Method and device for detecting defects, such as stains, scratches and dust, on a film in order, in particular, to correct the said defects while the film is being digitized
First Claim
1. A method for detection and correction of surface defects on a film, comprising advancing the film through an optical assembly comprising, on one side of the film, at least two light sources having different wavelengths which illuminate the film in a narrow area thereof, and, on another side of the film, a lens which projects two images of the area illuminated by beams coming from the two sources onto two linear photosensitive elements which are adapted, respectively, to the wavelengths of the two sources, and comparing digital data delivered by the two photosensitive elements, a result of this comparison being used to perform the aforementioned detection and correction.
1 Assignment
0 Petitions
Accused Products
Abstract
A method of detecting defects, such as stains, scratches and dust, on a film in order, for example, to correct said defects while the film is being digitized, comprises advancing the film through an optical assembly comprising: on one side of the film, at least two sources of light having different wavelengths which illuminate the film in a narrow area thereof, and, on the other side of said film, a lens which projects the two images of the area illuminated by the beams from the two sources onto two linear photosensitive elements which are adapted, respectively, to the wavelengths of the two sources. Moreover, said method includes comparing the digital data delivered by the two detection elements, the result of said comparison being used to perform the aforementioned detection and correction.
-
Citations
9 Claims
- 1. A method for detection and correction of surface defects on a film, comprising advancing the film through an optical assembly comprising, on one side of the film, at least two light sources having different wavelengths which illuminate the film in a narrow area thereof, and, on another side of the film, a lens which projects two images of the area illuminated by beams coming from the two sources onto two linear photosensitive elements which are adapted, respectively, to the wavelengths of the two sources, and comparing digital data delivered by the two photosensitive elements, a result of this comparison being used to perform the aforementioned detection and correction.
Specification