I’d like to ask you about the following two statements from your website:
According to this page of website, field of view of Orbbec Astra [Pro/S] depth sensors should be 60° horiz x 49.5° vert., but both Astra SDK and OpenNI2 return 58.6° x 45.6° FOV for depth stream. The difference is rather significant especially for vertical field of view. Who is correct here?
Orbbec is committed to putting developers and the creative coding community first. That’s why our Astra SDK is cross-platform and open source. Get the source on GitHub.
But we cannot find source code of implementation of C API in this repository. Looks like, it contains only source code of C+±wrappers around C API, but doesn’t contain implementation of C API itself. Where can we find source code of openni_sensor.dll and orbbec.dll, for example? (Or this statement from your website is just marketing trick?)
For the fields of view, 58.59 x 45.64 is correct for depth stream. The color stream has a larger field of view, but due to how OpenNI2 works both streams return the same field of view. If you want more specific details on this, please contact our support team info@orbbec3d.com.
But we cannot find source code of implementation of C API in this repository. Looks like, it contains only source code of C+±wrappers around C API, but doesn’t contain implementation of C API itself.
Look closer. The C API implementation is in astra_core, specifically, in astra.cpp which calls into the context and finally the context impl which does the real work.
Where can we find source code of openni_sensor.dll
If you’re looking for the latest changes for the Astra SDK 2.0 beta, just be aware that we have not pushed them yet. Not for any particular reason except that we’re running a million miles a minute to get to the final 2.0 release and have not had time to do a few minor housekeeping items to prepare the updated code for open source release. It will be the full commit history though. Except github to be updated when we post the final 2.0 release.
For the fields of view, 58.59 x 45.64 is correct for depth stream. The color stream has a larger field of view, but due to how OpenNI2 works both streams return the same field of view.
This makes sense, but we have two Orbbec Astra Pro and calibrated their color cameras in VGA mode. For the first item FOV is about 56.26 x 43.70, for the other - 56.8 x 44.15, which is less than FOV of depth sensor.
BTW, Astra SDK returns approx. 66.1° x 40.2° even for VGA mode, which is first of all not convenient (we have to recalculate this 16 : 9 FOV to 4 : 3 FOV); then it is not close to results of manual calibration (see above).
Look closer.
…
Thank you for pointing to these sources. This is really helpful. And sorry for my blindness.
We have it on our plan to audit the values like field of view and supported resolution modes for different sensors before we finalized the Astra SDK 2.0 release. We have added a lot of sensors and hardware revisions since we first release Astra SDK so it is possible that some scenarios or variations report incorrect data. Astra Pro has a 720p color sensor so its native field of view is larger than Astra and 16:9 but as you found in VGA it is different. Here I’ll have to disengage and suggest you email the support team info@orbbec3d.com to get specific help for your situation. They have all the data for different sensors and can give you definitive answers for your hardware.
The C API implementation is in astra_core, specifically, in