1. A photoacoustic image generation device comprising: a light source that emits light to be applied to a subject; an acoustic wave detection unit that detects photoacoustic waves emitted from the interior of the subject due to the light applied to the subject; a photoacoustic image generation unit that reconstructs photoacoustic signals to generate image data, the photoacoustic signals being detection signals of the photoacoustic waves; a Fourier transform unit that applies a Fourier transform in a two-dimensional or higher dimensional space to the image data to generate spatial frequency domain image data; a spatial frequency processing unit that extracts given spatial frequency components from the spatial frequency domain image data; and an inverse Fourier transform unit that applies an inverse Fourier transform to the extracted spatial frequency components to generate spatial frequency-processed image data wherein the spatial frequency processing unit extracts spatial frequency components of frequencies not lower than a first spatial frequency and not higher than a second spatial frequency that is higher than the first spatial frequency.