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 AM, Elham Omrani <elh.omr...@yahoo.com>
wrote:
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 Wednesday, August 3, 2016 1:44 AM, support-list
<support-list@support.elphel. com> wrote:
Dear Elham,
Elphel is a small company, and all our funds come from the product sales - we
do not use any government funding, private investments or crowdfunding. Our
margin is lower than 50%, so such discount means that we already pay more for
the components than receive for the camera sale.
That is OK, we do sometimes donate to interesting projects, but right now we
are still in the process of upgrading to the new line of the cameras, that
involves rather expensive R&D that does not pay back immediately. We use
now all the available resources to shorten the transition time, it is going
well so far, but still there is work to be done.
We may consider donating to interesting projects in the future, but right now
it is all what we can afford to offer.
As for the brochure - we do not yet have any for the new camera, all the
information we have ourselves is posted online. Code is on Github
(https://github.com/Elphel), more information on our wiki
(http://wiki.elphel.com/index. php?title=10393 , http://wiki.elphel.com/index.
php?title=Poky_2.0_manual, ) more picture in the blog post -
http://blog.elphel.com/2016/ 05/3d-print-your-camera- freedom/
Here - http://wiki.elphel.com/index. php?title=Elphel_camera_ assemblies (the
link is on our home page) you can take our camera apart and look at each
component (all components have CAD files on our wiki - files you can use to
build the parts).
Andrey
---- On Tue, 02 Aug 2016 08:15:32 -0700 Elham Omrani
<elh.omr...@yahoo.com> wrote ----
Dear Andrey,
Thank you for your excellent suggestion. we will be very happy if you
contribute in this project. could you please raise the percent of your
sponsorship? furthermore, is it possible to send us the NC393-H brochure?
we are sincerely grateful for your contribution
Elham
Dear Elham,
Your project seems very interesting. We can sponsor 50% of the cost of the
NC393-H for your team and provide additional technical support. Will the result
of your research be open for others to reproduce?
Andrey
---- On Mon, 01 Aug 2016 01:27:18 -0700 Elham Omrani
<elh.omr...@yahoo.com> wrote ----
Dear Andrey
I'm PhD student and in my thesis is "Implementation of stereo vision system for
obstacle detection in solar boat"
this is my website:http://emorvarid.ut.ac.ir/Members.htm
Elham
On Monday, August 1, 2016 11:27 AM, support-list
<support-list@support.elphel. com> wrote:
Dear Elham,
What kind of project is it ? Is it a personal, commercial, student/Ph.D
research, something else? We did sponsor some interesting projects before and
we plan to resume it with the new cameras starting this Fall.
Andrey
---- On Sun, 31 Jul 2016 23:29:40 -0700 Elham
Omrani<elh.omr...@yahoo.com> wrote ----
Dear Andrey,
Thank you for good guidance and suggestion. in your website, you have explained
that this camera can be develop by c++ and opencv is one of c++ libraries.
NC393-H camera is very expensive for me.
Sinserly
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.
Sinserly
Elham
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
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