RELATED APPLICATIONS

This application hereby claims the benefits of priority to Chinese Application No. 202010082490.X filed on Feb. 7, 2020, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to systems and methods for constructing a panorama model based on point clouds acquired from different view angles, and more particularly, to systems and methods for constructing a three-dimensional (3D) panorama model by registering point clouds acquired from different view angles based on color information derived from the point clouds.

BACKGROUND

In the real estate market, when a person wants to buy or rent a property, he typically would ask to tour the property first in order to visually experience the layout and furnishing. House tours are often conducted in person, e.g., by the property owner or a real estate agent. While property tours are informative to the potential buyer/renter, it is also time consuming and inefficient. Recently, Virtual Reality (VR) technology has been applied to conduct these tours virtually. Videos, images, and point cloud data of the property are taken in advance. A 3D panorama model is rendered based on the point cloud data and/or the images. As a result, a visitor can remotely view the property without having to do it in person.

3D panorama view reconstructs a scene using VR technology based on panoramic images. A panorama merges multiple images taken by camera in 360-degree view angles, thus reconstructing an all-around interactive view of the scene. Similarly, a 3D panorama model merges point clouds acquired at various times and various view angles into a panoramic model. Before the panoramic rendering, the multiple point clouds have to be registered (known as “point cloud registration” or “scan matching”), a process of finding a spatial transformation that aligns two point clouds. The purpose of the transformation is to merge the various data sets into a worldly consistent model, so that they can be seamlessly merged together to render the panorama model.

A point cloud is a collection of points on the surface of an object scanned by the acquisition device. The point cloud contains information of the distribution of these points, such as their 3D coordinates, and features of the object surface. Point clouds acquired by certain point cloud acquisition devices may further include depth information and color information. Point cloud registration can benefit from using the redundancy of information available for each point. For example, the registration may see improved accuracy if the coordinates, elevation, and color information of the points are all used.

However, most of the acquisition devices, such as a Light Detection and Ranging (LiDAR) device, are mobile devices that move around during the acquisition. As a result, the acquired depth information and color information are not well aligned, thus cannot be used to synthesis accurate color data. Using the existing color information in the point clouds to aid the registration may adversely affect its accuracy.

Embodiments of the disclosure improve the existing point cloud registration systems and methods by deriving various information, such as color information, from the point clouds instead of using the acquired color information.

SUMMARY

In one aspect, a system for constructing a three-dimensional panorama model of an object is disclosed. An exemplary system includes a storage device configured to receive a plurality of point clouds each acquired at a different view angle. Each point cloud includes three-dimensional positions of a plurality of target points on a surface of the object. The system further includes at least one processor configured to determine elevation and normal at each target point in each point cloud and convert the elevation of each target point to color information. The at least one processor is further configured to register every two adjacent point clouds among the plurality of point clouds based on the three-dimensional positions, the normal, and the color information of the respective target points of the two adjacent point clouds. The at least one processor is also configured to render the three-dimensional panorama model based on the registered point clouds.

In another aspect, a computer-implemented method for constructing a three-dimensional panorama model of an object is disclosed. An exemplary method includes receiving a plurality of point clouds each acquired at a different view angle. Each point cloud includes three-dimensional positions of a plurality of target points on a surface of the object. The method further includes determining, by at least one processor, elevation and normal at each target point in each point cloud, and converting the elevation of each target point to color information. The method also includes registering, by the at least one processor, every two adjacent point clouds among the plurality of point clouds based on the three-dimensional positions, the normal, and the color information of the respective target points of the two adjacent point clouds. The method additionally includes rendering, by the at least one processor, the three-dimensional panorama model based on the registered point clouds.

In yet another aspect, a non-transitory computer-readable medium having stored thereon computer instructions is disclosed. The computer instructions, when executed by at least one processor, perform a method for constructing a three-dimensional panorama model of an object is disclosed. The exemplary method includes receiving a plurality of point clouds each acquired at a different view angle. Each point cloud includes three-dimensional positions of a plurality of target points on a surface of the object. The method further includes determining elevation and normal at each target point in each point cloud, and converting the elevation of each target point to color information. The method also includes registering every two adjacent point clouds among the plurality of point clouds based on the three-dimensional positions, the normal, and the color information of the respective target points of the two adjacent point clouds. The method additionally includes rendering the three-dimensional panorama model based on the registered point clouds.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

