1. An image based touch apparatus comprising: at least two region indicators, each of the at least two region indicators including a plurality of indication units and a touch sensor, wherein the indication units are configured to mark a touch surface; at least one image capturing apparatus capturing at least one image including the at least two region indicators; and a processing apparatus connected to the at least one image capturing apparatus to receive the at least one image, wherein the processing apparatus identifies the touch surface according to the indication units in the at least one image, when the touch sensor detects an operating object touches the touch surface, the indication units of the at least two region indicators generate a touch message, and the processing apparatus analyzes the touch message according to the at least one image and determines a position of the operating object on the touch surface according to the at least one image.