An image sensor is provided. The image sensor includes: a pixel array of pixels arranged in a row and column directions. A first pixel provided in a first row of the pixel array includes a first sub-pixel connected with a first metal line, a second sub-pixel connected with a second metal line, a third sub-pixel connected with a third metal line, and a fourth sub-pixel connected with a fourth metal line. When a read-out operation is performed on the first pixel, signals applied to the first through fourth metal lines are sequentially enabled. Based on the applied signals, at least a part of charges accumulated in the first through fourth sub-pixels is diffused to a first floating diffusion node. The first sub-pixel and the third sub-pixel are adjacent in the column direction, and the first sub-pixel and the second sub-pixel are adjacent in the row direction.