Distortion problem of point cloud map

[APPZ99]

Hi, thanks for your great work!

I encountered some problems when converting the depth map to a point cloud. I used Depth anything to predict the depth of images from the KITTI360 dataset, and when I tried to convert it to a point cloud, I found that it confused me in some details.

The predicted image and its depth map are shown below:

The converted point cloud is shown below:

From the top view, we can see that the road is funnel-shaped, and the road signs also show that they are seriously distorted. The point cloud as a whole shows a distortion that converges towards the center of the camera.

I would like to ask what is the cause of these problems? Maybe the depth map is too dense? Or is it a problem with my camera model? Below is the conversion code I used (pinhole camera model).

image_path = './conver_100.png'

depth_image = Image.open(image_path).convert("I")
depth_np = np.asarray(depth_image, dtype=np.uint16)
depth_np = (depth_np - np.min(depth_np)) / (np.max(depth_np) - np.min(depth_np))

def depth_to_point_cloud(depth_map, intrinsic):
    h, w = depth_map.shape
    i, j = np.meshgrid(np.arange(w), np.arange(h), indexing='xy')

    x = (i - intrinsic[0, 2]) * depth_map / intrinsic[0, 0]
    y = (j - intrinsic[1, 2]) * depth_map / intrinsic[1, 1]
    x = x.reshape(-1)
    y = y.reshape(-1)
    z = depth_map.reshape(-1)

    points = np.stack((x, y, z), axis=-1)
    return points

def visualize_point_cloud(points):
    pcd = o3d.geometry.PointCloud()
    pcd.points = o3d.utility.Vector3dVector(points)
    o3d.visualization.draw_geometries([pcd])

fx = 552.554261  
fy = 552.554261 
cx = 682.049453  
cy = 238.769549  

intrinsic = np.array([
    [fx, 0, cx],
    [0, fy, cy],
    [0, 0, 1]
])

points = depth_to_point_cloud(depth_np, intrinsic)
visualize_point_cloud(points)

The point cloud below is what I got with the same code after getting the depth map from the LiDAR point cloud. It can be seen that its geometric performance is relatively good, without obvious distortion

[dsfcdsfdg]

I have the same question. Did you solve this distortion?