Computer Vision / Deep Learning / MLOps
VisionSeg
Semantic Segmentation & Production ML Engineering
A configurable computer vision framework built around DeepLabV3 and ResNet-50, connecting pixel-level segmentation with reproducible evaluation and deployment-oriented engineering.
Conceptual demonstration — not model output
Original synthetic vehicle · illustrative semantic regions.
Beyond Model Training
Semantic segmentation assigns a class to every pixel. Reliable systems must also address inconsistent image dimensions, class imbalance, ambiguous boundaries, similar-looking classes, and dataset leakage.
VisionSeg is an independent framework design connecting modular preprocessing, DeepLabV3 training, evaluation, error analysis, and inference. Reproducibility and inference performance are engineering concerns throughout the lifecycle.
System Architecture
VisionSeg / Semantic segmentation
Context at every scale.
A class at every pixel.
SYSTEM FIGURE / 01
DeepLabV3 · ResNet-50
An image-only forward path, from spatial features to semantic classes. Paired labels support learning and offline evaluation separately.
Synthetic RGB image
Resize & pad
Preserve aspect ratio.
Tensor conversion + normalization.
Model-ready tensor
Image only at inference
Paired labels / learning & evaluation only. Class-index masks use nearest-neighbor resizing; class IDs remain discrete.
DeepLabV3 + ResNet-50
Standard Torchvision model · functional forward path
Residual feature extraction
Dilated later stages retain spatial detail.
Schematic dimensions
One shared spatial feature map feeds all five branches.
Concatenate & project
Join branch features · 1 × 1 projection
- 3 × 3 convRefine features
- 1 × 1 class scoresPer-pixel logits
- Bilinear resizeModel-input resolution
Segmentation outputs & evaluation
Argmax across class scores
One class index per pixel
Pixel confusion matrix
Class intersections & unions
- Per-class IoU
- Mean IoU
- Foreground mean IoU
Metric utilities implemented.
Analysis runner remains a scaffold.
Atrous / r₂. A dilated kernel samples a wider neighborhood without another spatial downsampling step. Sampling grids are conceptual; dilation rates are symbolic.
Text architecture & implementation scope
RGB images are resized and padded without changing aspect ratio, converted to tensors and normalized. ResNet-50 extracts spatial features. DeepLabV3’s ASPP applies parallel pointwise, atrous and image-pooling branches, concatenates their outputs, and projects them before a segmentation classifier. Logits are resized to the model-input resolution; argmax assigns a semantic class per pixel.
Ground-truth masks are separate from inference inputs. Paired masks support supervised development; held-out masks and predicted class maps support offline confusion-matrix and IoU evaluation. The model factory supports an optional auxiliary head for training; this figure shows the main prediction path. Training and inference runners are scaffolds, so the figure does not assert a completed training run, a trained checkpoint, or a deployed system.
Dataset checks, transformations, model construction, class selection and metric calculations are verified in the local vehicle-part semantic segmentation implementation. ASPP and resizing follow the standard Torchvision architecture; no extra DeepLabV3+ decoder is shown. All images, feature maps and sampling patterns are original synthetic schematics, with no measured activations or performance values.
Interactive Semantic Segmentation
A class for every pixel
Original SVG vehicle · synthetic semantic regionsConceptual demonstration — not model output
Synthetic prediction regions over the original illustration.
The reference and prediction shapes are authored examples. Their differences illustrate boundary errors; no prediction accuracy is claimed.
Front Door
The front door region in the synthetic vehicle side view.
Understanding Where Segmentation Fails
- mIoU
- Mean intersection over union across classes.
- Foreground mIoU
- Mean IoU excluding background.
- Per-Class IoU
- Segmentation quality for individual categories.
Illustrative confusion matrix
Authored, row-normalized percentages. These synthetic values are not experiment results or a VisionSeg benchmark.
Rows: actual class · columns: predicted class
Select a cell; use arrow keys to explore.
| Actual ↓ Predicted → | BG | FD | RD | FF | RF | DH |
|---|---|---|---|---|---|---|
| Background | ||||||
| Front Door | ||||||
| Rear Door | ||||||
| Front Fender | ||||||
| Rear Fender | ||||||
| Door Handle |
Scroll horizontally to inspect every class →
Front Door Rear Door
Illustrative: 12% of pixels labeled Front Door are assigned Rear Door in this synthetic matrix. Visually similar components can share features. Review class-level confusion and difficult boundaries.
Error review workflow design
Validation Predictions
Per-Class Evaluation
Confusion Analysis
Difficult Example Review
Improvement Planning
Scroll to explore the pipeline
Small objects
Inspect handles and other fine details that can blend into surrounding regions.
Similar-looking classes
Review front/rear panel confusion rather than relying on aggregate scores.
Boundary errors
Inspect transitions between adjacent classes and ambiguous edges.
Engineering Beyond Accuracy
Architectural decisions. These capabilities are described as designs where implementation is not independently verified.
Aspect-Ratio Preservation
Design preprocessing to resize and pad images without distorting their original geometry.
Mask-Safe Preprocessing
Use nearest-neighbor interpolation to preserve discrete segmentation class IDs.
Foreground-Aware Evaluation
Measure foreground segmentation separately to avoid misleading background-dominated metrics.
Reproducible Experiments
Use configuration-driven training and consistent evaluation procedures.
Engineering Roadmap
Implemented building blocks, unfinished runners, and planned integrations. Status reflects inspected source code; it does not imply a completed training run or production deployment.
| Capability | Engineering purpose | Status |
|---|---|---|
| Paired data & preprocessingValidate image–mask pairs; preserve geometry and class IDs.dataset.py · transforms.py | Validate image–mask pairs; preserve geometry and class IDs.dataset.py · transforms.py | Implemented |
| DeepLabV3 forward pathConstruct the model and select a class per pixel.model.py · model tests | Construct the model and select a class per pixel.model.py · model tests | Implemented |
| Segmentation metric utilitiesAccumulate confusion; compute per-class, mean and foreground IoU.metrics.py · metric tests | Accumulate confusion; compute per-class, mean and foreground IoU.metrics.py · metric tests | Implemented |
| Training & evaluation runnersConnect configured training, error review and model selection.train.py · analysis scripts are empty | Connect configured training, error review and model selection.train.py · analysis scripts are empty | Scaffold |
| Image-to-mask inference CLIPackage image validation, preprocessing and prediction output.inference.py is empty | Package image validation, preprocessing and prediction output.inference.py is empty | Scaffold |
| FastAPI servingExpose a prediction interface.Portfolio integration target | Expose a prediction interface.Portfolio integration target | Planned |
| Docker & ONNXPackage a runtime and investigate model export.Portfolio integration targets | Package a runtime and investigate model export.Portfolio integration targets | Planned |
| CI/CD automationAutomate engineering checks with GitHub Actions.Portfolio integration target | Automate engineering checks with GitHub Actions.Portfolio integration target | Planned |
Scaffold = entry point exists without an implemented workflow. FastAPI, Docker, ONNX and GitHub Actions remain integration targets.
Technology Stack
Deep Learning
- PyTorch
- Torchvision
- DeepLabV3
- ResNet-50
Data Processing
- NumPy
- Pillow
Evaluation
- mIoU
- Per-Class IoU
- Confusion Matrix
Visualization
- Matplotlib
Engineering
- Python
- YAML
- Pytest
Planned Integrations
- FastAPI · Planned
- Docker · Planned
- ONNX · Planned
- GitHub Actions · Planned