Projector automatic focusing system based on camera

The utility model discloses a projector automatic focusing system based on a camera. The projector automatic focusing system based on the camera comprises an embedded processing system, a camera module, an image processing module, a projection module, and a motor driving module. The projection module comprises a projection control system and a projector lens connected with the projection control system. The camera module, the image processing module, and the motor driving module are connected with the embedded processing system. The projector lens and an optical parameter module are connected with the embedded processing system through the projection control system. The camera module is used for photographing a projection screen. The image processing module is used for processing data acquired by the camera module to obtain the sum of gradients of projected images so as to further drive, by means of the motor driving module, the lens of the projector to adjust a focus.