1. A computer-implemented process for blending image regions, comprising using a computer to perform the following process actions: associating a separate offset map with each image region being blended; representing each offset map using a separate low-dimensional spline; for each separate low-dimensional spline, establishing an energy function equation comprising the summation of a set of terms comprising a separate term defining the difference in blended values of spline control points for each seam pixel and a separate term for each image region defining the blended values of the spline control points for each region, to produce a system of equations, wherein a seam pixel is a pixel whose location corresponds to the boundary between two adjacent image regions; solving the system of equations for the spline control point values that minimize the sum of all the terms; computing a correction term for each pixel in each image region based on the spline control point values exhibited at spline control points and a prescribed 2D tensor product spline basis; and applying the correction term associated with each pixel to that pixel to produce a blended image from the image regions.