Origami Filter for Strioscopy

Origami Filter for Strioscopy. **Principle:** - Fourier filtering allows for the modification of 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, a purified one: this is why the Ovio Laser Torch (ref. 204 080), ready-to-use and pre-set, is ideal for this type of technique. **Results:** In the filtered image, it can be observed that the outlines of the features are highlighted. The contrast becomes generally the same inside the features (black) and in the background (white).