Pixel-level alignment algorithm for color images to depth images of color depth camera

The invention discloses a pixel-level alignment algorithm for color images to depth images of a color depth camera. The pixel-level alignment algorithm comprises the steps of 1) determining an offset between an infrared image and a depth image, 2) calibrating the internal parameters of an infrared camera and a color camera, respectively, 3) calibrating relative postures between the infrared camera and the color camera, 4) calibrating the parameters of a depth camera model, 5) starting from one pixel point of the color image, finding out corresponding pixel points on the depth image by use of the internal and external parameters of an infrared image and a color image, thereby determining the depth of the pixel points of the color image. According to the pixel-level alignment algorithm, the corresponding depth information is directly obtained from the color image, the alignment of the color information to the depth information can be realized, a fusion image of a larger size can be obtained, and the information is richer.