ObjectInfo and min/max Palette

[Manik]

Hi all,

I would like the user of my BrainVisa process to choose a threshold for an MRI, so I use the following method in my process :
- open the MRI in Anatomist
- popupPalette to open the palette window (by the way, the window appears outside the screen except for a small part of it)
- the user chooses the min value of the "DoubleThreshold" palette to see a certain pattern
- the user clicks "ok" on a small dialog box (opened with context.ask).
- the process reads mri.objectInfo()['palette']['min'], and gets a float value between 0 and 1.

The problem is that I am using an external program to process the MRI, which needs the "real" value of the min :
- if the MRI is expressed in unsigned 8 bits, I want the threshold to be between 0 and 256,
- if it is a signed 16 bits, I want it between -32000 and +32000...

Is there a way to get this value from anatomist (which displays it in the palette window), or should I check the type of data of the MRI and compute the right value for U8, S8, U16... ?

Thanks !

[riviere]

Hi Manik,

Palettes thresholds are normalized (generally between 0 and 1 but they can be outside these bounds), but ObjectInfo should also provide texture extrema information: there should be 'textureMin' and 'textureMax' properties. You just have to apply a scaling factor with these extrema (0 for palette means textureMin value, and 1 means textureMax) to get an absolute threshold.

Does it help ?
Denis

[Manik]

In fact, I just tried to use the 'palette' key, and I should have tried the 'texture' properties, as you said.
Everything works now !
Thanks,