Image sensor and operating method thereof

An image sensor includes: a pixel array including a plurality of pixels divided into a plurality of binning areas; a readout circuit configured to, from the plurality of binning areas, receive a plurality of pixel signals including a first sensing signal of first pixels and a second sensing signal of second pixels during a single frame period and output a first pixel value corresponding to the first pixels and a second pixel value corresponding to the second pixels based on the plurality of pixel signals; and an image signal processor configured to generate first image data based on a plurality of first pixel values corresponding to the plurality of binning areas, generate second image data based on a plurality of second pixel values corresponding to the plurality of binning areas, and generate output image data by merging the first image data with the second image data.