Count the number of frames in a TIFF file.Source:
TIFF files can hold many frames. Often this is sensible, e.g. each frame could be a time-point in a video or a slice of a z-stack.
A number, the number of frames in the TIFF file. This has an
n_dirs which holds the true number of directories in the TIFF
file, making no allowance for the way ImageJ may write TIFF files.
For those familiar with TIFF files, this function counts the number of directories in a TIFF file. There is an adjustment made for some ImageJ-written TIFF files.
count_frames(system.file("img", "Rlogo.tif", package = "ijtiff")) #>  1 #> attr(,"n_dirs") #>  1