e-con Systems provides the world's first Stereo Camera reference design - Capella for the embedded applications by developing this reference design based on the hugely popular TI OMAP35x (or TI Sitara AM37x or DaVinci DM37x) family of embedded application processors. The stereo camera reference design is based on the e-con's proprietary technology implemented on TI OMAP/DaVinci CPU and is provided along with the drivers and sample applications. e-con provides the Stereo Camera Reference design platform for the application and solution developers to develop their stereo camera applications based on our reference platform.
1.2 Why this reference design made out of OMAP3530 and not any other processor? Can it be done on any other processor?
As said earlier, e-con has devised a proprietary technique to combine left and right cameras of the Stereo Camera system and pass it on to the TI OMAP/DaVinci CPU and also implemented a technique to separate the left and right camera images before sending to the application. The application receives the pair of VGA resolution images from left and right camera at 30fps and the left and right images are pixel synchronous. The synchronous image capture was possible with the MT9V024 CMOS image sensors from Aptina. The proprietary technique of combining the left and right camera streams to a single stream that can be passed on to OMAP/DaVinci CPU and also separating them out by making use of the OMAP/DaVinci camera pipeline is developed by e-con and has been validated on the OMAP/DaVinci CPUs for Stereo Camera resolution of VGA @ 30fps. For other processors, e-con can verify the feasibility of porting our proprietary technique.
1.3 What are the things I get as soon as I purchase the kit from e-con Systems?
The Stereo Camera Reference Design kit contains the complete development kit with stereo VGA camera and the sample applications. For the detailed list of kit contents, please visit the Capella product page.
2. Reference design - HW
2.1 What does e-con Systems' reference design provide for developers and OEMs?
e-con provides the world's first stereo camera reference design for embedded applications in Top of TI OMAP35x / DM37x Processors. The reference design is self contained and is provided with OpenCV SDK along with sample applications. This enables the developers to start their application development on our stereo camera reference design from the day one. TI OEM's can customize this stereo camera hardware and integrate this in to their systems or even license this stereo camera design from e-con.
2.2 How do we know that the cameras are perfectly in Sync? Is there any metrics to detect how closely the Sync is?
The CMOS image sensors used in this Stereo camera are from Aptina and support external synchronization and e-con's design ensures that the left and right sensors are operated synchronously. The left and right cameras are interfaced to the TI OMAP35x or TI Sitara/DaVinci processor through e-con's hardware logic that ensures that the synchronous nature of left and right sensors are preserved all through the application. The application receives the VGA images at 30fps from each left and right camera (Total of VGA @ 60fps) which are exposed exactly at the same time. There is no metric to define the synchronous nature, but the synchronous nature can be demonstrated with accurate stop watch or similar objects. Here is a sample video that demonstrates the synchronous capture of the two cameras.
2.3 What is the camera sensor that is used in the Capella reference design?
The sensor used in the reference design is MT9V024 (monochrome) from Aptina.
2.4 Can the camera support color?
The current version of stereo camera does not support color. Only monochrome sensors are supported now. For color Stereo camera contact email@example.com
2.5 What is the shutter type on the sensor?
The sensor is global shutter sensor and the MT9V024 sensor is operated in Global Shutter mode in our reference design.
2.6 What is the lens mount used?
The lens mount used in the Stereo Camera reference design is S-mount M12 lens holder (M12 P0.5 lenses are supported by default). e-con can customize this camera for other lens mounts as well as other baseline. The baseline refers to the distance between the left and right cameras and this can also be customized.
2.7 Can I change the lens mount from S mount to C mount?
Yes, we can customize the stereo camera to support C/CS mount lens.
2.8 Where can I get the datasheet of the lens?
Please contact e-con sales team to get the lens datasheet.
2.9 Can I have a different sensor integrated other than the MT9V024? The MT9V024 is a small resolution sensor and I would like to integrate OV5642 since it as 5MP. Along with the depth, I also want to shoot a picture.
The MT9V024 sensor support external synchronization input with Master/Slave support. The OV5642 does not support this feature and hence synchronous capability cannot be demonstrated on the OV5642 sensor.
2.10 What are the various constituents of the Capella reference design?
The major components of the reference design are:
Stereo camera board with S-mount lens holder and 5.6mm focal length lenses. The stereo camera is pre-calibrated for this setup.
Gumstix Overo + Tobi board to which the stereo camera board is interfaced with
Connectivity options of Tobi board for HDMI display, Ethernet, debug port and USB host interface
Binaries of OS image with stereo camera driver, sample applications etc
Source code for the sample applications and the device driver.
Plain Stereo camera implementation using V4L2 architecture with sample application demonstrating synchronous stereo operation (image capture)
OpenCV based Stereo camera SDK with support for calibration and sample applications.
2.11 We don't need the Overo module or the Tobi board. We only need the camera board that connects to the Overo module. Can we buy that alone?
2.12 Can I buy the Overo module and the Tobi board directly from Gumstix and use e-con's camera board? Is this recommended?
That is not recommended for starters. e-con's stereo camera boards are available only to customers who have already purchased the complete reference design and who are quite familiar with our stereo camera board integration. Once you became familiar with our stereo camera board/driver integration, you can buy only the stereo camera boards and integrate with either your own platform or Gumstix Overo platform (Tobi or any other daughter board).
2.13 I would like to buy my own lens instead of the lens provided by e-con Systems. Is this possible?
The lenses are chosen after considering various parameters and then calibrated using the calibration software provided as part of OpenCV SDK. If you try to use any other lens or if you have done any modifications to the lens set up provided in the e-con Stereo camera, then you must calibrate the new lens or new lens position using the OpenCV SDK. For the stereo camera analysis, the calibration is the crucial process and the calibration accuracy determines the overall accuracy of the stereo camera system. The calibration is easily lost, even with the slightest change in the lens position. If you use your own lens, then you must do the calibration thoroughly before moving on to next task.
2.14 What are the various Overo modules that are supported if I just plan to buy the camera board alone?
The stereo camera reference design is based on Gumstix Overo+Tobi platform. As the stereo camera is interfaced to Overo module directly, the stereo camera can be interfaced to Overo or Overo STORM directly.
2.15 What is the pricing of this reference design?
Annual volume forecast (pl indicate for each year):
Pilot production date:
Mass production date:
3. Reference design - SW
3.1 What are the sample applications provided along with this reference design kit?
A sample application based on V4L2 implementation describes the stereo camera interfaces to the application. This application can be used to capture images from left and right sensors individually or collectively. The same sample application can capture the frames from left and right sensor and prove the synchronous nature of the stereo camera.
3.2 I understand that e-con Systems' provides sample depth measurement applications along with the kit. What is the number of bits/pixel information that is provided?
The depth map is calculated from the disparity map computed from the left and right images. The calculated depth map is 8bits per pixel.
3.3 Can I get the source code of this application?
The source code for the sample applications are provided as part of the software package when you buy the complete Stereo Camera Reference design kit from e-con.
3.4 Can I get the underlying camera hardware schematics and the Linux kernel?
Yes, you can license the complete stereo camera reference design to get access to hardware schematics and the Linux kernel. The device driver source is provided along with the evaluation kit. Please contact firstname.lastname@example.org for more information.
3.5 What is the Linux kernel version used?
As of now, Linux kernel version 2.6.37 is supported. e-con continuously updates the kernel version supported. If you need any other kernel version, please contact e-con sales team with more details. e-con can evaluate the feasibility and come back to you with the commercial proposal.
3.6 What is the development environment for the applications?
The default Gumstix Overo development tools and environment is used for the stereo camera development also.
3.7 Will I be able to change the root file system so that I can get the latest file system with the new compilers?
Yes, but before that e-con recommends that you get engineering resources from e-con to support these tasks.
3.8 What is the GNU tool chain version?
3.9 Can I use the latest GNU tool chain to compile my Stereo applications
YES, but you need to rebuild the QT and OpenCV (Apply the Stereo Engine related patch for OpenCV) Library from source using your GNU tool chain.
3.10 Is this application production ready or does it have more to be done?
The applications provided are samples and not production-ready. The developers have to use these sample applications as reference to build their solutions.
3.11 What is the maximum working distance that can be measured?
The maximum working distance varies with the lens. With our default lens, the maximum working distance is about 300cm, beyond which the depth accuracy drops down.
3.12 Can the working distance be varied? If yes, how?
This requires choosing different lens and also calibrating the camera for the new lens. see also 3.13
3.13 I want to have the depth measurement from 1-10 meters. Can it be done?
This may not be possible, as at 10m distance, the disparity seen on the sensors may be too small to detect the depth. This requires changing the distance between two cameras. e-con can do the integration for the same.
3.14 As soon as I buy the reference design, can I start recording depth measurements or do I have to do any preparation for this?
The sample application provided with the kit demonstrates the depth measurement. Please refer this application user manual Capella Depth Measurement Application Note. For more information about this sample application.
3.15 What is Calibration? Why should I do that?
Camera images usually contain small amount of spherical distortion known as goldfish eye bowl effect. Especially linear featured items like straight wooden or steel bar, door edges appear to be round edged at image edges. Stereo camera calibration has to be done in-order to determine nature of distortion and to relatively reduce error further. Calibration can be done by training camera to observe test patterns like chess board, spots, lines or squares.
The task of camera calibration is to determine the parameters of the transformation between an object in 3D space and the 2D image observed by the camera from visual information (images). The transformation includes
Extrinsic parameters (sometimes called external parameters): orientation(rotation) and location (translation) of the camera, i.e., (R, t);
Intrinsic parameters (sometimes called internal parameters): characteristics of the camera, i.e., (α,β,γ, u0, v0).
These parameters can further be used to acquire the knowledge of depth information of an object in the stereo system.
3.16 Is there any way that I can just use the reference design directly without making any Calibration? I find it too long a process.
Yes, the calibration is a length process and requires patience. The development kit comes with precalibrated set up. If the lens and camera are not adjusted, then there is no need for recalibration. If there is any change in the lens, even a slight movement of the lens thread may cause calibration data to be invalid. Then the developer has to calibrate it again.
3.17 I would like the lens to be fitted in and sent to me so that everything is recalibrated and I don't need to do calibration when I get them. Is this possible?
The lens comes fitted in the camera development kit. As long as the lens is not moved or adjusted, the precalibration data works fine. In any case, if the developer finds erroneous results, he has to calibrate it again.
3.18 If I use my own lens and not the ones provided by e-con Systems, is there any thing that I have to take care of before I start working with the application software?
Please refer 2.13
3.19 Can I get the depth of each and every pixel in the depth measurement application?
No, the depth measurement application detects the circular object (only one circle is expected in the scene) and detects the distance of this circular object from the camera. This is provided just as a sample.
3.20 Does the depth calculation involve the DSP of the OMAP or the DM3730 that is featured in the Overo storms?
No, DSP is not used.
3.21 Does e-con have access to application developers who can develop applications for me around your reference design?
3.22 What is the resolution that can be captured? What is the frame rate at this resolution?
The resolution is VGA@30fps (left and right combined).
4. Customization services
4.1 I want to design my own Stereo vision system but I don't plan to use the OMAP3530 processor or the DM3730. Will e-con support me in my endeavor?
4.2 We are planning to build a Panoramic camera view with 4 cameras in sync with each other. Can we have a system built with the Gumstix?
No, we cannot support 4 cameras on a single Gumstix Overo module. However we can provide other custom solutions for this.
4.3 I am a stereo application developer and I plan to develop application on top of e-con Systems' reference design. For this, I require better support in terms of kernel, drivers etc. Whom should I contact for this?
4.4 I would like to go for a higher resolution camera. 1.3MP or higher is good enough for my application. Is this possible?
This is currently under development. e-con is working with sensor manufacturers for this and also on the complex hardware for higher resolution.
4.5 I want to do a single board design with the OMAP3530 processor and the camera board integrated. Can e-con help me in getting this?
Yes, e-con has churned out lot of products based on TI OMAP/DaVinci processors running Windows CE/Linux. e-con can definitely help you out here. For further details, please contact email@example.com
4.6 I need to use a color sensor instead of a monochrome. Do I have options?
As of now, we don't have color sensor solutions. But this is under development.