TIFF and GIF files may contain more than one image. The
FrameCount property reflects the number of images found in the
file. You can select different images using the Frame property.
Multi-frame TIFF images are generally used for one of two
purposes. Sometimes, multiple copies of the same image are embedded
at different sizes to allow previews to be obtained quickly and
easily. This type of multi-frame image is generally created for
print purposes. Sometimes, multiple pages of a document may be
embedded in a TIFF. This type of multi-frame image is generally
created by document scanning software or fax software.
Multi-frame GIF images are often called animated GIFs. Each
image represents a frame of the animation.
PostScript is a programming language. So a PostScript program
may output a different number of pages each time it is run. For
this reason, it is not possible to reliably determine the number of
pages in a PostScript file until it is actually displayed. As a
result, EPS and PS files always have a FrameCount of one no matter
how many pages they may display. However, it is reasonably safe to
assume that EPS files only ever contain one page of content.