Filter mixed letters A and B

Filter mixed letters A and B. Principle: - Fourier filtering allows to modify certain undesirable frequencies of an object by inserting a suitable mask in the Fourier plane (or the focusing plane of the initial image). - Thus, the image (or the different spatial frequencies that constitute it) is interpreted as a diffraction pattern. These measurements therefore require a collimated light source, but above all purified: this is why the Ovio Laser Torch (ref. 204 080), ready to use and pre-set, is ideal for this type of technique. Results: Shape recognition: the letter a or the letter b can be highlighted depending on the direction of the opening of the filter slit.