An image set is an object that identifies the location of an image. The image is typically a large image to be broken down into sub-images. The sub-images must all have the same size and be positioned side by side.
The following functions are available to create image set objects:
make-general-image-set
make-icon-resource-image-set
make-scaled-image-set
make-scaled-general-image-set
make-resource-image-set
image-list, image-set and image-locator
Adding Toolbars
CAPI User Guide and Reference Manual (Windows version) - 3 Aug 2017