physical z displayed wrong when nz=1,nf>1

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physical z displayed wrong when nz=1,nf>1

Fred Damen

With a hyperstack (NZ=1,NF>1) and the Calibration.zOrigin and
Calibration.pixelDepth set correctly, and the sole scrollbar(which is
prefaced with a forward triangle) set to the leftmost position, the status
line on the main window displays the correct z physical location when
moving the cursor within the image/dataset window. Stepping this scrollbar
to the next position and then placing the cursor within the image window,
the status bar presents a computed z physical location that is one
pixelDepth away, even though this is at the same physical location as the
previously displayed image - the frame is different and has nothing to do
with physical location.

In MRI the voxel depth (in MRI lingo slice thickness) is not necessarily
the same as the physical distance to the same relative z location in the
next image in the dataset, i.e., it is common to have a gap in between
slices.  Each image will be tagged with its z location and if
Calibration.zOrigin is set for each slice it should be used instead of
computing the physical z location to display.

To reproduce you can create a hyperstack (NZ=1,NF=6) and use
Image>Properties... to set Origin 0,0,10 and pixel width second column to
"mm" and voxel depth to 1, then go to the second image and the physical z
location will displayed as 9 and not 10 as it should.

Image>Properties... does not display the z voxel offset for an image with
NZ=1, albeit will let you set this value.

Image>Show Info... and the image window's status bar obfuscates the fact
that there is a single slice with multiple frames.

Thanks in advance,


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