OpenCV 2 or 1

[SirVer]

A __version__ function in the future is little help to distinguish
between OCV 1 and OCV 2. BUT the current case is not bearable; for
example the test suite can not be run when you have OpenCV 1
installed, because OpenCV errors always result in a coredump because
of their braindumped I-do-my-own-Exceptions-In-C-Which-Are-Uncatchable
Stuff. That is, as soon as the opencv tests run, the whole python
process is KILLED by opencv throwing an exception because I expects an
array of 1x5 instead of 1x4. (Note that the same is true if we do
stuff vice-versa: making version 1 a dependency and the user has 2
installed).

The only REAL solutions I see for this mess is to either
a) decide which version to build against at build time using IFDEFs.
Which is ugly and not easy to pull off and makes OpenCV a hard build
time dependency. On plus we would have to ship binary versions linked
against OCV1 and OCV2. Ugly code, Ugly distribution, hard to
implement.
b) Determine at run time if the user has OpenCV 1 installed and ABORT
then in a pythonic fashion. I know of no portable way to pull this
off; one could only check for relative positions of functions in the
binaries or so. Nice code, nice distribution, very hard to implement.
c) Rip the parts that we need from the OpenCV source code (if
licensing allows that) and build our own subset of the functionality
into scikit.image. No dependency on the OpenCV anymore, no cranky
void* pointer passing around, no strange exceptions that are
uncatchable. Heaven on earth. Downside: a lot of work. Upside: We
really would provide the image processing capabilities.

What do others think? Personally, I always wanted to have a better
designed Image Library with a smaller, but well tested subset of
ImageProcessing Algos that are really useful.


> Goodluck with getting that done though. I doubt we will see a new
> OpenCV release for awhile... and people will be using 2.0 for a long
> time to come...
No wonder; hacking OpenCV code is as ugly as coding can get.

Cheers,
Holger

>
> 2009/11/4 Stéfan van der Walt <ste... at sun.ac.za>:
>
>
>
>
>
> > 2009/11/4 Chris Colbert <sccolb... at gmail.com>:
>
> >> OpenCV has a ___version___ header file.
>
> > We can only access that if it exposed as a function, though, so maybe
> > they can help us out.
>
> > Cheers
> > Stéfan