Image subtraction of illumination artifacts

A method of removing an artifact resulting from an in-line illumination device of an imaging system from an image of an object to be analyzed, the imaging system including a camera, the method comprising:

• using a processor for obtaining a plurality of artifact images using respective artifact illumination levels from the in-line illumination device, the in-line illumination device introducing a light source between the camera and a plane of an object to be analyzed, and each artifact image being a specular image of the light source as specularly reflected back from one or more lens elements of the camera onto an image detector of the camera;
• imaging the object to be analyzed using the camera wherein the in-line illumination device is using an object illumination level;
• and
• using respective pixel values of at least one of the plurality of artifact images to adjust respective values of the object image on a pixel address-by-pixel address basis to obtain a corrected image of the object using the processor.