The invention relates to a system (100) for visualizing an image data set comprising a plurality of voxels, using a ray casting method, each voxel of the plurality of voxels belonging to at least one class, each class of the at least one class being associated with an intensity redistribution function for computing a redefined voxel value of a voxel from a measured voxel value of said voxel, the system comprising a sampling unit (120) for computing a sample value at a sample location on a projection ray cast from an image pixel, based on a redefined voxel value of at least one voxel proximal to the sample location on the projection ray, wherein the redefined voxel value of the at least one voxel is computed from a measured voxel value of the at least one voxel, using the intensity redistribution function associated with the at least one class of the at least one voxel.