BFC Correction Tool
The BFC correction tool is a graphical user interface for manually correcting the bias field in the MRI images.The tool allows users to manually select points corresponding to gray matter, white matter and CSF. Then, the bias field is corrected by finding a smooth scaling function such that the selected points are at approximately median intensity of the corresponding tissue types.
To install the BFC correction tool, you need matlab MCR for R2012a which can be downloaded from
Here are the step by step instuctions for downloading and using the BFC correction tool.
1. Download the tool Win64, MACi64
2. unzip the files into a folder.
3. In Windows, double click on gui_bias_correct.exe. In MAC, from the terminal, run gui_bias_correct.sh. This step will open file selection menu. Open the BrainSuite generated fname.bfc.nii.gz file to be corrected. This will open the user interface as shown below.
4. In the interface, find a region by scrolling through slices where you want to correct the bias field. In this region, select a point using the crosshair and press the tissue type button (WM, GM or CSF). Repeat this to select a few points (4-5) in different regions of bias field issues.
5. When you are done selecting the points, press Corr Bias button. This will perform the bias field correction. This step may take 2-3 min. Once it is done, it will open a window to show the corrected image and the bias field that corrects the image.
6. The corrected image will be saved in the same directory as the original image with the file name fname.corr.nii.gz.The bias filed estimated will also be saved in the same directory with the file name and extension fname.bias.nii.gz.
7. Close the gui. You can now open the corrected image in BrainSuite and redo the BFC to correct the small bias field issue that were left uncorrected, and proceed with rest of the BrainSuite sequence.
Please direct your questions and comments to Anand A Joshi ( firstname.lastname@example.org ).