An imaging apparatus includes an imaging unit, a random seed generating unit, a pseudo-random number generating unit, and a special image processing unit. The imaging unit photographs a subject to obtain image data. The random seed generating unit generates a random seed to decide a pseudo-random number sequence. The pseudo-random number generating unit generates a pseudo-random number in accordance with the generated random seed. The special image processing unit performs special image processing to apply a special effect to the image data based on the generated pseudo-random number. The random seed is decided during photography.