深度感知简介

How it works

Depth Perception gives an application the ability to understand the distance toobjects in the real world. To implement Depth Perception, manufacturers ofTango devices can choose among common depth technologies, includingStructured Light, Time of Flight, and Stereo. Structured Light and Time ofFlight require the use of an infrared (IR) projector and IR sensor; Stereo doesnot.

Depth Perception can be useful in a number of ways:

• A game might want to detect when the user is approaching a wall or other object in the area and have that be part of the gameplay.

• By combining Depth Perception with Motion Tracking, the device can measure distances between points in an area that aren't in the same frame.

• Depth data can be associated with the color image data to look up the color for a point cloud for texturing or meshing.

怎么运行的

深度感知使应用程序能够理解现实世界中到对象的距离。 为了实现深度感知，Tango设备的制造商可以选择常见的深度技术，包括结构光，飞行时间和立体声。结构光和飞行时间需要使用红外（IR）投影仪和红外传感器; 立体声不。

深度感知可以在许多方面有用：

     游戏可能想要检测用户何时接近该区域中的墙壁或其他对象，并且将其作为游戏玩法的一部分。

     通过组合深度感知和运动跟踪，设备可以测量不在同一帧中的区域中的点之间的距离。

     深度数据可以与彩色图像数据相关联以查找用于纹理化或网格化的点云的颜色。

Usability tips

Current devices are designed to work best indoors at moderate distances (0.5 to4 meters). This configuration gives good depth at a distance while balancingpower requirements for IR illumination and depth processing. It maynot be ideal for close-range object scanning or gesture detection.

For a device that relies on viewing IR light using its camera, there are somesituations where accurate Depth Perception is difficult. Areas lit with lightsources high in IR like sunlight or incandescent bulbs, or objects that do notreflect IR light, cannot be scanned well.

可用性提示

当前设备设计为在中等距离（0.5至4米）的室内最佳工作。 该配置在远距离处给出良好的深度，同时平衡IR照明和深度处理的功率要求。它对于近距离物体扫描或手势检测可能不是理想的。

对于依赖于使用其相机观看IR光的设备，存在难以精确的深度感知的一些情况。 用红外灯高亮的区域，如阳光或白炽灯泡，或不反射红外光的物体，不能被很好地扫描。

Point clouds

The Tango APIs provide a function to get depth data in the form of apoint cloud. This format gives (x, y, z) coordinates for as many points in thescene as are possible to calculate. Each dimension is a floating point valuerecording the position of each point in meters in the coordinate frame of thedepth-sensing camera.

点云

Tango API提供以apoint云的形式获得深度数据的功能。 这种格式给出了可能计算的场景中许多点的（x，y，z）坐标。每个维度是浮点，记录在深度感测摄像机的坐标系中每个点的位置（以米为单位）。

For more information, see theTangoPointCloud struct API reference.

有关详细信息，请参阅TangoPointCloud struct API参考。