[IGSTK-Users] Viewer Problem due to TransformPhysicalPointToIndex

[Fucang Jia]

Hi, Patrick,

There is a problem due to TransformPhysicalPointToIndex function, which belongs to Bug# 738,
but it seems that this critial bug has not been fixed.

When I load IGSTK\Sandbox-Release-8\Testing\Data\E000192,
press the left mouse button on the sagittal view in FourViewsTrackingWithCT app continuously, 
then the index changes little bye one, when the index of sagittal viewer was changed to 0, I press the
mouse button onto the sagittal image, it says "Picked point outside image". I tracked this bug, 
and found that it is due to index round up problem.

For example, the origin is  -153.6640625,
the spacing is 0.671875
the physical coordinate is 16.3203
so the according index is 
(16.3203+153.6640625)/0.671875 = 252.9999813953,
it was truncated to 252. 

Then resliceImage function will change the orthogonal image slice. 

I also found this behaviour will occur when certain DICOM dataset is loaded. When I load other DICOM dataset,
the axial and coronal slice will have problem, but sagittal view does not change when mouse pressed. It is because 
that certain origin and spacing parameters trigger this problem.

Thanks!

Fucang
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