When I load an exported texture file (*.tex), the values are not in the original range anymore.
Do you know what is going on and how to prevent this automatic rescaling?
Thank you very much,
Nicolas.
Texture exportation: values range lost
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Olivier Coulon
- Posts: 176
- Joined: Fri Feb 27, 2004 11:48 am
- Location: MeCA research group, Institut de Neurosciences de La Timone, Marseille, France
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Hi Nicolas,
a texture generated by Anatomist (I supposed you fusioned a volume with a mesh or something like that) is rescaled between 0 and 1 (I think) because of the OpenGL mechanism used to create the texture. I don't think there is anything you can do about it, Denis can correct me if I'm wrong...
Two observations though :
- you can write a program that does the rescaling if you know the original range...
- are you trying to map functional data on a surface ? If yes, there is somebody working on that particular asect of things here, so hopefully there will be something available within a few months (which is probably too long to wait for in your situation).
Good luck,
Olivier
a texture generated by Anatomist (I supposed you fusioned a volume with a mesh or something like that) is rescaled between 0 and 1 (I think) because of the OpenGL mechanism used to create the texture. I don't think there is anything you can do about it, Denis can correct me if I'm wrong...
Two observations though :
- you can write a program that does the rescaling if you know the original range...
- are you trying to map functional data on a surface ? If yes, there is somebody working on that particular asect of things here, so hopefully there will be something available within a few months (which is probably too long to wait for in your situation).
Good luck,
Olivier
Olivier Coulon
Institut de Neurosciences de La Timone,
Aix-Marseille Université,
Marseille, france
https://meca-brain.org
Institut de Neurosciences de La Timone,
Aix-Marseille Université,
Marseille, france
https://meca-brain.org
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NicolasW
- Posts: 29
- Joined: Fri Mar 05, 2004 11:45 am
- Location: INRIA Sophia Antipolis, France
- Contact:
Hi Olivier,
thank you for your answer.
Actually, the final texture is not rescaled between 0 and 1:
For instance, I start from 3D data between [-3.2;+3.14] and the saved texture values are between 20.29 and 26.61, so there is at least a strange translation (and apparently not here but perhaps sometimes also a scaling) of the original values. Besides, this translation is not constant across the different textures.
I can indeed write a small program to correct this, but:
- it would imply to find a trick to estimate this varying translation and possible scaling parameters (for instance being sure to have a 0 value in node 1 of the mesh and a 1 in node 2), which prevents a more global use of the program.
- I wonder the origin of this problem
For your second point, you are right, a few months should (hopefully!) be too long for me.
Thanks,
Nicolas.
thank you for your answer.
Actually, the final texture is not rescaled between 0 and 1:
For instance, I start from 3D data between [-3.2;+3.14] and the saved texture values are between 20.29 and 26.61, so there is at least a strange translation (and apparently not here but perhaps sometimes also a scaling) of the original values. Besides, this translation is not constant across the different textures.
I can indeed write a small program to correct this, but:
- it would imply to find a trick to estimate this varying translation and possible scaling parameters (for instance being sure to have a 0 value in node 1 of the mesh and a 1 in node 2), which prevents a more global use of the program.
- I wonder the origin of this problem
For your second point, you are right, a few months should (hopefully!) be too long for me.
Thanks,
Nicolas.
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riviere
- Site Admin
- Posts: 1361
- Joined: Tue Jan 06, 2004 12:21 pm
- Location: CEA NeuroSpin, Saint Aubin, France
- Contact:
Hi,
The exported texture range used to be rescaled between 0 and 1 in previous anatomist versions, but this has changed, and in anatomist 3 the range should be preserved. If it's not what you get, then it's perhaps a bug, but it seems to work for me. What kind of texture have you exported ? A 3D fusion (volume+mesh) ?
Denis
The exported texture range used to be rescaled between 0 and 1 in previous anatomist versions, but this has changed, and in anatomist 3 the range should be preserved. If it's not what you get, then it's perhaps a bug, but it seems to work for me. What kind of texture have you exported ? A 3D fusion (volume+mesh) ?
Denis
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NicolasW
- Posts: 29
- Joined: Fri Mar 05, 2004 11:45 am
- Location: INRIA Sophia Antipolis, France
- Contact:
Hi Denis,
yes, it is a 3D fusion texture done with anatomist 3.0.0, implying a mesh at the format *.tri and an analyze format 3D image. I tried with another SPM T-map and this rescaling happened again, with another translation value.
I can send you the mesh and a T-map if you want to try with my data?
Nicolas.
yes, it is a 3D fusion texture done with anatomist 3.0.0, implying a mesh at the format *.tri and an analyze format 3D image. I tried with another SPM T-map and this rescaling happened again, with another translation value.
I can send you the mesh and a T-map if you want to try with my data?
Nicolas.