An image sensing system includes a pixel array, an analog-to-digital converter circuit, and a memory. The pixel array includes a first pixel, a second pixel, and a third pixel interposed between the first pixel and the second pixel. During a first sensing time, the analog-to-digital converter circuit converts a first image signal received from the first pixel to first image data and converts a second image signal received from the second pixel to second image data. During a second sensing time, the analog-to-digital converter circuit converts a third image signal received from the third pixel to third image data. The first image data and the second image data are written in the memory during a first write time, and the third image data are written in the memory during a second write time.