Image processing device and method for sensing moving objects and rangefinder employing the same

An image processing device for detecting a moving object in a field of view comprising:

• a) a video camera for detecting sequential video data comprising a consecutive series of video frames of the field of view;
• b) a memory, coupled to said video camera, for storing sequential video data;
• c) means, coupled to said memory, for generating a standard image from the sequential video data comprising a consecutive series of video frames including,
• i) means for storing in said memory consecutive video frames captured at a predetermined sampling rate over a predetermined time interval, and
• ii) means for generating video data for a standard image by averaging the consecutive video frames for the predetermined time interval stored in the memory to obtain a composite standard image for the predetermined time interval;
• and
• d) subtraction means for subtracting the video data for said standard image from video data for a current video data frame to detect a moving object in the field of view.

A rangefinder for measuring a moving object in a field of view comprising:

• a) a first video camera for generating video data from images of objects which move in a first field of view, said first video camera having a variable magnification and an optical axis which is oriented towards the first field of view;
• b) a second video camera for generating video data from images of objects which move in a second field of view, with the second video camera being mounted at a predetermined distance from the first video camera, said second video camera having a variable magnification and an optical axis which is oriented substantially parallel with the optical axis of the first video camera and having a second field of view which has a region of overlap with the first field of view of the first video camera;
• and
• c) distance calculation means for calculating a distance to a moving object in the first and second fields of view of the first and second video cameras from the generated video data from the first and second video cameras.