An image sensor can include a pixel array including a plurality of unit pixels and a row driver arranged in a matrix form that includes a plurality of rows and a plurality of columns. Respective ones of the unit pixels may convent an incident light to an electric signal and may store the electric signal. The row driver may sequentially scan the plurality of rows and may sequentially perform an electronic shutter operation and read-out operation. The electronic shutter operation may reset the stored electric signal in each unit pixel and the read-out operation may read-out the stored electric signal in each unit pixel. The electric shutter operation can include a preliminary shutter operation and a main shutter operation which are sequentially performed on one row. The row driver may overlap the main shutter operation on a first row and the preliminary shutter operation on a second row.