# Around-View-Monitoring-Based Automatic Parking System Using Parking Line Detection
## 1 Introduction  
Recently, as the number of vehicles has increased, the automobile industry has expanded its research and development; for instance, driver assistance systems are being studied intensively. Driver assistance systems consist of lane departure warning, forward collision warning, pedestrian protection, and parking assist systems [1, 2]. The parking assist system assists the driver in parking situations so that they can park easily. These systems have continuously increased in sophistication from collision warning systems using an ultrasonic sensor [3, 4] to systems that show a rear image to the driver using a rear camera, systems that provide a 360\({}^{\circ}\)-view using an around view monitoring (AVM) camera [5, 6, 7], and fully automatic parking systems [5].  
This paper presents an automatic parking system that uses AVM images in a driver assistance system. An AVM system consists of cameras on the front, rear, left, and right sides of the vehicle and shows a 360\({}^{\circ}\)-camera view of the vehicle's environment. In particular, it shows the driver a synthesized image of the top view of the vehicle. Because the AVM system provides a top view, it can be used for various applications involving image recognition such as lane detection, moving object detection, and parking line detection. These systems can use the original images from the cameras, but such an approach requires extensive computation time because four images must be processed. By contrast, if a synthesized top view image is used, the processing time of only one image is required. Therefore, in this paper, we propose an automatic parking method that detects parking lines and performs parking control using a top view image.  
Parking line recognition is an important process in an automatic parking system. Using the detected parking lines, a system can be configured to automatically park the car in the area desired by the driver. When parking lines are detected in the top view AVM image, the position of each pixel can be converted into a distance, which is advantageous for automatic parking. In addition, all parking lines in each direction can be detected.  
The detected parking lines provide relative coordinates because it is easy to convert pixels into distances from the vehicle. Hence, we use these relative coordinates to set a goal to the desired parking location and perform automatic parking using path planning and tracking methods.  
Figure 1 presents an overview of the proposed method.  
As shown in the figure, when an AVM image is input to the system, the parking lines are detected. The proposed system determines the parking area from the detected parking lines. It also determines the relative location of the car to the parking area and the shape of the parking area. Path planning is performed using this information, and automatic parking is performed through path tracking.  
The rest of this paper is organized as follows. Related studies on the detection of parking areas and automatic parking control are summarized in Section 2. Section 3 presents the proposed method. Section 4 presents the experimental results, and the paper is concluded in Section 5.