What it does
Finds regions of the image by color, motion, or edges and draws boxes, markers, and labels around them.
In computer vision, a blob is just a connected region of pixels that stands out from its surroundings, by movement, by color, or by brightness. Blob tracking is the step that gives those regions identity: matching this frame’s detections against the last frame’s, so that blob number three is still blob number three a second later. It is the workhorse behind people counters, touch tables, and interactive installations, and TouchDesigner made it a staple of that world.
The aesthetic came later, and it came from showing the work. A tracker’s debug view, boxes locked onto dancers, crosshairs on passing cars, coordinates ticking beside every moving thing, turned out to be more compelling than whatever the tracker was built to do. That surveillance-graphics look spread from installation art into music videos and TikTok edits, and it carries an unmistakable mood: the camera is no longer neutral, something is reading the scene.
Modulate’s Tracking effect runs the real pipeline, not a decal. It detects regions by motion, by a chosen color, or by edges, filters out the specks, and follows each blob with stable identity and adjustable smoothing, so boxes glide with their subjects instead of flickering. The overlay is drawn as true vector graphics: boxes, markers, connection lines strung between blobs, and labels reading out live coordinates. It can even host other effects inside the tracked regions, so a pixelation or blur follows whatever it finds.
Signature looks
Surveillance feed
White boxes, crosshair centres, and id-plus-coordinate readouts on every moving subject. Plain footage starts reading as CCTV that has begun paying attention.
Dance tracker
Each performer gets a box in their own color, with connection lines strung between them that stretch and swing as they move. The stage-visual staple, live on any clip.
Auto censor
Pixelation hosted inside the tracked boxes, so the mosaic follows the subject wherever it goes. The documentary blur, without keyframing a mask by hand.
Try it on your own footage
This effect runs live in the Modulate editor, free with no signup — or start from the free tool page for a guided setup.
Common questions
What is blob tracking?
Blob tracking is a computer-vision technique that finds connected regions of interest in each video frame, usually regions that are moving, and follows each one over time so it keeps a stable identity. Visually it is known for its overlay: bounding boxes, crosshairs, and coordinate labels attached to whatever the tracker is following.
What is a blob in computer vision?
A blob is a connected group of pixels that shares some property that separates it from the background: it moved when the background did not, it matches a target color, or it forms a dense cluster of edges. Blob detection finds those regions in a single frame; blob tracking links them across frames.
How is blob tracking different from object tracking?
Blob tracking is model-free: it follows any region that stands out, with no idea what the region is. Object tracking usually implies recognition, a system trained to find faces or cars specifically. The model-free quality is part of the aesthetic: raw boxes and numbers, no neat labels, a machine reporting movement without understanding it.
Why is blob tracking associated with TouchDesigner?
TouchDesigner is the standard tool for interactive installations, where blob tracking turns camera input into triggers, so most tutorials and viral breakdowns of the look are built there. The effect itself is older and broader than any one tool; TouchDesigner is simply where a generation of visual artists first met it.
How can I add blob tracking to a video?
Modulate’s free blob tracker runs in your browser: drop in a clip, tune the detection until the boxes lock on, and export. The full editor opens up the rest of the effect: color and edge detection, per-blob palettes, connection lines, label styles, and effects hosted inside the tracked regions.
Related effects
Datamoshing
Smears moving parts of the image into blocky trails, like a corrupted video that never gets a clean frame.
Pixel sorting
Sorts runs of pixels into glitchy streaks by brightness, hue, or saturation. The classic pixel sorting look.
ASCII art effect
Rebuilds the image out of text characters, matching brighter and darker glyphs to the light and dark areas underneath.
Slit-scan effect
Each pixel shows a different moment in time — a gradient or control map melts the image across recent frames for slit-scan, rolling-shutter, and time-displacement looks.