A desired structure is selectively imaged by photoacoustic imaging. Photoacoustic signals are detected, and the detected photoacoustic signals are reconstructed to generate photoacoustic image data. A Fourier transform in a two-dimensional or higher dimensional space is applied to the photoacoustic image data to generate spatial frequency domain photoacoustic image data. Given spatial frequency components are extracted from the spatial frequency domain photoacoustic image data, and an inverse Fourier transform is applied to the extracted spatial frequency components to generate spatial frequency-processed photoacoustic image data.
