Image focusing method and associated image sensor

• Main Author: FOWLER BOYD
• Format: Patent
• Language: Chinese; English
• Published: 03.03.2023
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

An autofocus method includes capturing an image of a scene with a camera including an array of pixels; calculating a horizontal difference image and a vertical difference image; and combining the horizontal difference image and the vertical difference image to obtain a combined image. The method further includes determining, from the combined image and the intensity image, an image distance relative to the camera lens at which the camera forms the in-focus image. The pixel array includes a pair of horizontally adjacent pixels and a pair of vertically adjacent pixels, each pixel pair being located below a respective microlens. For each pair of horizontally adjacent pixels, the level difference image includes a derived pixel value that is an incremental function of the difference between pixel values generated by the pair of horizontally adjacent pixels. For each vertically adjacent pixel pair, the vertical difference image includes a derived pixel value that is an incremental function of a difference between p