1. In a display device comprising a digital circuit for subjecting an input image to image deformation processing, an operating unit for entering an image deformation command, a CPU into which the image deformation command from the operating unit is entered, and a nonvolatile memory controlled by the CPU, the CPU continuing to transmit, when the image deformation command from the operating unit continues to be entered, the image deformation command to the digital circuit, the digital circuit sequentially making calculation for image deformation when the image deformation command continues to be transmitted from the CPU, to perform the image deformation processing such that the degree of image deformation is gradually increased, the CPU comprising means for receiving, when the image deformation processing by the digital circuit is terminated, the degree of image deformation at the time of the termination from the digital circuit, and storing the received degree of image deformation in the nonvolatile memory, and means for causing, when an image deformed state is returned to an initial state before the deformation by turning the power of the display device on or off, for example, the digital circuit to subject the input image to the image deformation processing until the degree of image deformation stored in the nonvolatile memory is reached on the basis of the degree of image deformation stored in the nonvolatile memory.