A method of detecting a flow in a sequence of images

A method of detecting a flow in a sequence of images of a material, the method comprising the steps of:

• providing a sequence of at least three images of an area of the material, each image including a plurality of voxels or regions of interest such that the at least three images of the area of the material provide for each voxel or region of interest an intensity I(t) as a function of time t for at least three points in time;
• Fourier transforming I(t) for each voxel or region of interest to obtain a distribution I(ω) of frequency co, I(t) including the intensities for the at least three points in time;
• and
• analysing I(ω) for each voxel or region of interest and generating a processed image of the area of the material including the voxels or regions of interest, comprising associating voxels or regions of interest that have a larger amplitude IL(ωH) at a frequency ωH in a higher frequency range than other voxels or regions of interest with a first visual property and voxels or regions of interest that have smaller amplitude IS(ωH) in the higher frequency range than other voxels or regions of interest with a second visual property;
• wherein the larger amplitude I(ωH) is associated with a flow and the smaller amplitude IS(ωH) is associated with a stationary region.