Monitor apparatus for monitoring spatial region set by dividing monitor region

A monitor apparatus, comprising:

• a three-dimensional camera configured to capture a three-dimensional image in a first direction;
• and
• a processor configured to
• process an output signal of the three-dimensional camera,
• set a part of an image capturing region of the three-dimensional camera as a monitor region for a monitoring operation,
• divide the monitor region by a plurality of cutting planes radially extending from the three-dimensional camera serving as a start point, to set a plurality of spatial regions,
• set one spatial region of the plurality of spatial regions on one end of the monitor region in a second direction as a first spatial region, the second direction being perpendicular to the first direction, and
• set another spatial region of the plurality of spatial regions on the other end of the monitor region in the second direction as a second spatial region.