Yes NITRC NICE-SIGN NICE-SIGN is a nice sign of bias field correction (nonuniformity) in medical images. This tool is fast and efficient. Technical details can be found at http://zheng.vision.googlepages.com/biasCorrection_miccai09_Zheng.pdf NICE-SIGN MR, Hypertension http://www.nitrc.org/projects/nicesign/, http://www.nitrc.org/projects/nicesign/