Add Google‑style docstrings to YOLO utility functions

[V4Vikaskumar]

This PR adds proper Google‑style docstrings to the YOLO utility functions in backend/app/utils/YOLO.py, improving documentation, readability, and maintainability. These docstrings cover functional purpose, argument types, and return values.

📌 Functions with Added Docstrings

• ✅ YOLO_util_nms — Non‑Maximum Suppression
• ✅ YOLO_util_multiclass_nms — Per‑class NMS
• ✅ YOLO_util_compute_iou — IoU calculation
• ✅ YOLO_util_xywh2xyxy — Bounding box format conversion
• ✅ YOLO_util_draw_detections — Detection visualization
• ✅ YOLO_util_draw_box — Bounding box drawing
• ✅ YOLO_util_draw_text — Text label drawing
• ✅ YOLO_util_draw_masks — Overlay mask drawing

📘 What Was Added

• Function descriptions explaining what each utility does
• Detailed Args section with types and descriptions
• Clear Returns section specifying what each function returns
• Maintains consistent Google‑style docstring format

🛠 Benefits

• ✅ Improves code documentation and clarity
• ✅ Helps new contributors understand YOLO utility functions
• ✅ Follows Python docstring best practices
• ✅ Aids IDE autocompletion and type checking

💫 Background

The backend/app/utils/YOLO.py file contains several object detection helper functions that did not have docstrings, making it harder for maintainers and contributors to understand their purpose and usage. This PR fills that gap by adding consistent and helpful documentation.

fixes (#847)

Summary by CodeRabbit

• Documentation
  • Enhanced documentation for core utility functions to improve code maintainability and provide clearer guidance for developers working with these components.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

📝 Walkthrough

Walkthrough

This pull request adds comprehensive docstrings to nine YOLO utility functions in the backend, documenting NMS, IoU computation, coordinate conversion, bounding box drawing, mask visualization, and model path selection. No functional logic or API signatures were modified.

Changes

Cohort / File(s)	Summary
YOLO Utility Documentation backend/app/utils/YOLO.py	Added detailed docstrings to 9 functions: YOLO_util_nms, YOLO_util_multiclass_nms, YOLO_util_compute_iou, YOLO_util_xywh2xyxy, YOLO_util_draw_detections, YOLO_util_draw_box, YOLO_util_draw_text, YOLO_util_draw_masks, and YOLO_util_get_model_path. Docstrings describe parameters, behavior, and return values. No code logic or signatures modified.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Poem

🐰 A hop through docs, so clear and bright,
Each function now explains its might,
NMS to masks, all set with care,
Better code for those who dare!
—The Documentation Bunny 📝✨

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: adding Google-style docstrings to YOLO utility functions, which matches the changeset.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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Actionable comments posted: 0

🧹 Nitpick comments (1)

backend/app/utils/YOLO.py (1)

229-243: Comprehensive docstring for the main visualization function!

The docstring is well-structured and documents all parameters clearly.

One minor optional clarification: The confidence_threshold description could be more precise. Currently it says "Minimum score to display labels," but the implementation shows detections below this threshold with "unknown" labels rather than hiding them entirely. Consider clarifying this as "Minimum score to display class-specific labels (lower scores show 'unknown')."

📜 Review details

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 81286fa and 73181f4.

📒 Files selected for processing (1)

• backend/app/utils/YOLO.py

🔇 Additional comments (10)

backend/app/utils/YOLO.py (10)

94-107: Excellent docstring for NMS function!

The docstring clearly explains the Non-Maximum Suppression algorithm, provides accurate type information, and describes the return value. The format follows Google-style conventions correctly.

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131-142: Well-documented class-wise NMS function!

The docstring effectively explains how class-wise NMS differs from standard NMS, with accurate type information and clear parameter descriptions.

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144-169: Helpful inline comments that improve code clarity!

The inline comments, especially the example showing [0, 0, 1, 2, 2] -> [0, 1, 2], make the algorithm easier to understand. The step-by-step explanations are well-balanced and aid maintainability.

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174-183: Clear and accurate IoU computation docstring!

The docstring correctly describes the IoU computation between a single box and multiple boxes, with proper type annotations.

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206-215: Well-documented coordinate conversion function!

The docstring clearly explains the bounding box format conversion from center-based to corner-based coordinates, making the function's purpose immediately clear.

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245-278: Excellent inline documentation for the rendering pipeline!

The comments effectively guide readers through the visualization process, from dynamic sizing calculations to the final rendering steps. This significantly improves code maintainability.

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289-302: Clean and precise docstring for box drawing!

The docstring properly documents the function parameters including default values, with type information that complements the function signature's type hints.

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316-332: Thorough docstring with helpful context!

The docstring effectively documents the text rendering function, and the note about font_size being scaled by the parent function provides useful context about how this utility is typically used.

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334-352: Detailed comments that clarify text rendering logic!

The inline comments, especially the multi-line explanation of the background rectangle positioning, help readers understand the coordinate calculations and rendering choices.

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369-383: Complete documentation for mask rendering!

The docstring clearly explains the semi-transparent mask overlay functionality with proper type annotations and default values. The inline comment about copying the image is a helpful reminder about avoiding side effects.