1. A display apparatus, comprising: an input unit configured to input an image to be displayed; a determination unit configured to determine whether the input image is an image obtained by 2-3 pull down method; an PP conversion unit configured to, when the input image is an image obtained by 2-3 pull down method, convert the input image from an interlaced image to a progressive image; a double speed frame unit configured to convert, when the input image is an image obtained by 2-3 pull down method, frames of the progressive image converted by the I/P conversion unit; and a display unit configured to replace at least one of frame images converted by the double speed frame unit with a different image, and display the frame images while inverting the electrical polarity thereof on a frame-by-frame basis.