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6.6 8-Bit Raster Image Information Retrieval Routines

6.6.1 Querying the Total Number of 8-Bit Raster Images: DFR8nimages

DFR8nimages returns the total number of 8-bit raster image sets in a file and has the following syntax:

C:		num_of_images = DFR8nimages(filename);
FORTRAN:	num_of_images = d8nimg(filename)

TABLE 6I - DFR8nimages Parameter List

Routine Name

[Return Type]

(FORTRAN-77)
Parameter
Parameter Type
Description
C
FORTRAN-77
DFR8nimages

[intn]

(d8nims)
filename
char *
character*(*)
Name of the HDF file.

6.6.2 Determining the Reference Number of the Most-Recently-Accessed 8-Bit Raster Image: DFR8lastref

DFR8lastref returns the reference number most recently used in writing or reading an 8-bit raster image. This routine is primarily used for attaching annotations to images and adding images to vgroups. (See Chapters 8, titled Annotations (DFAN API) and Chapter 5, titled Vgroups (V API) for more detailed information on how to use reference numbers in connection with these applications.)

The following calling sequence uses DFR8lastref to find the reference number of the 8-bit raster image most recently added to an HDF file:

C:		status = DFR8addimage(filename, image, width, height, compress);
		lastref = DFR8lastref( );
FORTRAN:	status = d8aimg(filename, image, width, height, compress)
		lastref = d8lref( )
DFR8putimage or DFR8getimage can be used instead of DFR8addimage with similar results.

6.6.3 Determining the Reference Number of the Palette of the Most-Recently-Accessed 8-Bit Raster Image: DFR8getpalref

DFR8getpalref returns the reference number of the palette associated with the most recently used in writing or reading an 8-bit raster image. The DFR8getdims routine must be called before DFR8getpalref, as DFR8getdims initializes internal structures required by DFR8getpalref.

There is currently no FORTRAN-77 version of the DFR8getpalref routine.

TABLE 6J - DFR8nimages Parameter List

Routine Name

[Return Type]

Parameter
Parameter Type
Description
C
DFR8getpalref

[intn]

pal_ref
uint16 *
Pointer to the returned reference number of the palette.



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HDF User's Guide - 07/21/98, NCSA HDF Development Group.