The present disclosure relates to a three dimensional (3D) scanning apparatus. The 3D scanning apparatus includes an image sensor and a processor. The image sensor has a first sensing area and a second sensing area. The first sensing area is configured to capture a first set of images of an object. The second sensing area is configured to capture a second set of images of the object. The processor is configured to establish a first model based on the first set of images and to establish a second model based on the second set of images. The processor is further configured to compare a correspondence between the first model and the second model.