Thank you very much Bob Cox, I am new to fMRI data processing and Im sorry if my question was vague. I will try to explain more details.
By voxel-wise analysis I mean that every single voxel should be considered as a ROI. you can find more details in
this article. As far as I know common approaches tend to find seed voxels or find the ROIs via atlases. But in this approach each single voxel is a ROI. What I need is to extract all these ROI signals(time series) for all these ROIs and put them in a matrix, so I can use hub detection or clustering algorithms to process them.
My teacher told me that some steps like smoothing should be handled carefully when each voxel is a ROI. To be honest we (me and my teacher) don't know much about fMRI data analysis but we are excited about the big data challenges that the voxel-wise approach brings.