Fourier transform of the actual star-forming regions observed by Herschel at 350 μm with a 25′′ resolution. Shown are the amplitudes of the decomposed images of Aquila (top left to right) and Rosette (bottom left to right); the scale sizes S_j are annotated at the bottom of the panels. For the original Aquila images with 4096 × 4096  3′′ pixels and Rosette images with 2048 × 2048  3′′ pixels, the panels present the Fourier amplitudes within the range of spatial frequencies from zero to one-third of the Nyquist frequency (0.17 arcsec^-1). For better visibility, the spatial frequencies and the pixel values are somewhat limited in range; the color coding is linear.