Multiple #@matrix parameters not supported

[imagejan]

In a Matlab script started from ImageJ's script editor, a single #@matrix parameter works as expected and takes the current active image from ImageJ.

In analogy to #@ Dataset, I'd expect to get dropdown choice widgets for my parameters if I have more than one of them:

#@ matrix input1
#@ matrix input2

Instead, this show an error that a MatlabNumericArray is required but none is available.

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While MATLABNumericArrayPreprocessor (extends SingleInputPreprocessor) deals with the former case, the latter currently doesn't work presumably because there is no direct conversion support for ImagePlus -> MatlabNumericArray.

We could add support for all the common image-type objects (e.g. ImagePlus, Img, Dataset) by chained conversion using a delegate converter, but is this repository the right place to e.g. also contain the legacy ij.ImagePlus <-> matlabcontrol.extensions.MatlabNumericArray? @ctrueden?

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As an aside: the #@matrix script parameter alias is added in scripting-matlab by DefaultMATLABService