在已知相机距地面高度的前提下，通过水平拍摄照片，计算某一物体距离照相机的距离。 通过计算机编程实现点的选取、坐标确定以及距离精确计算。-In the known camera height the ground under the premise of taking pictures by level, to calculate the distance of an object the camera. Select achieve points through computer p