Method of image fusion on camera device equipped with multiple cameras

A camera device is provided. The camera device includes: a first imaging section, a second imaging section, a third imaging section, and a processor. The first imaging section, second imaging section, and third imaging section capture a first image, a second image, and a third image of a scene with a first field of view (FOV), a second FOV, and a third FOV. The processor is configured to generate a first output image by performing a first image-fusion process on the first image, the second image, and a third image in response to a zooming factor of the camera device being between a first zooming factor and a second zooming factor, wherein the first FOV is wider than the second FOV, and the second FOV is wider than the third FOV, and the second zooming factor is greater than the first zooming factor.