RGB-D sensors (sensors with RGB camera and Depth camera) are novel sensing systems that capture RGB images along with pixel-wise depth information. Although they are widely used in various applications, RGB-D sensors have significant drawbacks including limited measurement ranges (e.g., within 3 m) and errors in depth measurement increase with distance from the sensor with respect to 3D dense m...

Quality analysis of a collected depth dataset is important in order to find the statistic accuracy and variance of the depth data. Any systematic errors have to be identified and if possible minimised. It is also important to establish if the data fulfils the accuracy standard stated in the survey specification. The accuracy of collected depth data depends on several parameters such as the accu...

RGB-Depth (or RGB-D) cameras are increasingly being adopted for real-world applications, especially in areas of healthcare and athome monitoring. As for any other sensor, and since the manufacturer’s parameters (e.g., focal length) might change between models, calibration is necessary to increase the camera’s sensing accuracy. In this paper, we present a novel RGB-D camera-calibration algorithm...

Radiochromic film for spot-scanning QA provides high spatial resolution and efficiency gains from one-shot irradiation for multiple depths. However, calibration can be a tedious procedure which may limit widespread use. Moreover, since there may be an energy dependence, which manifests as a depth dependence, this may require additional measurements for each patient. We present a one-scan protoc...

The gamma ray interaction depth in 3-D position scnsitive CdZnTe dctectors is currently determined by the pulse height ratio ofthe cathode signal to the anode pixel signal (CIA ratio). In expcriments with our 3-D CdZnTe dctectors, thc photopeak area as a fuuction of the CIA ratio deviates from the expected exponential attcnuation with depth. This indicatcs that the CIA ratio is not proportional...

Much research has emphasized stereo disparity as a source of depth information. To a lesser extent, camera vergence and lens focus have also been investigated for their utility in depth recovery. Each of these visual cues exhibits shortcomings when used individually in the sense that none alone can be used to reconstruct surfaces for real scenes that often cover a wide field of view and a large...

Color-depth cameras (RGB-D cameras) have become the primary sensors in most robotics systems, from service robotics to industrial robotics applications. Typical consumergrade RGB-D cameras are provided with a coarse intrinsic and extrinsic calibration that generally does not meet the accuracy requirements needed by many robotics applications (e.g., high accuracy 3D environment reconstruction an...

This paper describes a novel embedded system capable of estimating 3D positions of surfaces viewed by a stereoscopic rig consisting of a pair of calibrated cameras. Novel theoretical and technical aspects of the system are tied to two aspects of the design that deviate from typical stereoscopic reconstruction systems: (1) incorporation of an 10x zoom lens (RainbowH10x8.5) and (2) implementation...

Features of leaves can be more precisely captured using 3D imaging. A 3D leaf image is reconstructed using two 2D images taken using stereo cameras. Reconstructing 3D from 2D images is not straightforward. One of the important steps to improve accuracy is to perform camera calibration correctly. By calibrating camera precisely, it is possible to project measurement of distances in real world to...

Laser beams emitted from the Geoscience Laser Altimeter System (GLAS), as well as other spaceborne laser instruments, can only penetrate clouds to a limit of a few optical depths. As a result, only optical depths of thinner clouds ( about 3 for GLAS) are retrieved from the reflected lidar signal. This paper presents a comprehensive study of possible retrievals of optical depth of thick clouds u...