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Frequency-domain image editor

Every image is transformed to its spectrum, edited by keeping or removing frequency components, and reconstructed by the inverse transform. Choose a filter, or paint directly on the spectrum to erase frequencies.

input f(x,y)

256 × 256 grayscale

spectrum |F(u,v)|

log magnitude · DC centered

output f̂(x,y)

inverse DFT · contrast-normalized

Filter

32
80

frequencies kept: 100%

Paint on spectrum

18 px

With the brush on, drag across the middle panel to zero out those frequencies. The mirror point is erased automatically to keep the result real.

kept removed

Source image

Try: low-pass blurs, high-pass leaves edges, band-pass isolates texture. On stripes, a single frequency, notice the spectrum is two bright points.

radix-2 FFT computed in-browser · rows then columns · no data leaves this page