Brickscanner photographs every pile from three directions: from the front, from the left and from the right. That helps a lot, because a brick that looks like another one from the front often gives itself away from an angle.
For that to work, though, the app has to know which brick on the left photo belongs to which one on the middle and the right photo. I built a new matching method for this: it compares appearance, position and colour, and makes sure two different bricks are never lumped together by mistake. A red and a blue brick, for example, can no longer count as the same one.