| 摘要 |
PROBLEM TO BE SOLVED: To enable the determination of which paper among a database the paper has a high degree of similarity with by subjecting the image of the paper to frequency analysis and identifying the characteristics of a predetermined wavelength range, for example, a wavelength range including periodic components derived from paper manufacturing processes. SOLUTION: In a image pickup part 2, image data is obtained form light transmitted through or reflected by at least part of a paper sample and is subjected to frequency analysis at a frequency analyzing part 18. Integration data on each of a plurality of wavelength ranges from the data after the frequency analysis is obtained. The correlation of the integration data is obtained to the corresponding integration data of the same wavelength range of a contrast standard paper sample to determine whether the sample paper is identical to the standard paper sample.
|
