alignment of 3D stacks

Posted by rachelcjwang on Sep 28, 2010; 2:05am
URL: http://imagej.273.s1.nabble.com/alignment-of-3D-stacks-tp3686789.html

Hi everyone,

I am new for ImageJ. I tried to find similar posts for my questions, but I couldn't find answers.

I am trying to align two 3D stacks of bead files.  They were taken from the same field by two different cameras, so they are off a bit on x, y and z rotation, maybe axis orientation too.   I am using align3 TP. After I define ROIs in both images (one section of two stacks), and I click "match ROIs".  I got a results window saying

        java.lang.NullPointerException
        at align3tp. Alignment.setup (Alignment.java:331)
        at align3tp.Alignment.matchROIs(Alignment.java:1023)
        at align3tp.Alignment.doCommand(Alignment.java:220)
        at Align3_TP$RunOption.run(Align3_TP.java:243)

What does it mean?  How can I fix it? Thank you very much.
Rachel