Saturday, October 07, 2006

LiveWire Segmentation Plugin for ImageJ Release 0.9.5

I've released a new version of the Livewire segmentation plug-in here
For the official page, check http://ivussnakes.sourceforge.net/

New features:

***Make sure you have ImageJ 1.37r or later and Java 1.5 ***

Works with color:
Now LiveWire is able to segment color images. This is done converting them to grayscale and then using the standard procedure (Thanks, Volker Bäcker!)

Run with macro: one can now use the following macro to use LiveWire
run ("LiveWire", "x0=50 y0=30 x1=95 y1=95 magnitude=43 direction=13 exponential=30 power=10");

Just go to Plugins->Macro->Record...
Then type the above macro, give it a name and press the "Create" button.
Now save the file and go to Plugins->Macro->Install... Then, choose the macro file you've just created.
There'll be a new menu under Plugins->Macro->"Your New Menu". Choose it to run the Macro.
Make sure you've set the points inside the picture :)

New cost feature: Exponential
Now a new feature was added to cost. Basically, it gives more weight to paths that are over a low cost resultant gradient and paths over high gradients have less weight, being cheaper paths. This is done through the function:
fe = Math.exp(-pw*x)*fg;
where fe is the exponential cost and pw is the power parameter. Fg stands for the gradient magnitude cost (the one whose weight is affected by the "Magnitude" slider)
It works better if the other weights are set to zero (except for the "Power" one).

Better user interface:
Following code and opinions given by Volker Bäcker, the user interface is now better, so that the user is now able to finish segmentation through right-click and start another with left-click. To move points or add new points to the existing one, the user should press the keyboard shift key at the same time.

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