Image sensor

An image sensor comprising:

• a first pixel group configured to share a first conversion gain transistor, a first floating diffusion region, and a first selection transistor;
• a second pixel group disposed directly adjacent to the first pixel group in a first direction, the second pixel group being configured to share a second conversion gain transistor, a second floating diffusion region, and a second selection transistor;
• a third pixel group disposed directly adjacent to the first pixel group in a second direction perpendicular to the first direction, the third pixel group being configured to share a third conversion gain transistor, a third floating diffusion region, and a third selection transistor;
• and
• a fourth pixel group disposed directly adjacent to the third pixel group in the first direction, the fourth pixel group being configured to share a fourth conversion gain transistor, a fourth floating diffusion region, a fourth selection transistor,
• wherein the first pixel group shares a first color filter, the second pixel group shares a second color filter different from the first color filter, the third pixel group shares a third color filter, and the fourth pixel group shares a fourth color filter different from the third color filter,
• wherein the first selection transistor and the third selection transistor are connected to a first output line, and the second selection transistor and the fourth selection transistor are connected to a second output line different from the first output line, and
• wherein each of the first pixel group, the second pixel group, the third pixel group, and the fourth pixel group comprises 2×2 photoelectric conversion elements.