Intel RealSense D435i: a small update and a small historical excursion

The updated model of the camera RealSense 435, which received the index i, saw the light. Its distinctive feature is the built-in inertial sensor IMU (Inertial Measurement Unit). Doesn't the Intel RealSense name tell you anything? Then this post is for you. The development of this technology is described in detail here, in the company's blog, that you can tell its story without going beyond Habra. So we, perhaps, will do it, because lately RealSense is not to say that it is heard - although it is unfair.



Creative Camera with Intel Perceptual Computing SDK. year 2013
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3D imaging technologies have been developed at Intel since the early 2000s. The name RealSense appeared in 2014 , replacing the previously used Perceptual Computing ; Intel RealSense SDK and a prototype camera came out then. The principle of operation of 3D cameras consists in the simultaneous formation of two types of images: a normal RGB frame and a depth map obtained using infrared emitters and sensors. The image enriched with depth data can be used both for manipulating and analyzing objects (for example, background segmentation or moving the focus point), as well as a natural interface for controlling computer systems using facial expressions, hand and finger movements, gestures.


RGB photo and depth map for it

In the next 2 years, Intel has actively promoted RealSense on all fronts. Regular developer contests were held, numerous training and reference materials were published. In 2015, two serial RealSense cameras were released: the front F200 and the rear R200 . In this case, I even had a personal examination: on the 2016 New Year holidays, I had the opportunity to test both cameras at home . There were plans to introduce RealSense in laptops, smartphones and other computers , but later everything was limited to PC cameras.


Camera Intel RealSense SR300. 2016 year

Time passed, software was improved, new cameras of the second , then the third generation came out. Each time new improvements were made : the accuracy of determining the depth and usability increased, new recognition functions appeared. Intel continued to interact with the developers and receive feedback from them. In the blog, we actively published Russian-language translations of articles on the RealSense SDK - this was one of the few sources of information about RealSense in Russian. Which, in fact, is true to this day.


Intel RealSense SDK 1.0 allowed you to track up to 76 face key points, in the following versions the number of points increased

Currently relevant family of cameras Intel RealSense D400, released earlier this year. The family consists of two cameras: D415 and D435. D415 gives a clearer picture, but has a lower speed and a more distant minimum distance. The D435 is more suitable for AR / VR applications, as its global shutter works better with fast moving objects. More detailed characteristics of the cameras are given in the table.

	D415	D435
Application	Room / Outdoor
Depth determination	Dual IR beam
Shutter type	Sliding	Global
Pixel size	1.4 x 1.4 µm	3 x 3 microns
Depth field size	63.4 ° x 40.4 °	85.2 ° x 58 °
Depth field resolution	1280 x 720
RGB stream options	1080p @ 30 FPS
Depth range	0.16 - 10 m	0.11 - 10 m
Camera size (W x D x H)	99 x 20 x 23 mm	90 x 25 x 25 mm

Now the D435 camera has been upgraded - as already mentioned, the 6-axis inertial motion sensor IMU has been added to it. With all the smallness of the changes, they can’t be considered unimportant, since they open up a new realm of application. If earlier the camera was usually assumed to be a static object, then now the position and movement data are added to the 3-dimensional picture - valuable in their own right and, besides, increasing the accuracy of determining the depth. RealSense has become easier and more convenient to use in moving objects, such as drones or robots. And intelligent mobile devices, in turn, received a "third eye", which allows you to implement a fundamentally new functionality. Moreover, IMU works with the ROS framework (Robot Operating System) and, therefore, can be used with all ROS-compatible robot platforms.

Intel RealSense D435i is now in pre-order , shipments will begin on December 3, the current price is $ 199.