[GEM-dev] new pix_colordetect

[Ricardo Fabbri]

> i would go for [pix_colorclassify].
> if you agree and are willing to change the name in your branch, i'll
> import it as is.

I agree and have just renamed it and it compiles cleanly here. You can
fetch the changes in the same 'color' branch.

> - - it would be great if the user could modify those labels. e.g. [1 0 0]
> sounds like a great label for "red", but some weird user might chose to
> prefer [0.5 1 0.8].

That will come with a later contribution. I wrote a [pix_equal]
external which can change any pixels "equal" to some value within a
given cosed r & g & b range. I use it to separate the colors into
different images, change the color label, etc.

>
> it would also be nice to be able to parameterize the detection code, but
> i guess it is too fine tuned to the six given classes (so it would both
> complicate things from the dev's and the user's povs)
>

I guess we should go with the simple algorithm at first, then improve
it if needed. I noticed that even with very bad lighting conditions
and offset colorbalance, at least 2 or 3 colors work robustly, so this
should be useful without tweaking. The parameters have already been
tuned on a large database of exemplars. But, I agree, decreasing the
sensitivity to e.g. 'red' would be nice. I say we wait for further
demands and beta-testing prior to making the external more complex.

Thanks!

Ricardo Fabbri
labmacambira.sf.net