In order to support various safety services, a vehicle needs to observe surroundings thereof. To this end, the vehicle includes a surrounding observing device. For example, the vehicle includes a lidar sensor. The lidar sensor transmits a signal toward a front direction or the like and analyzes a feedback signal, thereby generating a video image. During this process, the lidar sensor divides upper and lower sides of the front thereof into predetermined layers and obtains the video image for each layer. That is, the lidar sensor according to the related art supports a multi-layer image.
However, since the image generated based on the multi-layer has a significant amount of data distribution to be determined to support a specific service, it has several problems. Therefore, it is necessary to converge the same object among objects for each multi-layer. In order to solve this problem, according to the related art, the image has been processed based on a state in which the objects for each layer are overlapped. However, in the case in which the image is simply processed based on the overlapped state, it is impossible to finely distinguish between the objects. This may potentially make a risk prediction of the vehicle or avoidance difficult.