A dynamic image processing apparatus includes a hardware processor. The hardware processor obtains a frequency characteristic of density change of a dynamic image in a time direction. The dynamic image is obtained by imaging at least one breathing cycle or pulsation cycle. Further, the hardware processor obtains peak frequencies in a frequency range for a type of diagnosis target based on the obtained frequency characteristic. Further, the hardware processor determines at least one representative frequency including a maximum peak frequency an intensity of which is highest among the obtained peak frequencies. Further, the hardware processor performs time-direction filtering on the dynamic image using cutoff frequencies to emphasize the determined representative frequency.
