Method and camera arrangement for measuring a movement of a person

A camera arrangement for measuring a movement of a person, wherein the camera arrangement comprises a camera and is arranged to repeatedly:

• determine at least one distance between at least one area on said person and corresponding pixels in the camera based on light received from said at least one area;
• wherein
• the camera arrangement is adapted to:
• receive different signal strengths between said corresponding pixels in the camera and pixels in the vicinity of said corresponding pixels so that at least some of said corresponding pixels and said pixels in the vicinity of said corresponding pixels are neither over- nor underexposed, and
• base said determining of said at least one distance on at least some of said corresponding pixels and said pixels in the vicinity of said corresponding pixels which are neither over- nor underexposed, and
• wherein the camera arrangement further comprises a defocusing arrangement, the defocusing arrangement being adapted to defocus light received by said camera to distribute light in multiple directions, so that different signal strengths between said corresponding pixels in said camera and pixels in the vicinity of said corresponding pixels are received so that at least some of said different signal strengths do neither relate to over- nor to underexposure.