complex-valued images in ImageJ2 ?

Posted by Adrian Daerr-2 on Sep 27, 2013; 1:44pm
URL: http://imagej.273.s1.nabble.com/complex-valued-images-in-ImageJ2-tp5004962.html

Hello,

For an image analysis which would benefit from using complex numbers
(Fourrier analysis etc), I downloaded ImageJ2 after I saw that imglib
defines promising ComplexTypes. However I do not manage to naively
create a complex-valued images in an ImageJ2 plugin. Should it be
possible ? Before I fall back to treating real and imaginary components
separately, I would like to know what the current status of complex type
images is in ImageJ2 (creation, processing, viewing ?)?

Some details about what I tried: after easily compiling the
GradientImage example from the simple-commands in the IJ2-doc at

http://developer.imagej.net/writing-imagej2-plugins

I tried to modify this plugin to create a ComplexDoubleType Img object,
using the first example of the ImgLib2 doc at:

http://fiji.sc/ImgLib2_-_Getting_Started

with a ComplexDoubleType in place of the UnsignedByteType and using the
generic ImgFactory instead of the ArrayImageFactory, namely

Img< ComplexDoubleType > img = new ImgFactory< ComplexDoubleType
 >().create( dims, new ComplexDoubleType() );

The plugin compiles and runs (at least up to the dialog asking for width
and height), but nothing happens:
- ImageJ does not automatically display this Img even if I declare it as
output parameter:
   @Parameter(type = ItemIO.OUTPUT) Img< ComplexDoubleType > img;
- I do not see anything either using:
   net.imglib2.img.display.imagej.ImageJFunctions.show( img );
- I see no errors (where do I have to look ?)

The complete source of my plugin-attempt is at
https://gitorious.org/phasegradientimage/phasegradientimage/source/233c74c7932e3d8e469e95e47b7e30cdf5bb7be1:PhaseGradientImage.java

(and can also be cloned as
[hidden email]:phasegradientimage/phasegradientimage.git
)

If ImageJ cannot yet display ComplexType images, but *can* do headless
stuff using imglib that's fine with me, but I am quite confused that I
do not see any errors at all, even if I do stuff that is not permissible
(such as, if I understand the API correctly, calling ArrayImageFactory
with a ComplexDoubleType (i.e. a non-NativeType) as argument). Where are
errors logged ?

Any help appreciated,
Adrian

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