The invention provides an image processing apparatus for generating coordination calibration points. The image processing apparatus includes a subtracting module, an edge detection module and an intersection point generation module. The subtracting module subtracts a first image from a second image to generate a first subtracted image, and subtracts the first image from a third image to generate a second subtracted image. The edge detection module performs an edge detection process for the first subtracted image to generate a first edge image, and performs the edge detection process for the second subtracted image to generate a second edge image, wherein the first edge image includes a first edge and the second edge image includes a second edge. The intersection point generation module generates, according to the first and second edges, an intersection point pixel, serving as the coordination calibration point corresponding to the first edge and the second edge.