A circuit device includes an image processing circuit and a comparison circuit. The image processing circuit performs a first mapping process and a first rotation process on an input image to generate an image for a head up display. The image processing circuit performs, on an image, a second mapping process that is a reverse mapping process of the first mapping process and a second rotation process that is a reverse rotation process of the first rotation process to generate an image. The comparison circuit performs a comparison between the image and the image and outputs a result of the comparison as information for detecting an error in the image.