1. A projection type display device comprising: projection means that projects an input image, representing an object on a background and corresponding to an input video signal, onto a projection surface on which a user writes information, and processing means that, upon receiving a photographing instruction to perform photographing, stops projection by the projection means and photographs the projection surface to generate a photographed image, and detects a difference between the color of the background in the input image and the color of the projection surface in the photographed image, to generate a corrected image by correcting the color of the input image or the photographed image so as to reduce the difference, and generates a recorded image by superimposing the corrected image on the other of the input image and the photographed image.