Imaging system for granular material with homogeneous background

An imaging system (100) comprising:

• at least one camera (3),
• a pair of mirrors (2a, 2b),
• wherein the at least one camera (3) is directed towards the pair of mirrors (2a, 2b),
• wherein respective mirror surfaces of the mirrors in the pair of mirrors (2a, 2b) are angled from each other at an angle α and the mirrors (2a, 2b) are arranged with the respective mirror surfaces edge to edge with each other,
• wherein the imaging system (100) is intended for receiving a sample along a main axis (V) extending between the pair of mirrors, and
• a background element (4) formed as a cylinder portion with a cylinder axis deviating from the main axis,
• wherein said background element (4) comprises a surface directed towards the pair of mirrors (2a, 2b) and is placed within a field of view of the at least one camera (3) and an image to be taken by the at least one camera (3) through reflection in the pair of mirrors (2a, 2b), and
• wherein a division plane extends through the pair of mirrors and cuts straight through a position where the sample is being imaged by the at least one camera (3), substantially perpendicular to the main axis, where the at least one camera (3) is arranged on a first side of the division plane, and an entirety of the background element (4) is arranged on a second side of the division plane, and the at least one camera (3) is directed obliquely towards the position where the sample is being imaged so that no part of the at least one camera (3) itself is within the field of view of the at least one camera (3) and an image to be taken by the at least one camera (3) through reflection in the pair of mirrors (2a, 2b).