CALS raster
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== Overview == | == Overview == | ||
| − | '''CALS raster''' is a group of image file formats | + | '''CALS raster''' is a group of image file formats developed by the U.S. Department of Defense as part of the '''CALS''' initiative. |
CALS stands for '''Continuous Acquisition and Life-cycle Support''' (new name), or '''Computer Aided Acquisition and Logistics Support''' (old name). | CALS stands for '''Continuous Acquisition and Life-cycle Support''' (new name), or '''Computer Aided Acquisition and Logistics Support''' (old name). | ||
== Format == | == Format == | ||
| − | There are two main formats, and | + | There are two main formats, Type 1 and Type 2, and two more that have also been placed under the CALS umbrella. |
=== Type 1 === | === Type 1 === | ||
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=== Type 2 === | === Type 2 === | ||
| − | * Description: Office Document Architecture (ODA) Raster Document | + | * Description: Office Document Architecture (ODA) Raster Document Application Profile (DAP) |
* Filename extension: .ct2 | * Filename extension: .ct2 | ||
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== Resources == | == Resources == | ||
| + | * [http://www.dtic.mil/dtic/tr/fulltext/u2/a261244.pdf Tiled Raster Graphics and MIL-R-28002A: A Tutorial and Implementation Guide] (Type 1 and 2) | ||
* [http://www.fileformat.info/format/cals/egff.htm CALS Raster File Format Summary] | * [http://www.fileformat.info/format/cals/egff.htm CALS Raster File Format Summary] | ||
* [[Wikipedia:CALS Raster file format|Wikipedia article]] | * [[Wikipedia:CALS Raster file format|Wikipedia article]] | ||
Revision as of 20:11, 11 April 2013
Contents |
Overview
CALS raster is a group of image file formats developed by the U.S. Department of Defense as part of the CALS initiative.
CALS stands for Continuous Acquisition and Life-cycle Support (new name), or Computer Aided Acquisition and Logistics Support (old name).
Format
There are two main formats, Type 1 and Type 2, and two more that have also been placed under the CALS umbrella.
Type 1
- Filename extension: .ct1 (MIL-PRF-28002C), .cal (MIL-PRF-28002B)
Type 1 files have a 2048-byte ASCII header, consisting of up to 16 128-byte header fields.
Bi-level image data follows, which always uses CCITT Group 4 compression.
There are two versions of Type 1 format: one defined in MIL-PRF-28002B, and one defined in MIL-PRF-28002C.
Type 2
- Description: Office Document Architecture (ODA) Raster Document Application Profile (DAP)
- Filename extension: .ct2
Type 2 is a more complex format, which adds support for multiple images, uncompressed images, and other things.
Type 3
- Filename extension: .ct3, .nif
- Description: Navy Image File Format (NIFF)
Type 4
- Description: JEDMICS C4
- Filename extension: .ct4, .c4
Refer to JEDMICS C4.
Identification
Type 1 files most likely begin with ASCII string "srcdocid:", "rorient:", or "version: MIL-STD-1840".
Type 3 files begin with signature bytes 49 49 4E 31 (ASCII "IIN1").
Specifications
- MIL-PRF-28002C: CALS raster; defines Type 1, 3, and 4.
- FIPS PUB 194: Type 2
- MIL-STD-1840C: CALS
