make match ratio configurable in opencl/sift

[ChannyClaus]

resolves https://github.com/silx-kit/silx/issues/4098

allows the users to configure match ratio via the environment variable SILX_SIFT_MATCH_RATIO. should be a pretty low-risk + perfectly backwards compatible change.

[kif]

One should document this new environment variable ... beside this, the code LGTM

[t20100]

An environment variable doesn't seems to be needed here.

Since silx.opencl.sift.param.par is a dict, it is possible to change the value programmatically:

import silx.opencl.sift.param

silx.opencl.sift.param.par["MatchRatio"] = 0.5

[ChannyClaus]

An environment variable doesn't seems to be needed here.

Since silx.opencl.sift.param.par is a dict, it is possible to change the value programmatically:

import silx.opencl.sift.param

silx.opencl.sift.param.par["MatchRatio"] = 0.5

ahh darn great point. let me close this. thanks! should we document this?

[t20100]

should we document this?

Yes, Pull Request welcomed!