||
| + | |||
| + | == Identification == | ||
| + | A SPIFF file that uses JPEG compression should use file extension '''.jpg'''; otherwise '''.spf'''. | ||
| + | |||
| + | Valid SPIFF files begin with <code>FF D8 FF E8 ?? ?? 'S' 'P' 'I' 'F' 'F' 00</code>. | ||
== Specifications == | == Specifications == | ||
Revision as of 18:42, 3 March 2013
Contents |
Overview
Still Picture Interchange File Format (SPIFF) is an image file format based on the JPEG interchange format. It supports both lossy and lossless compression. It is not widely used.
It overlaps the JPEG standard. Some SPIFF files are valid JPEG files, and those that are will most likely be displayed correctly by a typical JPEG/JFIF viewer, even if it knows nothing about SPIFF.
It also supports additional image types and compression schemes that are incompatible with JPEG.
Format
SPIFF files contain a JPEG APP8 segment, with an identifier of "SPIFF".
Compression schemes
- 0 = Uncompressed
- 1 = Rec T.4 MH (1-dimensional CCITT Group 3)
- 2 = Rec T.4 MR (2-dimensional CCITT Group 3)
- 3 = Rec T.6 MMR (CCITT Group 4)
- 4 = JBIG
- 5 = JPEG (restricted to a few widely-supported varieties)
- 6 = JPEG-LS
Identification
A SPIFF file that uses JPEG compression should use file extension .jpg; otherwise .spf.
Valid SPIFF files begin with FF D8 FF E8 ?? ?? 'S' 'P' 'I' 'F' 'F' 00.
Specifications
- ITU-T Rec. T.84 Annex F
- ITU-T Rec. T.86 - Includes information about registration of SPIFF extensions
- ITU-T Rec. T.87 - Defines compression type 6 (JPEG-LS)
