1. A pixel array of an image sensor, the pixel array comprising: a plurality of pixel groups, each pixel group comprising: one or more long exposure pixels; and one or more short exposure pixels, wherein each pixel group includes, from among the one or more long exposure pixels and the one or more short exposure pixels, a first pixel having a white component, a second pixel having a first color component, a third pixel having a second color component and a fourth pixel having a third color component, and the white component, the first color component, the second color component and the third color component are different from each other, wherein the first pixel belonging to a first pixel group, among the plurality of pixel groups, is a long exposure pixel, and the first pixel belonging to a second pixel group that is adjacent to the first pixel group, among the plurality of pixel groups, is a short exposure pixel, wherein the first, second, third and fourth pixels of each pixel group are arranged in a 2×2 matrix of two rows and two columns, wherein the plurality of pixel groups are arranged along m rows and n columns, where m and n are integers equal to or greater than 3, and wherein the first pixel belonging to a pixel group along a first row and a first column, among the plurality of pixel groups, the first pixel belonging to a pixel group along the first row and a third column, among the plurality of pixel groups, the first pixel belonging to a pixel group along a third row and the first column, among the plurality of pixel groups, and the first pixel belonging to a pixel group along the third row and the third column, among the plurality of pixel groups, are electrically connected to each other in a low resolution mode.