Method for automotive device to project image onto windshield for viewing by primary viewer

A method for an automotive device to project an image onto a windshield for viewing by a primary viewer, comprising:

• determining a primary viewer state;
• outputting a corresponding content correction signal and a corresponding gamma correction signal according to the primary viewer state;
• generating a corresponding display signal according to the corresponding content correction signal and the corresponding gamma correction signal;
• displaying the image according to the display signal;
• and
• projecting the image onto the windshield,
• wherein the primary viewer state is determined to be a driver viewing state or a front-seat passenger viewing state, and the front-seat passenger viewing state comprises a front-seat passenger average eye position,
• wherein the step of determining the primary viewer state comprises:
• taking a facial image of a front-seat passenger;
• analyzing the facial image of the front-seat passenger to generate a facial image signal of the front-seat passenger;
• and
• calculating the front-seat passenger average eye position within a second period according to the facial image signal of the front-seat passenger, wherein the second period is between 0.5 seconds and 3 seconds.