MIL-STD-2301 Computer Graphics Metafile Cgm Implementation Standard For The National Imagery Transmission Format StandardThis standard establishes the requirements necessary to implement Computer Graphics Metafiles CGM used for the representation of symbol graphics in the National Imagery Transmission Format Standard NITFS.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 - 47 - 48 - 49 - 50 - 51 - 52 - 53 - 54 - 55 - 56 - 57 - 58 - 59 - 60 - 61 - 62 - 63 - 64 - 65 - 66 - 67 - 68 - 69 - 70 - 71 - 72 - 73 - 74 - 75 - 76

MIL-STD-2301A

5.2.2.1.38  Default colors for unsupported text.  The CGM implementation for NITFS shall  substitute available system colors for unsupported colors specified in the Text Color element, Fill Color element, Edge Color element, and the Line Color element.

5.2.2.1.39  CGM element substitution.  The CGM implementation for NITFS shall report or substitute for any CGM element and associated parameters not supported in the CGM implementation for NITFS and continue

to interpret the next element supported in the CGM implementation for the NITFS.

5.2.2.1.40  CGM error messages.  The CGM implementation for NITFS should report errors encountered during the input and interpretation of the CGM.

5.2.2.2  CGM element functional output requirements.

5.2.2.2.1  CGM output required elements.  The following CGM elements are required for each CGM that the CGM implementation for NITFS generates and outputs:

a.  Begin Metafile

b.  Metafile Version

c.  Metafile Element List d.  Metafile Description e.  Begin Picture

f.  Color Selection Mode g.  VDC Extent

h.  Begin Picture Body i.  End Picture

J.  End Metafile

5.2.2.2.2  Metafile Description element contents required for output.  The CGM implementation for

NITFS shall generate and output the Metafile Description element that contains the following substring: NITF/CGM-APP-2.0 for CGM placed in NITF2.0 and/or NITF 2.1 files.

And additionally, for NITF 2.1 files only:

NITF/CGM;ProfileEd:2301-2/Source:producer;Date:YYYYMMDD

Where 'producer' is the application name and release/version of the application producing or modifying the

CGM.  The date shall reflect the creation date or more recent date of modification.

5.2.2.2.3  Length of parameter strings required for output for the Begin Metafile, Begin Picture, and Metafile Description elements.  The CGM implementation for NITFS shall generate and output the Begin Metafile, Begin Picture, and Metafile Description elements with parameter strings not to exceed 1024 characters.

5.2.2.2.4  Length of parameter strings required for output for the Font List element. The CGM

implementation for NITFS shall generate and output the Font List element with parameter strings not to exceed

1024 characters.

5.2.2.2.5  Number of Begin Picture elements and Begin Picture Body elements required for output.  The CGM implementation for NITFS shall generate and output only one Begin Picture element with only on Begin Picture Body element.

48