Examples 2. Modifying an Existing Raster Image

This example illustrates the use of the routines GRselect/mgselct to obtain
an existing raster image and GRwrite/mgwrimg to modify image data.

In this example, the program selects the only raster image in
the file "General_RImages.hdf" created and written in Example 1,
and modifies image data.
The program also creates another raster image that is named
"Image Array 2" and has 3 components with dimension size of 4x6, DFNT_CHAR8
data type, and MFGR_INTERLACE_PIXEL interlace mode.