Stereoscopic imaging platform with disparity and sharpness control automatic focusing mode

An apparatus for imaging a target site, the apparatus comprising:

• a stereoscopic camera configured to record a left image and a right image of the target site for producing at least one stereoscopic image of the target site;
• a controller in communication with the stereoscopic camera and having a processor and tangible, non-transitory memory on which instructions are recorded;
• wherein the stereoscopic camera includes a lens assembly having at least one lens and defining a working distance, the lens assembly having at least one focus motor adapted to move the at least one lens to selectively vary the working distance;
• wherein the controller is adapted to selectively execute one or more automatic focusing modes for the stereoscopic camera, the one or more automatic focusing modes including at least one of a disparity mode and a sharpness control mode;
• wherein the disparity mode and the sharpness control mode are adapted to rely on disparity feedback to change the working distance in order to achieve focus in the at least one stereoscopic image, the controller being configured to:
• determine a selected direction for moving the at least one focus motor;
• scan a range of the working distance in the selected direction;
• calculate a disparity signal at a plurality of steps in the range;
• command the at least one focus motor to a maximum sharpness position when the disparity signal is at or below an acceptable threshold;
• and
• command the at least one focus motor to a zero-disparity position when the disparity signal is above the acceptable threshold, the zero-disparity position corresponding to the disparity signal having a value of approximately zero.