I want to add text labels for each panel of an inserted picture (e.g. A B C). Each individual figure currently exists as pdf and jpg, but I want to join them together into a single pdf with each panel labeled. I have searched high and low to figure out how to make text sit atop the image and have gotten nowhere (other than to import the pdf and make a new document). The end product should look like the image below (taken from web). I have done this plenty of times in Word, etc., but I would like to further my transition to LaTeX.