An image sensor, a camera module, and an electronic device are provided. The image sensor includes a pixel array and a control circuit. The pixel array includes a plurality of row pixels and a plurality of column pixels. The control circuit is configured to receive a first instruction to control an intersection region of a part of the plurality of row pixels and a part of the plurality of column pixels to detect an illumination intensity. The control circuit is further configured to receive a second instruction to control at least part of the pixel array to acquire an image.