Support unrectified image output in Zed X One Source

[dsconnol-impactai]

Underlying Issue

Our business needs a higher magnification lens to detect small objects as part of an inspection product. To do this, we are using the Zed X One camera with custom optics. This means that, by default, the zedxonesrc returns an unusable video stream, since the lens calibration parameters are not defined. While we have calibrated our lens using OpenCV, we were unable to determine the appropriate file format to pass into the current zedxonesrc (there is documentation for the depth cameras, but not the monocular camera).

While this is certainly a solvable issue, our lens does not actually introduce much distortion (due to the higher focal length). We've worked around the above issue internally by retrieving unrectified images in zedxonesrc. We thought other people might appreciate the same feature, so we're submitting a PR here in case the Stereolabs team feels the same.

Change Description

• Add a property with the name output-rectified-image with a default value of true such that the default plugin behaviour is unchanged.
• Add property set, get, defaults, and initialization as is standard practice for GStreamer
• Add a switch to retrieve the image type sl::VIEW::LEFT when requesting rectified images or sl::VIEW::LEFT_UNRECTIFIED if not.
• This has been tested on v4.2.5 of the SDK, because we want to deploy with the latest stable release. It should work equally well on v5.0 EA, but we do not have capacity internally to test that at this time.
• Add corresponding update to README file

Other Info

We would absolutely love a document on the appropriate formatting for the OpenCV calibration file for a Zed X One camera, if you have it available!