Re: [Elphel-support] Ordering stereo camera
Dear Andrey,Thank you. You’re so helpful. I apologize for late reply.The robot is an industrial type that will be used in outdoor conditions. There fore, it is very important to detect obstacles with high accuracy since the accuracy parameter is more critical than ambiguity. In addition, we must finish this project in the next month and we don't have enough time to code new software.According to above statements, we prefer to use Inline model. I hope we use H-model in future projects. what is difference of 2 stereo cameras(that has 4 lenses) with a 4 lenses stereo system?I'm hurry in my project please quote as soon as possible.I looking forward hearing from you.Best RegardsElham On Tuesday, August 30, 2016 12:41 AM, Elphel Support <support-list@support.elphel.com> wrote: Elpham, Using dual 2-lens system does not give you any advantage compared to two separate systems, and for research project I would rather use 2 separate, for simplicity. You know that there are many ways to process multi-view images, most use feature extraction and keypoints before calculating disparity and so the distance. Alternatively you can start from correlation (in most cases a superposition of the correlation and phase correlation) of the (usually just 2) images trying to get distance to objects that do not have easily identifiable feature but still have many high-frequency components. Both paths have some advantages and disadvantages, correlation provides better Z-resolution (you can easily operate with disparities being a small fraction of a pixel - like 0.1), but it is easy to get into ambiguous results, especially when the objects have some periodic structures. Using more than 2 view simultaneously can reduce ambiguity significantly, and finally get high precision distance measurements before the image is analyzed for feature extraction. Right now we do not have this code in FPGA, but it is one of our close targets that we'll work on when the base software for the cameras will be finished, so correlation will be done at "hardware" speeds in the same NC393-based cameras running new code. Meanwhile you could post-process images on a regular PC. I've seen much less works on the distance measurements with multiple-view systems compared to the standard 2-sensor systems, so that would give you an opportunity to do an interesting research. You could play (just online or download sources for analysis) with our "triclops" images that are linked on our web site to get an idea of the advantage of the multiple view systems. Andrey On Mon, 29 Aug 2016 12:27:28 -0700 Elham Omrani<elh.omr...@yahoo.com> wrote Dear Olga,Thank you for providing the requested information. Yes, we want to use Inline camera as 2 stereo cameras. Inner lenses are a stereo vision system with smaller baseline and focal length (suitable for near distance) and outer lenses are a stereo system with bigger baseline and focal length (for far distance). As you know, stereo vision error increases with increasing distance. Because of this, researchers uses 2 stereo camera in a unified system to decrease disparity error.If you use same baseline and focal lenses, What is your purpose of designing H- model or inline model with same baseline and focal lenses?About lens, In addition to 4.5 mm lens, what lens do you recommend (we prefer bigger than 4.5 focal lens)? I'm looking forward hearing from you.Elham On Monday, August 29, 2016 9:53 PM, Olga Filippova <support-list@support.elphel.com> wrote: Dear Elham, can you please explain the technical reasons for ordering inline camera? It looks like you plan to use Inline camera as 2 stereo cameras with 2 different bases. This is fine, but it has been done before, while the H-camera presents interesting research opportunities. Practically speaking we offer 4.5mm lenses (custom adjustment has been made to fit this lens to the camera, using 3 different adapter rings, as can be seen here: http://www3.elphel.com/importwiki?title=File:N125B04530W_adapter.jpeg) But we do not offer any 9 mm lenses - we have not tested any of 9mm lenses and we don't have these in stock, however you are welcome to purchase such lenses separately and install them on the camera. I am researching the exporting regulations to Iran. I think we can ship our camera products to Iran, but I need to receive answers from the exporting agency, to make sure. We offer standard 48V power supply that converts AC power from wall outlet to 48V DC power. The camera uses 3.3V, but the power supply has to be minimum 12V, or 18V better, especially for camera with 4 image sensors. You can power the camera from the boat power supply. For development it is nice to have a wall adapter, like the 48 V AC-DC converter we offer (or you can use the one you already have or can purchase locally). Best Regards, On Sun, Aug 28, 2016 at 12:55
Re: [Elphel-support] Ordering stereo camera
Hello Olga, Thank you for your attention to this matter. Yes, I remember, but Contrary to my opinion, my supervisor emphasis on purchasing Inline model. Therefore we decide to order inline model. so please quote for inline model, with 22 cm inner baseline(for inner lenses ) with 4.5 mm lens, and 44 cm outer baseline with 9 mm lens. We want to ship the camera to Iran. Do you send the camera with DHL post? According to your website, the required power for the 10393 system board is 3.3 VDC (http://wiki.elphel.com/index.php?title=10393) and Why do you use 48 v power supply ? what is required power for the camera? we have 12 VDC and 20-30 VDC(variable) on our robot, is it suitable for the camera? or we must purchase 48 v power supply ? I'm looking forward hearing from you. Elham On Monday, August 1, 2016 10:32 AM, support-list <support-list@support.elphel.com> wrote: Dear Elham, The most flexible solution will be something like this - http://blog.elphel.com/wp-content/uploads/2016/05/nc-393-printed-H-.jpeg , you will be able to change configuration if you'll need to. You can run opencv in the camera (not possible in the older NC353), but it will not be probably fast enough. On the other hand we plan to add more configurable image correlation processing into the FPGA (here id the block diagram of the current FPGA code), so you will be able to start with the external computer processing and later (probably in a year) to do some correlation in the camera in real time. Andrey On Sun, 31 Jul 2016 22:37:44 -0700 Elham Omrani<elh.omr...@yahoo.com> wrote Dear Andrey,Thanks for your good reply.My project is navigation and obstacle avoidance of a boat in outdoor. so I want to help me in choosing proper stereo camera.We want to use Opencv program.Yes, this program can use color or monochrome images.SinserlyElham On Monday, August 1, 2016 9:50 AM, support-list <support-list@support.elphel.com> wrote: Dear Elpham, There are many other issues that need to be considered when you select configuration of the stereo camera What type of objects you need to measure, their angular size What resolution do you need - angular and in distance What software are you going to use - what kinds of lens distortions it can tolerate/compensate? Does this software use color or monochrome images? And many more I would also recommend trying more than just 2 sensors - our experience indicates that it is much easier to avoid ambiguity before doing any feature extraction by just combining 3 or 4 images instead of 2. Andrey On Sun, 31 Jul 2016 22:03:09 -0700 Elham Omrani<elh.omr...@yahoo.com> wrote Dear Andrey, Thank you for your kindly answering and suggestion. I think NC353 camera with 5MPix resolution is enough for me(because of high speed of algorithm). in my project i need to see the depth of 50 meters(max).In your opinion is it possible? And the parameters of focal length and angle of view in what range should be? Elham ___ Support-list mailing list Support-list@support.elphel.com http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com ___ Support-list mailing list Support-list@support.elphel.com http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com
Re: [Elphel-support] Ordering stereo camera
Hello Olga,I apologize for delay. I must consult with my supervisor. According to our calculations, baseline 22 cm and focal lens 4.5 mm is suitable for inner cameras and for outer cameras we need larger focal length and we don't know exactly what kinds of lenses do you have for this purpose? because we want to use inner cameras in 4-20 meters, and outer camera in 20-100 meters(on your opinion what kind of lenses is suitable for 20-100 meters?). My supervisor emphasis on waterproofing, he said that H-model or Inline model that is waterproofing is appropriate for ours. Now, on your opinion, when is H-model waterproof enclosure ready?my friend lives in Georgia, can you send camera for her? how long does it take to get to her? I looking forward hearing from you. Best Regards Elham On Saturday, August 20, 2016 12:30 AM, Olga Filippova <support-list@support.elphel.com> wrote: Hello Elham, all camera models made with 3D-printed parts are just examples of the possible configurations. We offer our clients the freedom to modify camera configuration based on their needs and application. The camera with 4 sensors can be arranged in any way you want to design it. It is also possible to purchase the example Inline camera. It has a fixed baseline of 250mm, but it can be larger, limited only by the cable length. The longest cable we offer is 450 mm, so the largest baseline could be something like 700mm. Please note that we are working on the waterproof camera body for the H-camera, not the Inline camera. The 4 image sensors are synchronized and are taking images simultaneously. The lens we offer is Evetar, N125B04530WR1 with EFL=4.5mm, the focus is fixed on infinity. http://www3.elphel.com/ accessories You can also choose your own lens (C or CS mount, or M12 mount). Best Regards, On Thu, Aug 18, 2016 at 2:24 PM, Elham Omrani <elh.omr...@yahoo.com> wrote: Hello Olga,Thank you for your guidance.I have a few questions: In this Model (Inline model) is the baseline variable? In this system, are two cameras (or all of them) used at the same time? Does the lens have focus? Kind Regards Elham On Thursday, August 18, 2016 8:00 PM, Olga Filippova <support-list@support.elphel. com> wrote: Hello Elham, yes it will be possible to order the Inline model stereo camera with 4 sensors. As Andrey have mentioned, Elphel cameras are Free Software and Open Hardware and are distributed under GNU GPL license http://www.gnu.org/licenses/ gpl.html and CERN OHL http://www.ohwr.org/projects/ cernohl We would like to sponsor your project and follow it on Github repository (for example), or Sourceforge or Bitbucket with sources available for download. Here is an example of another project which had used Elphel cameras for their robots: https://bitbucket.org/ scinirov/scini/src/ 66a3b41e2763737dfa6ae5aab79a38 b86674d702/build/source/?at= master We have started designing the waterproof camera body, and some parts can be 3D-printed, however some parts we will order to be machined. Finishing the design, manufacturing parts, assembling and testing will take some time. Maybe you can make waterproof case faster. We will upload the parts for waterproof body as Open Hardware once it is ready, and you are welcome to share your design as well. Please let me know how would you like to proceed with the order, and if you will have any other questions. Best Regards, Olga On Tue, Aug 16, 2016 at 11:21 PM, Elham Omrani <elh.omr...@yahoo.com> wrote: Hello Andrey,Thank you for your detailed explanation. Ok, we can design waterproof enclosure for camera. Is it possible for me to order Stereo camera with 4 sensors Inline Model instead of H Model? because it is very suitable for ours.Kind Regards On Wednesday, August 17, 2016 7:05 AM, Elphel Support <support-list@support.elphel. com> wrote: Hello Elham, As I wrote you earlier - we do not have any waterproof camera, the only weatherproof (they withstand rain but can not go underwater) we manufacture is Eyesis4pi (it is more expensive device). Our users were able to use Elphel cameras deep under water (see project SCINI -https://www.google.com/ search?q=scini ), but it is their design, not ours. We provide open hardware cameras so you can download all our design files and develop the additions required for your particular application, and if your design is open too (so others can use your CAD files, software under acceptable FLOSS license) we may provide discounts (as I wrote earlier). We may develop some weather-proof H-camera ourselves, especially if there will be customers eager to pay for such product. But I can not promise to put all our work aside do develop such new hardware - we can do it only in our spare time (which currently we do not have). Your team has at least twice more members than we have at Elphel, so you can develop mechanical parts yourself (as other users do) faster (an
Re: [Elphel-support] Ordering stereo camera
Hello Andrey,Thank you for your detailed explanation. Ok, we can design waterproof enclosure for camera. Is it possible for me to order Stereo camera with 4 sensors Inline Model instead of H Model? because it is very suitable for ours.Kind Regards On Wednesday, August 17, 2016 7:05 AM, Elphel Support <support-list@support.elphel.com> wrote: Hello Elham, As I wrote you earlier - we do not have any waterproof camera, the only weatherproof (they withstand rain but can not go underwater) we manufacture is Eyesis4pi (it is more expensive device). Our users were able to use Elphel cameras deep under water (see project SCINI -https://www.google.com/search?q=scini ), but it is their design, not ours. We provide open hardware cameras so you can download all our design files and develop the additions required for your particular application, and if your design is open too (so others can use your CAD files, software under acceptable FLOSS license) we may provide discounts (as I wrote earlier). We may develop some weather-proof H-camera ourselves, especially if there will be customers eager to pay for such product. But I can not promise to put all our work aside do develop such new hardware - we can do it only in our spare time (which currently we do not have). Your team has at least twice more members than we have at Elphel, so you can develop mechanical parts yourself (as other users do) faster (and less expensive too) - we can definitely help you with consultations and tell if we think your design will work, what potential problems it may have. Andrey On Fri, 12 Aug 2016 06:03:26 -0700 Elham Omrani<elh.omr...@yahoo.com> wrote Hello Andrey,The longest of your cable is very good.because this camera will be used in outdoor condition, it is very important that it is waterproof. can you design H-camera with environmental protection?How will send us? and how many days does it take? ___ Support-list mailing list Support-list@support.elphel.com http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com
