Service — Computer Vision

Video Annotation

Object tracking with consistent IDs across frames, action recognition, temporal segmentation, and AV scenario annotation. Temporal interpolation reduces frame-by-frame work by 70%. ByteTrack multi-object tracking for high-density scenes. Supporting autonomous vehicles, surveillance, healthcare, and action recognition applications.

70%
Reduction in frame-by-frame work via temporal interpolation between keyframes
ByteTrack
State-of-the-art multi-object tracking for consistent IDs across frames
30fps
Support for high-framerate video — automotive, sports, and security footage
ID-consistent
Track IDs maintained across occlusions, re-entries, and scene cuts
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Object TrackingAction RecognitionTemporal SegmentationByteTrackKeyframe AnnotationTemporal InterpolationAV ScenariosActivity DetectionObject TrackingAction RecognitionTemporal SegmentationByteTrack
What It Is

Image annotation across time — consistency is everything

Video annotation extends image annotation into the temporal dimension. The core challenge is not just labeling what is in each frame — it is maintaining label consistency across frames as objects move, overlap, partially leave frame, and re-enter. Getting this right requires a combination of smart automated tracking and careful human review of edge cases that break automated tracking.

Consider annotating a pedestrian in a busy street scene. In frame 1, the pedestrian is fully visible and easy to box. By frame 47, they are partially occluded by a parked car. By frame 68, they briefly leave frame and re-enter from behind the car. By frame 94, they overlap with another pedestrian for 12 frames. A naive tracking system will either lose the ID during these events or swap IDs with the other pedestrian — both errors that corrupt your training data.

Our video annotation pipeline uses ByteTrack for initial multi-object tracking (SOTA for maintaining IDs through occlusions), combined with temporal interpolation between human-annotated keyframes (typically 1 keyframe every 10–30 frames depending on scene complexity). Human annotators focus their effort on keyframes and occlusion events — where tracking is hardest and most consequential — rather than manually annotating every frame.

For Indian-specific autonomous vehicle data, we have annotators who are familiar with the specific challenges of Indian traffic: two-wheelers weaving between lanes, auto-rickshaws making unexpected turns, pedestrians crossing at unstructured intersections, cattle on roads, and the distinctive right-of-way patterns that Western-trained models do not understand. This domain familiarity is the difference between annotation that actually represents the scene and annotation that imposes Western traffic patterns onto Indian footage.

What is ByteTrack and why do we use it?
ByteTrack is a state-of-the-art multi-object tracking algorithm that associates detections to tracks using both high-confidence and low-confidence detections — most trackers discard low-confidence detections, which leads to ID switches during occlusions. ByteTrack is superior for crowded scenes (pedestrian crowds, dense traffic) and handles re-identification after objects re-enter frame after brief disappearance. We pair it with human QA at all ID-switch events.
What is temporal interpolation?
Rather than manually annotating every frame (at 30fps, a 1-minute video has 1,800 frames), human annotators label keyframes at regular intervals. Our interpolation algorithm then generates annotations for all intermediate frames by linearly or spline-interpolating the bounding box coordinates and mask boundaries between keyframes. Human annotators review interpolated frames at random sample points and at all detected motion discontinuities. The result is 70% less human annotation time with equivalent accuracy on well-behaved tracks.
Video Timeline Annotation
● SPEECH · 3m 12s
● ACTION EVENT
● B-ROLL SEGMENT
● TRANSITION
▼ TIMELINE ANNOTATION TRACK
0:002:164:32 ▶
✓ 14 SEGMENTS · APPROVED
Temporal Annotation

Object tracking with consistent identity across frames

ByteTrack-powered multi-object tracking with temporal interpolation reduces frame-by-frame annotation work 70%. Supports autonomous vehicles, healthcare, and surveillance.

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Live Annotation Interface

Video Timeline Segment Annotation Tool

Annotators label temporal segments across video, audio, and action streams — building datasets for video understanding, action recognition, and multimodal AI training.

ConcaveLabel Studio — Video Annotation · Clip: #8,204 · Duration: 4m 32s · Annotator: Meena R.
AUDIO TRACK
SPEECH
SIL
SPEECH
MUSIC
SPEECH
SIL
0:000:451:302:153:003:454:32
ACTION TRACK
INTRO
B-ROLL
ACTION
B-ROLL
ACTION
OUTRO
CONTENT CLASSIFICATION
PRODUCT DEMONSTRATION
INTERVIEW
TUTORIAL
SPEECH SEGMENTS
14 turns · 3m 12s
ACTION EVENTS
8 detected · 42s
QA STATUS
APPROVED ✓
Task Types

Five video annotation tasks, each temporally consistent

📦
Object Tracking
Bounding box annotation with consistent track IDs across all frames. ByteTrack handles high-confidence tracking; human annotators handle occlusions, re-entries, and ID corrections. Supports multi-class multi-object tracking. Output: COCO tracking JSON or MOT Challenge format.
🏃
Action Recognition
Temporal labeling of actions performed by tracked entities — walking, running, falling, fighting, cooking, assembling. Supports both clip-level classification and frame-level action boundaries (temporal action proposal annotation). Includes intensity and confidence scoring.
Temporal Segmentation
Dividing video into temporal segments by scene, activity, or content type. Scene boundary detection annotation, activity segmentation (shot type changes, action phase transitions), and narrative segmentation for surveillance and sports analytics applications.
🚗
AV Scenario Annotation
Autonomous vehicle-specific video annotation: object tracking of all road actors, lane detection across frames, traffic sign and signal recognition, drivable surface segmentation, and event annotation (near-misses, sudden stops, pedestrian encroachments). Specialist Indian road condition annotators available.
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Medical & Surgical Video
Surgical scene annotation — instrument tracking, phase recognition (incision, dissection, haemostasis), anatomy segmentation across video frames. Endoscopy and laparoscopy annotation by clinical annotators. Supports training surgical AI assistants and robotic surgery systems.
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Surveillance & Security
Person re-identification across camera views, anomaly detection event labeling, crowd density estimation annotation, and security incident classification. Privacy-preserving workflow with face blurring option. GDPR and DPDP-compliant data handling throughout.
The Process

From raw video to temporally consistent labels

01
Video Audit & Annotation Planning
We review a sample of your video footage (typically 5–15 clips) to assess scene complexity, object density, occlusion frequency, frame rate, and domain specificity. From this, we determine the optimal keyframe interval (more frequent for high-motion scenes), which tracking algorithm to use, and which object classes require the most careful human attention. For AV footage, we identify Indian road-specific objects that require domain-specialist annotators.
Scene complexity assessmentKeyframe interval designTracker selectionSpecialist matching
02
Automated Tracking + Keyframe Selection
ByteTrack runs on the full video to generate initial track proposals for all detected objects. Our keyframe selection algorithm identifies the frames with the highest tracking uncertainty — occlusion events, new object entries, track merges, and re-identification events — and marks them as priority human annotation targets. Regular keyframes are selected at the configured interval. Interpolation connects human-annotated keyframes for all intermediate frames.
ByteTrackUncertainty-based keyframe selectionTemporal interpolation70% frame reduction
03
Human Expert Annotation
Domain-specialist annotators review keyframes and all flagged tracking events. They correct ID assignments, refine bounding box and mask boundaries at keyframes, annotate action labels and temporal boundaries, and flag any tracking failures for manual correction. For AV footage: annotators with Indian road experience classify objects that automated detection models typically miss (overcrowded auto-rickshaws, bicycle-loaded goods, informal pedestrian crossing patterns).
Keyframe + event annotationID correctionAction labelingIndian AV specialists
04
QA & Delivery
Automated consistency checks (ID persistence across occlusions, smooth trajectory validation, boundary continuity at keyframes). 15% of videos reviewed by a second annotator with independent ID tracking. Expert spot check on all tracks exceeding 50 frames. Delivery in MOT Challenge format, COCO tracking JSON, or custom format. Includes per-track QA report with ID switch counts, occlusion handling log, and annotator agreement rates.
Trajectory consistency validation15% second-annotator reviewMOT / COCO formatPer-track QA report
Use Cases

Four domains where video annotation directly drives AI performance

🚗
Autonomous Vehicles — Indian Roads
AV perception models trained on Western data fail on Indian roads. Our annotators understand the specific behaviours, objects, and scenarios unique to Indian traffic — auto-rickshaws, cattle, motorbike swarms, unstructured intersections, monsoon visibility — and annotate them with the accuracy needed to train reliable perception systems for Indian deployment.
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Surgical AI & Medical Video
Laparoscopic, endoscopic, and robotic surgery video annotation for training surgical AI assistants. Clinical annotators (surgeons and surgical nurses) label instrument types, anatomical structures, surgical phase boundaries, and critical event markers — data that requires genuine clinical expertise to label correctly.
🏋
Sports Analytics
Player tracking across broadcast and tactical camera footage, action segmentation (pass, shot, tackle, formation change), event annotation, and pose estimation for biomechanical analysis. Supports IPL/cricket, football, and kabaddi analytics applications with sport-specific annotation expertise.
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Surveillance & Public Safety
Person re-identification, crowd monitoring, anomaly detection labeling, and incident classification for smart city and security applications. Privacy-compliant workflow with automated face blurring, DPDP-compliant data handling, and annotator NDAs. Supports both CCTV and body-cam footage.
Pricing

Per-minute video
pricing by complexity

Video annotation is priced per minute of footage based on scene complexity, object density, and task type. Temporal interpolation savings are passed directly to you — you pay for human annotation time, not automated tracking.

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Simple tracking (low density, clear scenes)₹800–1,500 / min
Complex tracking (dense, occlusions)₹1,500–3,000 / min
AV scenario annotation (Indian roads)₹2,000–4,000 / min
Medical / surgical video₹3,000–8,000 / min
Action recognition + tracking₹2,500–5,000 / min
Minimum project30 minutes

Get 5 minutes of video annotated free

Send us a 5-minute clip from your dataset. We will return fully tracked and labeled video with IoU metrics and ID consistency report — no cost, no commitment.