1. A method comprising: receiving depth information of a target object acquired by an image capturing system; determining real-time three-dimensional information of the target object in a predetermined inspecting area based on the depth information of at least one real-time image of the target object; determining a position and/or orientation of the target object relative to at least one color camera of a color camera system based on the depth information of the at least one real-time image of the target object and position information of the at least one color camera of the color camera system relative to at least one image capturing camera of the image capturing system, wherein the position information of the at least one color camera of the color camera system relative to the at least one image capturing camera of the image capturing system is fixed and predetermined; and projecting color pixel information of a real-time color image of the target object onto a three-dimensional virtual model based on the determined position and/or orientation of the target object relative to the at least one color camera of the color camera system to generate a color three-dimensional virtual model comprising the color pixel information, wherein the color pixel information is based on the real-time three-dimensional information of the target object and the real-time color image of the target object acquired by the color camera system.