VFX Atlas
M 030 / 18301 Edge & Featuresalgorithm output

Blob Detection

edge & features

Typeface · Syne Mono

Atlas demonstration: the free source photo and the computed Blob Detection. The image captures a wide seascape featuring a distant city skyline and a small boat in the foreground. The computational process perfectly isolates the high-contrast buildings and the dark silhouette of the rower against the shimmering water.
Atlas demonstration: the free source photo and the computed Blob Detection. The image captures a wide seascape featuring a distant city skyline and a small boat in the foreground. The computational process perfectly isolates the high-contrast buildings and the dark silhouette of the rower against the shimmering water.Image: Isaak Dury isaakdury · CC0 (via Wikimedia Commons), processed for the AtlasView source ↗

Prompt

Apply Blob Detection with thin cyan circles centered on compact bright or dark patches that contrast with their surroundings. Vary circle diameters to indicate each blob's estimated extent, including small texture spots and larger rounded regions. Preserve natural photographic detail beneath the overlay. Keep the original subject and composition.

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

Identify

Circles mark compact light or dark regions, with circle size indicating each detected blob's estimated extent.

Principle

A common method applies a scale-normalized Laplacian1 across several blur levels to find regions contrasting with their surroundings. Local extrema2 across position and blur level select blob centers and characteristic sizes.

Try it out

Vary the detection threshold to see which faint regions disappear and which strong blobs remain.

Classification

Calculated image processing result.

Further examples · 9 images

Blob Detection, applied to “Lance Asper 2016-10-24 (Unsplash LZMyglhFp4I)”
02 Blob Detection, applied to “Lance Asper 2016-10-24 (Unsplash LZMyglhFp4I)”A lone vessel is seen from a high aerial perspective surrounded by vast, dark water. The algorithm densely populates the bright hull of the boat with markers, effectively separating it from the uniform darkness of the sea.Lance Asper lance_asper (photo); processed for the Atlas · CC0 · Wikimedia Commons
Blob Detection, applied to “StrungLamps@nightAlley”
03 Blob Detection, applied to “StrungLamps@nightAlley”String lights hang above a narrow, cobblestone alleyway at night, creating numerous bright points of light. The effect is displayed clearly as it maps each individual bulb and reflection to a corresponding circular marker.Matthew Skinner (photo); processed for the Atlas · CC0 · Wikimedia Commons
Blob Detection, applied to “Neon Dollar Sign (Unsplash)”
04 Blob Detection, applied to “Neon Dollar Sign (Unsplash)”A stylized dollar sign is rendered in simple gray lines against a stark black background. The process has densely populated the curves of the symbol with circles, identifying the high contrast between the lines and the dark void.Jimi Filipovski jimiburg (photo); processed for the Atlas · CC0 · Wikimedia Commons
Blob Detection, applied to “City covered in snow (Unsplash)”
05 Blob Detection, applied to “City covered in snow (Unsplash)”A snowy cityscape is shown with historic spires and rooftops under a twilight sky. The algorithm has identified the circular windows, spire tips, and rounded snowy mounds, effectively mapping the town's complex silhouette.Ilya Orehov iliched (photo); processed for the Atlas · CC0 · Wikimedia Commons
Blob Detection, applied to “Dartmouth Street Facade, construction of the McKim Building”
06 Blob Detection, applied to “Dartmouth Street Facade, construction of the McKim Building”A historical photograph depicts a masonry building under construction with exposed window frames. The algorithm highlights geometric points of interest, notably clustering around the vertical support beams and the stark edges of the building facade.Stevens, Edward F. (Edward Fletcher), 1860-1946; McKim, Mead & White (photo); processed for the Atlas · Public domain · Wikimedia Commons
Blob Detection, applied to “Munra Point Trail, Cascade Locks”
07 Blob Detection, applied to “Munra Point Trail, Cascade Locks”Misty, dark mountains rise through a layer of low-hanging clouds in this landscape view. Yellow markers map out the peaks and localized light patches within the fog, though the organic shapes result in a scattered distribution.Patrick Marré (photo); processed for the Atlas · CC0 · Wikimedia Commons
Blob Detection, applied to “String musician's hands (Unsplash)”
08 Blob Detection, applied to “String musician's hands (Unsplash)”A close-up view shows a hand positioned against the strings of a dark wooden instrument. The detection method successfully tracks the circular light reflections along the strings and the highlights on the musician's skin.Cole Hutson colehutson (photo); processed for the Atlas · CC0 · Wikimedia Commons
Blob Detection, applied to “Vatican City (Unsplash)”
09 Blob Detection, applied to “Vatican City (Unsplash)”This image captures the silhouette of a dome and architectural details seen through a window pane. Yellow circles cluster around the highlights and circular ornaments of the building, tracing its structured geometry.Ilya Yakover ilyayakover (photo); processed for the Atlas · CC0 · Wikimedia Commons

Sources