filename	IN:	Name of the file
	width	OUT:	Width of the image
	height	OUT:	Height of the image
	interlace_mode	OUT:	File interlace mode of the image

	Purpose	Retrieves dimensions and interlace storage scheme of next image.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	DF24getdims retrieves the dimensions and interlace of the image. If the file is being opened for the first time, DF24getdims returns information about the first image in the file. If an image has already been read, DF24getdims finds the next image. In this way, images are read in the same order in which they were written to the file.
		If the dimensions and interlace of the image are known beforehand, there is no need to call DF24getdims. Simply allocate arrays with the proper dimensions for the image and invoke DF24getimage to read the images. If, however, you do not know the values of width and height, you must call DF24getdims to get them and then use them to determine the amount of memory to allocate for the image buffer.
		Successive calls to DF24getdims and DF24getimage retrieve all of the images in the file in the sequence in which they were written.
		The interlace mode codes are: 0 for pixel interlacing, 1 for scan-line interlacing and 2 for scan-plane interlacing.

	FORTRAN	integer function d2gdims(filename, width, height, interlace_mode)
		character*(*) filename
		integer width, height, interlace_mode