Summary of Contents for nerian SP1
- Page 1 SP1 Stereo Vision System User Manual (v1.0) August 28, 2015 VISION TECHNOLOGIES Dr. Konstantin Schauwecker Nerian Vision Technologies Gotenstr. 9 70771 Leinfelden-Echterdingen Germany Email: service@nerian.com...
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Page 2: Table Of Contents
6 Hardware Setup 6.1 Connecting the SP1 ......6.2 Supported Cameras ...... - Page 3 9 API Usage Information 9.1 General Information ......25 9.2 ImageTransfer Example ..... . 26 9.3 AsyncTransfer Example .
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Page 4: Functionality Overview
The SP1 stereo vision system is a stand-alone processing system for performing stereo matching in real time. It is connected to two industrial USB cameras that provide input image data. The SP1 correlates the images of both cameras and produces a disparity map, which is transmitted through gigabit ethernet. -
Page 5: Image Rectification
3.3 Image Rectification 4 MECHANICAL SPECIFICATIONS Figure 1: (a) Front, (b) rear, (c) side and (d) top view of SP1 with dimensions in millimeters. Image Rectification Horizontal displacement: 31 to +31 pixels Vertical displacement: 31 to +31 pixels Interpolation: Bilinear Mechanical Specifications... - Page 6 4.2 Mounting 4 MECHANICAL SPECIFICATIONS Figure 2: SP1 with attached mounting plate. Figure 3: Mounting plate dimensions in millimeters.
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Page 7: Physical Interfaces
Figure 4: Interfaces on (a) front and (b) rear housing side. Physical Interfaces Figures 4a and 4b show the interfaces on the SP1’s front and backside. The power jack is located on the backside, and it needs to be connected to the supplied power adapter or an equivalent model. -
Page 8: Hardware Setup
SP1’s ethernet port. Alter- natively it is possible to connect the SP1 to a switched network. However, you will have to ensure that the network is capable of handling the high bandwidth data that is transmitted by the device. -
Page 9: Camera Alignment
The baseline distance should be adjusted in conjunction with the lenses’ focal length. An online tool for computing desirable combina- tions of baseline distance and focal length can be found on the Nerian Vision Technologies website External Trigger For stereo matching it is important that both cameras are synchronized, mean- ing that both cameras record an image at exactly the same point of time. -
Page 10: Processing Results
This time, all edges of the calibration board are perfectly straight. When performing stereo matching, the SP1 additionally outputs the rec- tified left camera image. This allows for a mapping of features in the visible image to structures in the determined scene depth and vice versa. - Page 11 Q, which is computed during camera calibration and can be obtained from the review calibration page of the SP1’s web interface (see Section 8.7). The 3D location x y z of a point with image coordinates (u, v) and disparity d can be reconstructed as follows:...
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Page 12: Configuration
Figure 9b invalid disparities have been depicted as black. Configuration The SP1 is configured through a web interface, which can be reached by en- tering the IP address of the SP1 in your browser. The default address is http://192.168.10.10. Please configure the IP address and subnet mask of your computer appropriately, such that this interface can be reached. -
Page 13: Preview
(see Section 6.1). For using the preview page you require a direct connection to the SP1. An in-between proxy server or a router that performs network address translation (NAT) cannot be used. - Page 14 8.2 Preview 8 CONFIGURATION Figure 11: Screenshot of configuration preview page. ity of the computed disparity map. In particular, sub-pixel accuracy is not available, and your browser might not be able to display the disparity map at the full camera frame rate. To receive a full-quality preview, please use the SpCom sample application, which is described in Section 10.
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Page 15: Processing Settings
Figure 12. The most relevant option is the operation mode, which can be set to one of the following values: Pass through: In this mode the SP1 forwards the imagery of the selected cameras without modification. This mode is intended for verifying that both cameras are functioning correctly. -
Page 16: Cameras
All detected cameras are listed in the camera selection list. A source is listed for each camera, which identifies the utilized camera driver. To allow for an easy evaluation, the SP1 ships with an example stereo sequence on its internal... -
Page 17: Camera Settings
8.4 Cameras 8 CONFIGURATION Figure 13: Screenshot of configuration page for camera settings. memory. This example sequence appears as a virtual left and virtual right camera. To choose a particular camera, you have to tick either the use as left or use as right radio button, for selecting the camera as the left or right camera of the stereo pair. -
Page 18: Recommended Settings For Point Grey Cameras
In this case, the SP1 will query the settings of the left camera and adjust the right camera’s settings accordingly. -
Page 19: Trigger
You require a calibration board, which is a flat panel with a visible calibration pattern on one side. The pattern that is used by the SP1 consists of an asymmetric grid of black circles on a white background, as shown in Figure 16. - Page 20 8.6 Camera Calibration 8 CONFIGURATION Figure 15: Screenshot of configuration page for camera calibration. Figure 16: Calibration board used by SP1.
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Page 21: Recording Calibration Frames
The more frames you record, the more accurate the computed calibration will be. However, more frames also cause the computation of the calibration parameters to take longer. The SP1 supports the recording of up to 40 cali- bration frames. The recording of calibration frames can be simplified by activating the auto capture mode. -
Page 22: Performing Calibration
8.7 Reviewing Calibration Results 8 CONFIGURATION Figure 17: Example calibration frame with detected calibration board. 8.6.3 Performing Calibration Once you have recorded a sufficient number of calibration frames, you can initiate the calibration process by pressing the calibrate button in the control section. - Page 23 8.7 Reviewing Calibration Results 8 CONFIGURATION Figure 18: Screenshot of configuration page for reviewing camera calibration. Figure 19: Example for evaluating vertical image coordinates. of both cameras, which have been rectified with the current calibration pa- rameters. Please make sure that corresponding points in the images of both cameras have an identical vertical coordinate.
- Page 24 8.7 Reviewing Calibration Results 8 CONFIGURATION section. These parameters are: : camera matrices for the left and right camera. : distortion coefficients for the left and right camera. : rotation matrix for the rotation between the original and rectified camera images. : projection matrices in the new (rectified) coordinate systems.
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Page 25: Network Settings
The possible options are TCP and UDP. Due to the high- bandwidth real time data, we recommend using UDP. If TCP is selected, the SP1 will open up the server port 7681 and wait for a client computer to connect before transmitting data. Because UDP is a connection-less protocol, data transmission starts instantly if UDP is selected. -
Page 26: Api Usage Information
The libvisiontransfer API provides functionally for receiving the processing results of the SP1 over a computer network. Furthermore, the API also allows for the transmission of image data. It can thus be used for emulating an SP1 when performing systems development. -
Page 27: Imagetransfer Example
// C r e a t e an image t r a n s f e r o b j e c t t h a t r e c e i v e s data from // t h e SP1 on t h e d e f a u l t p o r t u s i n g UDP I m a g e T r a n s f e r i m a g e T r a n s f e r ( I m a g e T r a n s f e r : : UDP_CLIENT, NULL, "... - Page 28 9.2 ImageTransfer Example 9 API USAGE INFORMATION s t d : : c o u t << " R e c e i v i n g image " << i << s t d : : e n d l ; // A l t e r n a t i n g l y r e c e i v e t h e f i r s t and s e co n d image f o r i n t...
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Page 29: Asynctransfer Example
// C r e a t e an async t r a n s f e r o b j e c t t h a t r e c e i v e s data from // t h e SP1 on t h e d e f a u l t p o r t u s i n g UDP A s y n c T r a n s f e r a s y n c T r a n s f e r ( I m a g e T r a n s f e r : : UDP_CLIENT, NULL, "... -
Page 30: D Reconstruction
9.4 3D Reconstruction 10 SPCOM SAMPLE APPLICATION // Write PGM h e a d e r i n t maxVal , b y t e s P i x e l ; ( format == I m a g e P r o t o c o l : : FORMAT_8_BIT) { maxVal = 2 5 5 ;... - Page 31 Perform color-coding of disparity maps. Write received data to image files. Transmit a set of images over the network and thus emulate the SP1. SpCom should be run from a terminal in order to supply command line arguments and to view the printed status messages. If the graphical mode is not disabled, then SpCom opens up a window for displaying the received images.
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Page 32: Support
12 WARRANTY INFORMATION Color code the disparity map. -s directory Server mode (emulating SP1). The images in the given di- rectory will be read and sent out over the network. Non-graphical mode. No display window will be opened. -f number Limits the frame rate to the given value. -
Page 33: Open Source Information
13 OPEN SOURCE INFORMATION Open Source Information The firmware of the SP1 contains code from the open source libraries and applications listed in Table 1. Source code for these software components and the wording of the respective software licenses can be obtained from the open source information website . - Page 34 13 OPEN SOURCE INFORMATION Inc, Addison-Wesley, Advanced Micro Devices Inc., Alexander Chemeris, Alexander Neun- dorf, Alexandre Benoit, Alexandre Julliard, Andreas Dilger, Andrei Alexandrescu, Andrey Kamaev, Annecy le Vieux and GIPSA Lab, Argus Corp, Arren Glover, AWare Systems, Bap- tiste Coudurier, Chih-Chung Chang, Chih-Jen Lin, Christopher Diggins, Clement Boesch, David G.
- Page 35 Revision History 13 OPEN SOURCE INFORMATION Revision History Revision Date Author(s) Description v1.0 August 28, 2015 KS List of compatible cameras, infor- mation on IDS cameras, software download link, extended open source information, general im- provements. v0.1 July 30, 2015 Initial revision...