Methods and apparatus for autofocus for image capture systems

An apparatus to control autofocus, the apparatus comprising:

• at least one memory;
• machine readable instructions;
• and
• processor circuitry to at least one of instantiate or execute the machine readable instructions to:
• obtain face information including a current face region from a face detection library;
• calculate a region difference metric between the current face region and a reference face region;
• extract statistics of the current face region;
• control at least one of a scene change judgement or a dead zone to determine whether to trigger autofocus iterations;
• perform an autofocus iteration with lens movement controlled based on the region difference metric;
• and
• save an in-focus face region resulting from the autofocus iteration as the reference face region.

A method to control autofocus, the method comprising:

• obtaining face information including a current face region from a face detection library;
• calculating, via execution of instructions by a programmable circuit, a region difference metric between the current face region and a reference face region;
• extracting statistics of the current face region;
• controlling at least one of a scene change judgement or a dead zone to determine whether to trigger autofocus iterations;
• performing an autofocus iteration with lens movement controlled based on the region difference metric;
• and
• saving an in-focus face region resulting from the autofocus iteration as the reference face region.