CONTENT

1. Introduction to Kinect2. Some Libraries for Kinect3. Implement4. Conclusion & Future works

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Introduction to Kinect1. Kinect camera

Kinect is a motion sensing input device by Microsoft for the Xbox

360 video game console and Windows PCs. Based around a webcam-

style add-on peripheral for the Xbox 360 console, it enables users to

control and interact with Xbox 360 without the need to touch a game

controller, through a natural user interface using gestures and spoken

Kinect included of:

* A camera RGB with sensitive 640x480

* 3D depth sensor

* Microphone

* A motor to control kinect up and down

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Introduction to Kinect

Figure 1.1 Kinect camera

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Introduction to Kinect2. Calculating the depth on Kinect

On Kinect, we have IR projector combined IR camera to calculate

value image depth by Light Coding technology of Primesense.

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Introduction to Kinect

5

Introduction to KinectSuppose, Projector send a single light along the red line. It will be

captured by the camera once it hits a surface.

We have 3 plane, a reference plane, a plane close and a distant

plane.

When the point hits a surface in the close plane it will appear right

in the image than if it was hitting a surface in the reference plane.

Likewise, when the point is projected onto an object on a plane which

is more distant than the reference plane, the point will appear more to

the left.

When the origin and direction of the light is known beforehand,

and the horizontal position of the dot is known for a reference depth,

then it is possible to find out the depth of the surface which the point

hits based on its horizontal position in the cameras image plane

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Introduction to Kinect According to Nicolas Burrus, who pioneered with information

about the Kinect from his own experiments, the depth of a point z can

be calculated in meters from the raw disparity of the point d (as

provided by the Kinect hardware) using the following equation[9]:

z = 1.0/(-0.0030711016 x d + 3.3309495161)

d is an 11-bit integer which ranges from 0 to 2047. z will change

sign from positive to negative when d is around 1084, so values

beyond that are useless for depth measurement.

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Introduction to Kinect

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Implementation tests with the Kinect pointing straight at a wall

and found that it is was to unable to reliability measure depth values

below 50 cm (see gure 2). These facts mean that only d values of

about 434 to 1084 represent actual measurable depth values

Some Libraries for Kinect

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1. Kinect SDK beta

SDK beta released by Microsoft on 16th June 2011, SDK

beta allow to access all function of Kinect but This library only

support on Visual studio 2010.

* Support:

- Process sound

- Control motor angle of repose on Kinect.

- Good for the applications Skeleton tracking.

Some Libraries for Kinect

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2. Open NI

Open NI supports many API functions, can combine

middleware to increase ability for Kinect.

* Support:

- Detect gesture.

- Skeleton tracking

- Windows, Linux, Mac OSX

Some Libraries for Kinect

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3. Point cloud library

Point cloud is library to process image in 3D space. Having many

algorithms such as: filtering, surface reconstruction, segmentation,

feature estimation… PCL can apply on many platforms such as:

Window, Mac OS, Linux, Android,…