1. A method for adaptive non-rigid registration of multiple measurement modes of a target body, comprising the steps of: receiving first data comprising a first plurality of measured values each associated with a plurality of coordinate values for spatial or temporal dimensions based on a first measurement mode of a target body; receiving second data comprising a second plurality of measured values each associated with a plurality of coordinate values for spatial or temporal dimensions based on a different second measurement mode of the target body; determining a coarse scale transformation to maximize a coarse scale similarity measure between the first data and the second data; sub-dividing the second data into a plurality of sub-regions each comprising a spatially or temporally contiguous subset of the second data; determining an adaptive bin size for a mutual histogram based on a sample distribution for each sub-region of the plurality of sub-regions; determining a fine scale similarity measure between the plurality of sub-regions and a plurality of corresponding portions of the first data based on the mutual histogram with the adaptive bin size; determining a plurality of fine scale transformations to maximize the fine scale similarity measure; and transforming the plurality of coordinate values for each measured value of the second data based on the plurality of fine scale transformations.