CALL IMG_IN1( 'SPECTRUM', NX, IP, ISTAT ) CALL IMG_IN2( 'IMAGE', NX, NY, IP, ISTAT ) CALL IMG_IN3( 'CUBE', NX, NY, NZ, IP, ISTAT )Note how the number of dimensions is specified by appending a number to the routine name, and how IMG_IN2 is just a synonym for IMG_IN (2 dimensions are assumed if you do not say otherwise).
As well as accessing input images, there are equivalent routines for performing most other IMG operations on images with between 1 and 3 dimensions. For instance, the following would create a new 3-dimensional image:
CALL IMG_NEW3( 'CUBE', NX, NY, NZ, IP, ISTAT )
When accessing an existing image with (say) 2 dimensions, you will also be able to access an appropriate slice from (say) a 3-dimensional image if you specify this when you are prompted for the image name (see elsewhere).
IMG Simple Image Data Access