System and method for optimizing focus of optical system passively

A system for optimizing focus of an optical system passively, comprising:

• at least one processing unit configured to implement a method for optimizing focus of an optical system passively, to receive image data from a sensor device, to send a desired focus distance to a control unit, and to receive a current position info from a control unit;
• wherein the method comprises the following steps:
• discretizing optical positions (focus distances) of the optical system with respect to precision requirements;
• initializing an idle counter to zero, the idle counter holds a number of iterations when the optical system is unable to improve focus performance;
• driving the optical system to a predetermined initial optical position;
• initializing a best position, the best position holds a best focusing distance came across up until a current execution iteration, to a current position;
• clearing a sharpness array, the sharpness array holds sharpness values of already processed images;
• calculating correspondence for at least one image in 2-tuple format using a focus distance and a sharpness value;
• adding at least one sharpness value to the sharpness array;
• calculating a longest increasing subsequence on the sharpness array;
• checking if a length of the longest increasing subsequence increases;
• clearing the idle counter if the length of the longest increasing subsequence increases;
• setting the best position to the current position;
• incrementing the idle counter if the length of the longest increasing subsequence doesn't increase;
• checking if a termination threshold is reached;
• checking if the current position corresponds to an end of discrete optical positions if the termination threshold is not reached;
• driving motors to a next position, if the current position doesn't correspond to the end of discrete optical positions;
• going to the best position and terminating the method, if the termination threshold is reached or if the current position corresponds to the end of discrete optical positions;
• at least one sensor device connected to the processing unit, and is configured to obtain an image data, and to pass the image data to the processing unit for analysis;
• at least one control unit connected to processing unit, and is configured to obtain a data regarding the desired focus distance from the processing unit, to drive motors of the optical system to obtain a focus at a specific distance;
• and to report a current focus distance to the processing unit;
• at least one motor unit connected to control unit, and is configured to modify the focus distance of the optical system according to commands of the control unit;
• at least one memory unit connected to processing unit, and is configured to store optimization results found by the processing unit.