Obstacle avoidance projection method and projection system

An obstacle avoidance projection method executed by a mobile device, wherein the mobile device comprises a camera unit and a processing unit coupled to the camera unit, the mobile device is communicatively connected to a projection device, and the obstacle avoidance projection method comprises steps of:

• capturing a first reference image by the camera unit, wherein the first reference image comprises a first calibration image projected by the projection device onto a projection surface, and the first calibration image comprises a calibration pattern;
• capturing a second reference image by the camera unit, wherein the second reference image comprises a second calibration image projected by the projection device onto the projection surface, and the second calibration image is a background color image;
• and
• executing steps as follows by the processing unit:
• receiving first reference image information corresponding to the first reference image and second reference image information corresponding to the second reference image from the camera unit, and obtaining first calibration image information corresponding to the first calibration image;
• calculating a plurality of matching image feature point pairs based on the first reference image information and the first calibration image information;
• based on the plurality of matching image feature point pairs, performing mapping transformation on region information corresponding to the first calibration image in the second reference image information to generate obstacle avoidance image information;
• performing an edge detection operation on the obstacle avoidance image information to generate edge detection result image information corresponding to an edge detection result image;
• performing a region determination operation on the edge detection result image information to set a maximum obstacle-free region in the edge detection result image;
• and
• generating a plurality of projection range coordinates based on the maximum obstacle-free region, and sending the plurality of projection range coordinates to the projection device.