Patent ID: 6920235

Claim:
A method for determining angles of oblique and arched distortion of a textile fabric, with the use of at least one optical detector with axes of symmetry orientated with respect to the fabric, the method comprising: illuminating an area of the fabric with a light source; acquiring, in digital form, a real image of the area of the fabric, irrespectively of the orientation of the optical detector with respect to the fabric, wherein the fabric is illuminated for just the time necessary to acquire the image; rotating the image and compensating for the orientation of the axes of symmetry of the optical detector with respect to the fabric; applying to the image algorithms useful for increasing the reliability of the results of subsequent processing; applying a two-dimensional Fourier transformation to the image; calculating an angle of local distortion by analyzing the spectrum of the Fourier transformation; and calculating the angles of oblique and arched distortion, starting from the angle of local distortion.