Support for the radial + tangential distortion model

[oleg-alexandrov]

Add support for the radial + tangential distortion model. This has 5 distortion coefficients, stored in order k1, k2, p1, p2, k3. The k1, k2, k3 coefficients are for radial distortion, and p1 and p2 for tangential distortion. This was validated with the OpenCV implementation using the function cv::projectPoints().

Corresponding code was added in "ale" (https://github.com/DOI-USGS/ale/pull/575).

The issue discussing this: https://github.com/DOI-USGS/usgscsm/issues/465

Tests were added for:

• Ensuring distortion and undistortion are inverse to each other
• Loading an ISD and running image-to-ground and ground-to-image operations, and saving a state file. The ISD was obtained from a DawnFC example by replacing the DawnFC distortion (which is only radial with one coefficient) by the larger set of distortion coefficients which just get appended to the existing coefficient.

Licensing

This project is mostly composed of free and unencumbered software released into the public domain, and we are unlikely to accept contributions that are not also released into the public domain. Somewhere near the top of each file should have these words:

This work is free and unencumbered software released into the public domain. In jurisdictions that recognize copyright laws, the author or authors of this software dedicate any and all copyright interest in the software to the public domain.

• [x] I dedicate any and all copyright interest in this software to the public domain. I make this dedication for the benefit of the public at large and to the detriment of my heirs and successors. I intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.

[oleg-alexandrov]

Any comments as to whether changing the name of an internal function is fine or it has to be kept consistent? The new name was motivated by the fact that there are now two distortion Jacobians, for transverse and radtan distortion.

BTW, I think the binary compatibility may have been broken just because the Distortion enum has one more field now.

Anyhow, this is the last issue for this pull request, so hoping to hear how to proceed.

[oleg-alexandrov]

@acpaquette: Any firm decision on this? No problem adjusting things either way, then it could be pulled in.

[oleg-alexandrov]

@acpaquette @jlaura: Thoughts? Happy to conform what is considered existing policy or best practices, if a specific change is suggested. There's no good reason for this to be left in limbo as people move on and stuff gets forgotten.

[oleg-alexandrov]

Thanks. Can this be pulled in? I haven't gotten yet the write access Jay applied for. Then I'll take care of such things without bugging folks.