Case Study
Polygon Segmentation · Instance Seg · Industrial & Automotive

Polygon Segmentation — Industrial & Automotive

1,000 images with pixel-precise polygon instance segmentation for industrial and automotive applications. Subcontracted project delivered under NDA on self-hosted CVAT.

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The Challenge

When bounding boxes aren’t enough, polygon segmentation delivers pixel-level object boundaries. Instance segmentation requires annotators to trace the exact contour of every object — distinguishing individual instances even when they overlap, capturing irregular shapes that rectangles can’t represent, and maintaining boundary precision across hundreds of vertices per object.

TechAI Remote was subcontracted to deliver polygon instance segmentation across 1,000 images spanning industrial and automotive domains. The client’s identity is protected under NDA. Every annotation was produced on our self-hosted CVAT instance with full three-layer QA, delivered in client-specified export formats.

Project Management Keylian Namisi
QA Lead Ibrahim Ouma
Images Annotated 1,000
Platform CVAT v2.58.0 (Self-Hosted)
Polygon segmentation project metrics - 1000 images, instance segmentation

Project metrics: 1,000 images annotated with pixel-precise polygon instance segmentation across industrial and automotive domains

Annotation Details

Why Polygons Over Bounding Boxes

Bounding boxes include significant background pixels around irregular objects — a person’s silhouette, a car’s contour, or an industrial component’s shape. Polygon segmentation traces the actual object boundary, giving models pixel-accurate training data. This is critical for applications where background contamination in labels directly degrades model performance.

Annotation Approach

AspectDetail
TypeInstance segmentation (individual object polygons)
PrecisionPixel-level boundary tracing
Vertices50–300+ points per complex object
Overlap HandlingSeparate polygon per instance, even when overlapping
DomainsIndustrial components & automotive scenes

Infrastructure

ComponentDetail
PlatformCVAT v2.58.0 (self-hosted)
ServerHetzner dedicated server
DeploymentDocker with SSL
Data SecurityData never leaves our server
ClientNDA-protected

Export Formats

FormatUse Case
COCO JSONInstance segmentation training
Pascal VOCSegmentation masks
CVAT JSONClient CVAT import
Segmentation MasksPNG mask export per class

Annotation in Production

Real screenshots from our self-hosted CVAT instance showing polygon instance segmentation. Each image demonstrates the precision of boundary tracing — individual polygons per object instance with class-specific color coding and the CVAT objects panel showing label assignments.

CVAT polygon segmentation - precise boundary tracing on industrial/automotive objects CVAT polygon segmentation - instance-level object separation with color-coded polygons CVAT polygon segmentation - multi-object scene with detailed polygon boundaries

Pixel-precise polygon boundaries traced around individual object instances. Each polygon captures the exact contour of the object with class-specific color coding. Objects panel shows instance-level label assignments.

Why Instance Segmentation Matters

Beyond Bounding Boxes

A bounding box around a car includes the road beneath it, the sky above it, and parts of adjacent vehicles. For applications like automated inspection, robotic manipulation, or autonomous navigation, this background noise in training labels degrades model precision. Polygon segmentation eliminates it — the model learns exactly where the object is, pixel by pixel.

Instance vs. Semantic

Semantic segmentation labels every pixel with a class but doesn’t distinguish between individual objects. Instance segmentation goes further — each object gets its own unique polygon, even when multiple objects of the same class overlap. This is essential for counting, tracking, and understanding spatial relationships between objects.

Industrial Applications

Manufacturing quality control, component inspection, defect detection, and robotic pick-and-place all require precise object boundaries. A polygon that’s off by even a few pixels can mean the difference between a correctly identified defect and a false negative in a production line.

Automotive Applications

Lane boundaries, vehicle silhouettes, pedestrian contours, and road surface segmentation all demand polygon-level precision. Autonomous driving perception models trained on polygon annotations consistently outperform those trained on bounding boxes for tasks requiring spatial understanding.

Key insight: Polygon segmentation is 3–5x slower than bounding box annotation per image. Every vertex must be placed precisely, complex shapes require hundreds of points, and overlapping instances need careful separation. This is why it commands premium pricing — and why quality control is critical. A single sloppy polygon can corrupt an entire training batch.

How We Delivered This Project

Annotation Workflow

  • Guidelines review: Client annotation specifications reviewed — class definitions, boundary rules, overlap handling, and edge case protocols
  • Task setup: 1,000 images uploaded to self-hosted CVAT, batched for parallel annotation
  • Polygon tracing: Annotators trace precise object boundaries using CVAT’s polygon tool, placing vertices along the object contour
  • Instance separation: Overlapping objects receive separate polygons with distinct instance IDs
  • Boundary refinement: Zoom-level vertex adjustment for pixel-precise boundaries on complex shapes

Quality Assurance

  • Stage 1 — Self-check: Annotator zooms to 200%+ and reviews every polygon boundary for precision
  • Stage 2 — Peer review: Second annotator validates boundary tightness, instance separation, and class accuracy
  • Stage 3 — QA Lead final: Ibrahim Ouma performs final validation with focus on complex overlapping instances and edge cases
  • Boundary precision: Polygon edges must follow the object contour within 2–3 pixels
  • Completeness: Every visible object instance annotated — no missed instances
  • Overall QA target: 98.5% accuracy across all annotations

Who This Serves

Polygon instance segmentation supports teams building:

  • Autonomous vehicles: Precise vehicle, pedestrian, and lane segmentation for perception models
  • Industrial inspection: Component boundary detection for automated quality control
  • Manufacturing: Defect localization and part segmentation for robotic assembly
  • Medical imaging: Organ and lesion boundary delineation (transferable methodology)
  • Robotics: Object boundary understanding for precise grasping and manipulation

NDA-protected delivery: This project was delivered under subcontract with full NDA protection. Client identity, specific object classes, and detailed dataset characteristics are confidential. The screenshots and methodology shown here demonstrate our polygon segmentation capability without exposing protected information.

Need Polygon Segmentation?

Pixel-precise instance segmentation for industrial, automotive, or any domain. Start with a free pilot — same CVAT infrastructure, same QA pipeline, same 98.5% accuracy guarantee.