An apparatus for determining the volume of a liquid in a container. A digital camera is provided to view the container. A processor can optically detect certain characteristics of the container as viewed by the camera and accesses a computer memory having stored characteristics of a plurality of known containers, and the compare the detected certain characteristics with the stored characteristics to identify the container from the plurality of known containers. The processor can calculate the volume of the container as a function of the distance between the first and second ends of the container as viewed by the camera. The processor can receive at least one image from the camera and determine whether the liquid in the container contains any air pockets based on the at least one image. Methods are provided, including a method for use by an apparatus having a camera and a processor electrically coupled to the camera to confirm the dosage of a medicament in a container.