We propose a novel method to measure and analyze depth resolution in near range. Depth resolution is the smallest depth difference that can be detected by a depth camera, which is an important parameter but is hard to be measured accurately. Intuitively, a stair-shaped target is preferred to measure depth resolution but has many limitations. To overcome the difficulties, we use a flat target and move a depth camera at specified steps to form a stair-shaped depth map. Then, the depth map is compressed to one-dimensional profile by an average cross-section method. The 68-95-99.7 rule is applied for identifying the depth resolution. In order to obtain accurate data, a computer-controlled positioning platform is used to move or rotate a depth camera and a target in high precision. Three types of targets are made and tested, including a stair-shaped metal plate, a flat acrylic board, and a tensioned electric screen. A procedure is provided for aligning the optical plane of depth camera to the target before measuring. The Intel RealSense D400 series depth cameras are adopted for verification. Their theoretical depth resolution is derived and compared to the measured depth resolution. The effect of image resolution (x, y) on the depth resolution (z) is also analyzed. The experimental results offer useful information for researchers to design a depth camera and verify its depth resolution.

中文翻译：

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主动立体相机的深度分辨率测量与分析

我们提出了一种新的方法来测量和分析近距离范围内的深度分辨率。深度分辨率是深度相机可以检测到的最小深度差，这是一个重要参数，但很难准确测量。直观上，阶梯形目标是测量深度分辨率的首选，但有很多限制。为了克服这些困难，我们使用了平坦的目标，并按指定步骤移动了深度摄像头，以形成阶梯形的深度图。然后，通过平均横截面方法将深度图压缩为一维轮廓。68-95-99.7规则适用于识别深度分辨率。为了获得准确的数据，计算机控制的定位平台用于高精度地移动或旋转深度相机和目标。制定并测试了三种类型的目标，包括楼梯形的金属板，平坦的丙烯酸板和张紧的电屏。提供了在测量之前将深度相机的光学平面对准目标的过程。验证采用了英特尔实感D400系列深度摄像头。推导出其理论深度分辨率并将其与测得的深度分辨率进行比较。还分析了图像分辨率（x，y）对深度分辨率（z）的影响。实验结果为研究人员设计深度相机并验证其深度分辨率提供了有用的信息。推导出其理论深度分辨率，并将其与测得的深度分辨率进行比较。还分析了图像分辨率（x，y）对深度分辨率（z）的影响。实验结果为研究人员设计深度相机并验证其深度分辨率提供了有用的信息。推导出其理论深度分辨率，并将其与测得的深度分辨率进行比较。还分析了图像分辨率（x，y）对深度分辨率（z）的影响。实验结果为研究人员设计深度相机并验证其深度分辨率提供了有用的信息。