Ran to it in my textbook. Is it Figure 1 hyphen 4 Could you explain more about how the numbers below pictures are usually stated and read?
There are likely two ways you can refer to a figure number such as this one.
The more "proper" way might be to say "figure one dash four." This would be the better way to state it if your listener does not have a copy of the text in front of him because he cannot visualize where the hyphen is placed.
But the more "colloquial" (and thus more understandable and desirable) way might be simply "figure one four." No one will confuse "one four" as being the same as "14" so you should not worry about that. This way works where the listener is looking at the figure numbers with you because he will see the hyphen—i.e. he will know by context that "one four" is referring to the "1-4" he sees beneath the picture, even though you did not specify the location of the hyphen.
I believe you will encounter more instances where someone simply says "figure one four" instead of "figure one dash four," but it depends on one's personal taste and whether the listener has the ability to determine where the hyphen is placed without being told its location (as explained above).
Lastly, to say "figure one hyphen four" would almost never sound natural. Do not say "hyphen." Say "dash" if you want to convey the idea of the hyphen, except in rare circumstances.