Method and apparatus for intelligent ranging via image subtraction

A method for ranging comprising:

• illuminating a field of view with an illumination signal, which field of view potentially includes an object;
• synchronously receiving reflected signals from the field of view with illumination and absence of illumination of the field of view;
• capturing one of a first image and a second image within an array while the other one of the second image and the first image is still captured in the array, wherein the first image includes reflected signals from the field of view with illumination and the second image includes reflected signals in the absence of illumination, wherein the array is a pixel array and wherein capturing one of the first image and the second image of the array comprises
• capturing said first and second images in the pixel array in which said pixels of said pixel array are organized into a two dimensional array comprising pixel lines forming a first and second groups of pixel lines, said first group of pixel lines being unmasked and said second group of pixel lines being masked to prevent loading of imaged data therein, and wherein a first exposure of said pixel array a circuit loads said first group of pixel lines with said one of the first image and the second image, then shifts said one of the first image and the second image into said second group of pixels, and wherein a second exposure of said pixel array said circuit loads said first group of pixel lines with the other one of the second image and the first image, and then shifts said second image into said second group of pixel lines, said second set of pixel lines then storing said first and second images;
• and
• generating a subtraction image of at least a portion of said field of view comprising the pixel difference between said first and second images captured in said array.

A program storage device, readable by a computer, tangibly at least one program of instructions executable by the computer to perform method ranging, the method steps comprising the steps of:

• illuminating a field of view with an illumination signal, which field of view potentially includes an object;
• synchronously receiving reflected signals from the field of view with illumination and absence of illumination of the field of view;
• capturing one of a first image and a second image within an array while the other one of the second image and the first image is still captured in the array, wherein the first image includes reflected signals from the field of view with illumination and the second image includes reflected signals in the absence of illumination, wherein capturing one of the first image and the second image of the array comprises
• capturing said first and second images in an imaging pixel array in which said pixels of said array are organized into a two dimensional array comprising pixel lines forming a first and second groups of pixel lines, said first group of pixel lines being unmasked and said second group of pixel lines being masked to prevent loading of imaged data therein, and wherein a first exposure of said pixel array a circuit loads said first group of pixel lines with said one of the first image and the second image, then shifts said one of the first image and the second image into said second group of pixels, and wherein a second exposure of said pixel array said circuit loads said first group of pixel lines with the other one of the second image and the first image, and then shifts said second image into said second group of pixel lines, said second set of pixel lines then storing said first and second images;
• and
• generating a subtraction image of at least a portion of said field of view comprising the pixel difference between said first and second images captured in said array.