VFX Atlas
M 159 / 18307 Filters & Motionalgorithm output

Fourier Low-Pass Filter

filtering, restoration & motion

Typeface · DM Mono

Real-world algorithm demonstration, applied to a NASA portrait.
Real-world algorithm demonstration, applied to a NASA portrait.Image: NASA / Eileen Collins · scikit-image (public domain)View source ↗

Prompt

Apply Fourier Low-Pass Filter to suppress fine textures, grain, and sharp boundaries while retaining broad silhouettes and large tonal masses. Create smooth, softly blended color regions with reduced microcontrast and gently diffused lighting. Avoid directional smears and added surface texture. Preserve the original subject and composition.

Paste it into LetzAI with your own image to apply the effect ↗

Identify

Broad shapes remain, details disappear.

Principle

High frequencies1 are suppressed in the FFT2 space.

Try it out

Compare radius and sharpness.

Classification

Calculated image processing result.

Further examples · 7 images

Lowpass picture
02 Lowpass pictureA side-by-side comparison shows an original image and its low-pass filtered version. High-frequency details like hair and guitar strings are removed, leaving only the blurred low-frequency shapes.Dake, original picture by Manfred Werner (Tsui) · CC BY-SA 3.0 · Wikimedia Commons
2D Fourier Transform and Base Images
03 2D Fourier Transform and Base ImagesThe image maps sinusoidal patterns to specific points in frequency space. This demonstrates the basic component analysis required to identify and suppress high frequencies in a Fourier low-pass operation.Felix Lugauer and Jens Wetzl · CC BY 4.0 · Wikimedia Commons
Fourier Low-Pass Filter, applied to “Match and match labels, 100 years ago”
04 Fourier Low-Pass Filter, applied to “Match and match labels, 100 years ago”Small text and fine line work on the vintage matchbox labels are removed. The resulting image retains large blocks of color and the basic rectangular grid through high-frequency suppression.Takkk (photo); processed for the Atlas · CC BY-SA 3.0 · Wikimedia Commons
Fourier Low-Pass Filter, applied to “Beige and brown oil-paper umbrella on the edge of a wooden house in Luang Praban”
05 Fourier Low-Pass Filter, applied to “Beige and brown oil-paper umbrella on the edge of a wooden house in Luang Praban”Wood grain textures and individual umbrella spokes disappear in the processed half. The filter preserves the broad circular form of the oil-paper umbrella and the horizontal lines of the wooden house.Basile Morin (photo); processed for the Atlas · CC BY-SA 4.0 · Wikimedia Commons
Fourier Low-Pass Filter, applied to “Cirsium eriophorum (Kozara National Park, Republika Srpska)”
06 Fourier Low-Pass Filter, applied to “Cirsium eriophorum (Kozara National Park, Republika Srpska)”The sharp spikes and fine purple petals of the Cirsium eriophorum are smoothed away. Low-frequency components maintain the overall globe shape and green stems while eliminating texture detail.Petar Milošević (photo); processed for the Atlas · CC BY-SA 4.0 · Wikimedia Commons
AI illustration: A forest photo is shown alongside a version where sharp details are remov
07 AI illustration: A forest photo is shown alongside a version where sharp details are removA forest photo is shown alongside a version where sharp details are removed. The UI includes an FFT spectrum visualization, indicating high-frequency suppression to achieve the resulting blur.Illustration generated for the Atlas (AI)