An image reading apparatus, a method of controlling the same, and an image forming apparatus including the same are disclosed. The image reading apparatus may pre-recognize performances of even-pixel and odd-pixel groups for each color in an image sensor including an even-pixel group and an odd-pixel group for each color. In case of reading an image using only one of the above pixel groups, the image reading apparatus may read the image using a superior-performance pixel group selected from the above pixel groups, such that a signal-to-noise ratio (SNR) may be reduced and image processing may be more quickly carried out.