The present disclosure provides a display apparatus including: a display; a signal receiver configured to receive an image signal; a signal processor configured to process the image signal received in the signal receiver; a first sensor configured to sense ambient brightness; and a controller configured to control the signal processor to change grayscale of an output image to be displayed on the display based on characteristics of the image signal and characteristics of the display apparatus if a glare level corresponding to the ambient brightness sensed by the first sensor and brightness of the display is greater than a preset threshold.