1. A method of generating an image, the method comprising: capturing a first sub-image during a first exposure with a first pixel subset of an image sensor; capturing a second sub-image during a second exposure with a second pixel subset of the image sensor, the second exposure being longer than the first exposure; capturing a third sub-image during a third exposure with a third pixel subset of the image sensor, the third exposure longer than the second exposure; capturing a fourth sub-image during a fourth exposure with a fourth pixel subset of the image sensor, the fourth exposure longer than the third exposure, wherein the first, second, third, and fourth pixel subsets are disposed in a repeating pattern, and wherein the first, second, third, and fourth exposure periods start at a same initiation time; selecting a preferred exposure between the first, second, third and fourth exposures by analyzing the first, second, third, and fourth sub-images; capturing a full-resolution image at the preferred exposure, wherein the full-resolution image is captured by the first, second, third, and fourth pixel subsets simultaneously; and generating a final HDR output image based on the sub-images and the full-resolution image.