Abstract: A method for determining the angles of oblique and arched distortion in a textile fabric, with the use of at least one optical detector with axes of symmetry orienated with respect to the fabric, includes illuminating an area of the fabric with a light source. A real image of the area of the fabric is acquired in digital form, irrespectively of the orientation of the optical detector with regard to the fabric, wherein the fabric is illuminated for just the time necessary to acquire the image. The image is rotated and compensated for the orientation of the axes of the symmetry of the optical detector with regard to the fabric. Algorithms useful for the increasing the reliability of the results of subsequent processing are applied to the image, followed by a Fourier transformation. An angle of local distortion is calculated by analyzing the spectrum of the Fourier transformation and the angles of oblique and arched distortion are calculated starting from the angle of local distortion.

Abstract: This invention concerns a method for determining the angles of oblique and arched distortion in a textile fabric or similar, with the use of at least one optical detector. It consists of the acquisition, in digital form, of a real image of an area of the fabric or similar which is illuminated for just the time necessary to acquire the image; the possible rotation of the image; the storing of the image inside the optical detector; the application of appropriate algorithms to the image in order to increase the reliability of the results, and the determination of the angle of local distortion through analysis of the two-dimensional spectrum of the Fourier transformation, in order to calculate the distortion angles, starting from the angles of local distortion.