A new view point of knowledge-based visual measurement is proposed, which takes the traditional stereovision
as a kind of visual measurement based on cameras’ knowledge. The currently works on visual measurement are classed to different categories based on the different kinds of knowledge used. The visual measurement methods based on the object’s knowledge such as point, line, plane, and statistic characteristics are shortly introduced. Then the methods based on motion knowledge and environmental knowledge are discussed. The knowledge expression and acquirement for visual measurement are concisely commented. Finally, several potentially developmental topics that are valuable to be further investigated are suggested.