technical docs :: roi format
The format of the ROI files is quite simple: text-based, space-delimitted with four columns. Each row of the ROI file corresponds to a particular voxel. The columns refer to:
- slice number of the voxel
- row coordinate of the voxel
- column coordinate of the voxel
- value at the voxel
Note that columns two and three refer to row and column values, not x and y values. Not keeping this distinction in mind will cause headaches down the road; trust me, Ive had them.
The fourth column, value, is normally 1, the exception being overlap ROIs, where the values denote the type of overlap at that voxel. I also reserve the right to use those values for other purposes in the future.
Planned later versions of the ROI format will require that the first line begin with the pound character, after which will describe the dimensions of the functional volume.