PORTABLE ELECTRONIC DEVICE AND OPERATION METHOD

A portable electronic device and an operation method are provided. The portable electronic device includes a body, a screen, a camera, an image sensor and a main system. The image sensor continually captures a first image outside the body with a first resolution and a first power consumption. The camera is turned on in the first state of the portable electronic device by the main system to capture a second image outside the body with a second power consumption and a second resolution only when the face image information appeared for over two seconds on the screen is detected by the image sensor from the first image. The second resolution is higher than the first resolution, and the second power consumption is higher than the first power consumption.