This research presents a technique for counting the number of people in a smart office room when walking in and out of the door by relying on a normal quality webcam. This means that the camera is not high resolution. The picture is not clear and sharp. Therefore, the image must be counted to adjust the color first before being processed in other steps. The designed system uses OpenCV and Raspberry Pi to help and is Edge Computing processing by comparing images in front view and top view. The front view is accurate at 58.44% for entering the room and 30.15% accurate for leaving the room. However, it was clear that the top view image would be more accurate at 87.82% for walking into the room and 80.75% out of 130 tests for walking out of the room. This system can also be used for counting people in other situations, such as counting people in factories, counting workers on the job site and counting people at trade fairs, etc.