| 摘要 |
PURPOSE:To obtain a method for separating a heterogeneous part (nondefect) from a defect and detecting only the defect precisely in the case when a product itself, such as net-reinforced glass, contains the part of different light transmittance (metal wire) as a part of the product. CONSTITUTION:In regard to a filtering processing which is executed for a spectral component made to appear by converting an inputted value in space coordinatesinto a spectrum in a frequency region, a filtering processing which zeroes a position located at an integral multiple of the period of a periodical structure being a nondefect and also the spectral component in the vicinity thereof is executed and the spectrum formed as the result is converted into the value in the space coordinates. As for equipment, a fast Fourier transform(FFT) device, a filter for executing the filtering processing for the spectral component appearing at a certain determined position and an inverse fast Fourier transform(IFFT) device are employed. |
