Image source: extremetech.com
Lidar systems and depth cameras have become part of today’s depth-sensors in the digital market. The sensors supplement the current monocular RGB images by providing per-pixel depth information of the target objects.
The depth- sensors accurately measure the distance and wavelength of a target object and return a 3D representation. Although the two technologies are similar in nature, they also have some variances.
Lidar Vs Depth Camera:
1. DEFINITION:
Lidar: Lidar system is a remote sensing technology used to estimate the distance and depth range of an object.
Depth Camera: Depth or range cameras sense the depth of an object and the corresponding pixel and texture information.
2. PRINCIPLE:
Lidar: Measure the time a small light on the surface takes to return to its source. It uses a laser beam to measure how pulses of light bounce off and return to the starting point. This determines the distance of the object.
Depth Camera: Measure the intensity of the ambient light through the illumination of the target object. Uses Time-of-Flight remote sensing to measure the reflected light which comes from its own light-source emitter.
3. MAPPING AND NAVIGATION ENVIRONMENT:
Lidar: Provides 3D mappings in an exterior area. The Lidar systems Global position system provides the accurate geographical information of an object. It cannot navigate in the interior areas of a building. Works for outdoor sensing
Depth Camera: Depth sensing technology provides you with 3D models of building interiors. It shows the exact location of a target object in a building. Works for both indoor and outdoor sensing.
4. TECHNOLOGY:
Lidar: It uses pulse laser light to illuminate the target object and measure the reflected pulses with a sensor. The object’s distance is derived using the laser wavelength and the return time. Terrestrial mapping applications are used to generate high-resolution depth maps.
Depth Camera: It measures the depth of the target object by illuminating the object with controlled patterns of dots using infra-red light or LED and analyze the reflected light. It uses the stereo vision technique to determine the depth of an object.
5. AUGMENTED REALITY, AR:
Lidar: Lidar scanners are used to provide 3D mappings of an object. This allows other AR systems to have accurate overlay data on top of the detailed 3D mapping. The created 3D models determine virtual reality as well as visualize the location of virtual objects.
Depth Camera: It utilizes depth cameras to provide a soft depth sensor with an instant depth estimation of the physical object. Range cameras allow the occlusion of both virtual objects and physical objects.
6. COST:
Lidar: High-resolution Lidar system is very expensive compared to depth camera hardware.
Depth Camera: Cameras are inexpensive with cost-effective hardware and high-resolution sensors.
7. ENVIRONMENTAL EFFECTS:
Lidar: The laser sensors are susceptible to bad weather conditions.
Depth Camera: They are susceptible to unique noise such as range ambiguity, scattering, and motion blur.
8. OVERALL PERFORMANCE:
Lidar: Lidar systems only provide 3D mappings of the object shape. It has limited capability to interpret roadway information like landmarks and drivable paths.
Depth Camera: Cameras create high-definition mapping data by identifying target object shape, appearance, and texture. Not only capture objects but also the landmarks, drivable paths among other data making it a reliable sensor.
9. DISTANCE AND ACCURACY OF DATA:
Lidar: Lidar systems have limited range and are more accurate in low range objects with high-resolution.
Depth Camera: They can gain a high-resolution image of distance objects thus making them able to see objects that can’t be accessed by low-resolution Lidar.
10. COLOR PATTERNS:
Lidar: Lidar systems do not provide color information on target objects. It uses lasers to create the points between the source and reflected object.
Depth Camera: Uses infrared light color patterns to display the reflected object.
Conclusion:
Depth cameras and Lidar technologies are shaping the future by helping the devices and machines perceive their surrounding environments. Depth cameras combine Infrared pattern emitters and Infrared Stereo to improve the performance of the cameras in low-light conditions
