Image Analysis Tools to Quantify Visual Properties of Hair Fiber Assemblies 318 relaxer treatment (b and c). Visual observation clearly reveals the change in fiber curvature when comparing untreated hair with partially (b) and fully (c) relaxed hair. The corresponding two-dimensional Fourier transform images are shown adjacent to the original images of hair and provide us with a measure of fiber alignment. In the case of untreated African hair, there is no directionality apparent in the transformed image. The Fourier transform distribution is omnidirectional. However, when we examine the partially relaxed hair sample, a more narrow Figure 10. Images and their corresponding two-dimensional Fourier transform for (a) untreated African hair and the same hair type that underwent a (b) partial and (c) full chemical relaxation procedure.