Methods, systems and apparatuses for motion detection using auto-focus statistics

A method for detecting motion using an imager comprising:

• obtaining motion sensitive statistics data for a plurality of image frames, wherein each image frame comprises a plurality of corresponding windows;
• for each window, determining a relative difference value for a particular window using motion sensitive statistics data from first and second image frames;
• determining a motion score, wherein the motion score is a summation, for each window for which the relative difference value is greater than a first threshold, of a motion variable multiplied by a weight factor corresponding to each window;
• and
• determining if there is motion by comparing the value of the motion score to a second threshold.

An imaging system comprising:

• a lens;
• a pixel array for capturing image frames received through the lens;
• and
• an image processing circuit which is operable to detect motion in the captured image frames, wherein the motion detection comprises:
• obtaining motion sensitive statistics data for a plurality of image frames, wherein each image frame comprises a plurality of corresponding windows;
• for each window, determining a relative difference value for a particular window using motion sensitive statistics data from first and second image frames;
• determining a number of times the relative difference value is greater than a first threshold;
• and
• determining if there is motion by comparing the number of times the relative difference value is greater than the first threshold to a second threshold.

An imaging system comprising:

• a lens;
• a pixel array for capturing image frames received through the lens;
• and
• an image processing circuit which is operable to detect motion in the captured image frames, wherein the motion detection comprises:
• obtaining motion sensitive statistics data for a plurality of image frames, wherein each image frame comprises a plurality of corresponding windows;
• for each window, determining a relative difference value for a particular window using motion sensitive statistics data from first and second image frames;
• determining a motion score, wherein the motion score is a summation, for each window for which the relative difference value is greater than a first threshold, of a motion variable multiplied by a weight factor corresponding to each window;
• and
• determining if there is motion by comparing the value of the motion score to a second threshold.