Annular transistors are positioned with respect to the n-well diffusion region so that the active channels of the transistors are completely within the diffusion region, thereby avoiding the formation of the edges at the boundary between n active channel regions and adjacent field oxide region, which are susceptible to the effect of the ionizing radiation. The representative value calculation unit is configured to calculate, when areas obtained by dividing a frame image in units of a plurality of pixels are each assumed as a block, an average value of pixel values within each block as a representative value of the block based on an input video signal. The performance report includes an indication of the predicted root cause.