RTK support

Since ASTRA does not support FDK except in very simple gemetries (practically only theoretical ones), we need to get this from somewhere else, at Elekta we use RTK, so I'll see if we can get that implemented.

RTK uses explicit projection matrices (per angle), right? Or can the matrix type be implemented in an operator-like fashion? Anyway, would be good to have support for this.

RTK has several geometry descriptions, the most general one is given by projection matrices per angle (I think). They at least have one geometry that matches our circular flat.

Is this still something of interest? If not, or if there's no chance of doing this in the somewhat near future, I suggest we close this.

Is this still something of interest? If not, or if there's no chance of doing this in the somewhat near future, I suggest we close this.

I think this is definitely of interest, especially since ASTRA does not easily run on MacOS X. I was thinking of issuing this as a MSc thesis topic. What is the harm of keeping this as an issue? On the other hand, it should go in under future development plans, if there is any such section.

I agree, this is of interest. But I'll wait until a proper use-case shows up until I do it, but perhaps someone else needs it.

What is the harm of keeping this as an issue?

Not much except issue spam.

On the other hand, it should go in under future development plans, if there is any such section.

That's what issues are for.

I think this is definitely of interest, especially since ASTRA does not easily run on MacOS X.

Willem-Jan is currently making conda builds for Mac, and there will be tests for Macs with CUDA. So that problem is gonna go away with the next release.

I was thinking of issuing this as a MSc thesis topic.

Ok, great.

What is the harm of keeping this as an issue?

No real harm, I was just going through all our ancient issues to check which ones are still relevant. Looks kind of bad to have tons of old open issues.

On the other hand, it should go in under future development plans, if there is any such section.

In that sense, this is the right place.

Willem-Jan is currently making conda builds for Mac

Actually they're already up on his conda channel.

I think the main issue is that barely anyone has a GPU on his Mac OS computer. A more long-term solution would be if someone implemented a cpu based backend that does not suck like scikit..

RTK v.1.4 now supports (http://www.openrtk.org/RTK/news/201802_release1.4.php) curved detectors (cylindrical). We should maybe consider this as an alternative backend to ASTRA, which is especially relevant for clinical CT applications.