Method for correcting an image of at least one object presented at a distance in front of an imaging device and illuminated by a lighting system and an image pickup system for implementing said method

An image pickup system for delivering a corrected image of an image taken by an imaging device of an object presented at a distance in front of said imaging device, said object being illuminated by a lighting system, wherein the image pickup system comprises circuitry adapted for:

• estimating, from at least one image taken by a 3D image pickup apparatus, a 3D model of the object as it is at the time said imaging device takes an image,
• executing an image-simulation comprising calculating the light intensity of each point on a simulated image as it would be taken by the imaging device, using said 3D model estimated, a model of the illumination of the object by said lighting system, a model of reflection on a surface of an object and a model of said imaging device, in order to obtain a simulated image of said object, and
• determining points on the simulated image for which the light intensity is above a maximum threshold,
• determining points on the simulated image for which the light intensity is below a minimum threshold, the minimum threshold being different from the maximum threshold,
• correcting the image taken by said imaging device in order to modify the light intensity of each point on the image actually taken by the imaging device or on at least one area of interest of the image actually taken by the imaging device, according to the light intensity of the corresponding point in the simulated image or the respective light intensities of points adjacent to said corresponding point in the simulated image, the correcting comprising:
• calculating, for each point on the image or on at least one area of the image taken by said imaging device, a correction factor that is a decreasing function of the light intensity of the corresponding point in the simulated image of the said object, and
• modifying the light intensity of each point on the image or at least one area of the image actually taken by said imaging device in proportion to said correction factor,
• said correcting not being performed for the points on the image taken by the imaging device corresponding to the points on the simulated image thus determined.