[ros-users] Digital Camera 1394 in ROS?

[Patrick Beeson]

FYI,

I have my own ROS node that combines cameradc1394 with the Player 1394 
driver.  It works very reliably and depends on nothing but sensor_msgs 
(I have to say that I do not like having to download the kitchen sink 
just to get a simple hardware driver working, which is why I have my own 
versions of Swissranger 4K driver, 1394 camera, etc.).

Jack has been using it, along with a visualization tool I forked from 
somewhere.  I think I'll work with Jack to get this added to his ROS 
repository, or start my own (I'm assuming a reliable Swissranger 4000 
driver would be of desire to someone out there).  But, I should go ahead 
and make it start using the image_transport package.  So, it'll probably 
be a few weeks before this shows up in the ROS package browse.




Jack O'Quin wrote:
> On Wed, Mar 10, 2010 at 9:29 AM, Rosen Diankov <rosen.diankov at gmail.com> wrote:
>> I'm sorry you've been having so many problems with cameradc1394,
>> perhaps we can come up with a solution that will work well for you.
> 
> Thanks, Rosen.
> 
> I do not mean to come across as harshly critical of cameradc1394. I
> appreciate the work that has gone into it, and want to make it more
> accessible to users. We are trying to get undergraduates working
> productively with ROS vision components. Many of them are unfamiliar
> with both ROS and Linux. They will have a lot more trouble getting
> this working than I did.
> 
>> - You say it seems to work but not easy to install? Typing 'rosmake
>> cameradc1394'  should make and install everything for you, so are you
>> having trouble compiling things?
> 
> I did get it to work. It just took me a couple of hours. See below...
> 
>> - i think the libdc1394v2 package is for systems that do not have
>> libdc1394 version 2 installed, otherwise the library itself should be
>> stable.
> 
> On a recent boxturtle ROS install, the rosmake will fail because
> cameradc1394 depends on libdc1394v2, which is no longer being
> distributed. So, users either have to edit your manifest.xml to remove
> that dependency (which is still needed on Ubuntu Hardy), or they have
> to find and install the SVN repository for the
> camera_drivers_experimental package (doable, but not trivial).
> 
>> - cameradc1394 links the the ROS image libraries in order to
>> serialize/convert the message correctly, display the image, and
>> undistort it (radial distortion). You can disable the display
>> dynamically, so the the only other place where opencv would be used is
>> for undistortion and sending messages. Fortunately, both of these are
>> not that heavy on computation, so your system should handle it.
> 
> I am not particularly worried about computational overhead. It's more
> a question of system design and consistency.
> 
> The other ROS camera drivers do not depend on opencv2. There are
> higher-level packages, such as image_view for that sort of function.
> I'd prefer a simple DC1394 driver that behaves like the other ROS
> camera packages. That way people can work consistently with all those
> devices.
> 
>> - i'm pretty sure the svn checkout command on sourceforge points to
>> the correct code:
>> svn co https://cmu-ros-pkg.svn.sourceforge.net/svnroot/cmu-ros-pkg cmu-ros-pkg
>>
>> The 'trunk' folder might be making things a little confusing for you,
>> therefore i recommend:
>>
>> svn co https://cmu-ros-pkg.svn.sourceforge.net/svnroot/cmu-ros-pkg/trunk
>> cmu-ros-pkg
> 
> As you say, that is the correct URL for checkout. This error is
> currently not important, because you have no other branches (so far).
> But, you would not want users accidentally checking out *all* the
> branches instead of just the mainline version. When there is a stable
> version, they should check out branches/latest, instead, I suppose.
> 
>> - There is a link on the ros.org camera_drivers webpage
>> (http://www.ros.org/wiki/camera_drivers) into the correct wiki
>> location where the cameradc1394 webpage is stored. I'm not sure why
>> you feel it is hard to locate.....
> 
> It would be easier to find under http://ros.org/wiki/cameradc1394
> (which does not exist). It was hard to find because the SourceForge
> page for cmu-ros-pkg does not point to it. I did eventually find a
> pointer to it at the bottom of http://ros.org/wiki/libdc1394v2 (which
> does exist).
> 
>> - the README in the top source directory was old and contained nothing
>> useful, i just deleted it
> 
> Good idea, thanks.
> 
>> - I think you are the first person that has expressed dissatisfaction
>> with the way cameradc1394 is structured (no code reviews, etc), I've
>> tried to stick with the camera API willowgarage publishes as much as
>> possible. In the past year, it has been hard to keep up with it due to
>> many changes, but we're actively maintaining cameradc1394. For
>> example, I just noticed that the API requires a "set_camera_info" and
>> "request_image" services, which we will add as soon as we have time.
> 
> I fully understand the difficulty of tracking rapidly changing
> interfaces in a complex system. That is why I favor better integration
> into the ROS development process.  I believe a design review would
> have identified the inconsistencies between cameradc1394 and the other
> ROS camera drivers.
> 
> A good review might have caught the set_camera_info change, as well. I
> have so far been unable to display 1394 camera images with rviz. That
> may be the reason.
> 
>> If it makes a big difference for your team that the cameradc1394
>> resided on WillowGarage's servers rather than sourceforge's, then I'm
>> sure WillowGarage would be happy to host it.
> 
> I expect they would. I don't see the repo location as a problem right
> now (as long as the checkout URL is correct and up to date).
> 
> I believe including good documentation into the ros.org wiki would
> make the package much more accessible to beginning users. I am willing
> to assist, if you feel that would be helpful. I don't know much about
> digital cameras, but I do know how to edit the wiki. :-)
> 
> Regards,