1. An integrated image surveillance system, essentially comprising: a first camera for capturing a first image of an area, wherein the first image is a static, large-coverage image of the area; a second camera for capturing a second image of the area, wherein the second image is a dynamic, small-coverage image of the area, and the second image and the first image have a first overlap region; an image processing device, essentially comprising: a first defining component, configured to define first set of feature points in the first image and second set of feature points in the second image, wherein the first set of feature points and the second set of feature points have a first registration relation, and the first registration relation further defines a first registration function for the first image and the second image; a first synthesis component, configured to integrate the first image and the second image according to the first registration function so as to form a third image, wherein, upon overlapping of the first image and the second image, data of the second image are shown in the third image; and an adjusting component, configured to adjust discontinuous image chromaticity in the third image on two sides of a seam between the first image and the second image; and a display device for displaying the third image.