CNN License Plate Detection Without Segmentation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicle license plate recognition systems are vulnerable to environmental factors and require precise camera or sensor positioning, leading to inaccuracies and failures in detecting and recognizing license plates under varying conditions and angles.

Innovation Solution

The use of convolutional neural networks (CNNs) trained to detect and decode license plates without relying on pre-defined key points or landmarks, allowing for accurate recognition across different positions, angles, and environmental conditions, including occluded or damaged plates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional license plate recognition systems use pre-determined distance and angle requirements, then measurement precision is improved, but adaptability deteriorates

Engineering Contradiction:
Improvelicense plate detection accuracyVSAvoidtolerance to varying positions and angles
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent transforms the rigid distance and angle parameters into flexible learning parameters through CNN training. The network learns optimal detection parameters from training data covering various distances and angles, enabling accurate detection without pre-determined geometric constraints while maintaining measurement precision through learned feature representations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system transitions from static geometric constraints to dynamic adaptive detection. The CNN model adapts to different license plate positions, angles, and environmental conditions by learning from diverse training data, making the detection system flexible and responsive to varying operational conditions rather than requiring fixed camera positioning.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If character segmentation methods like Connected Components or HOG are used, then manufacturing precision is improved, but reliability deteriorates

Engineering Contradiction:
Improvecharacter segmentation accuracyVSAvoidrobustness to environmental factors
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent replaces traditional mechanical segmentation approaches (Connected Components, HOG) with a neural network-based holistic detection system. The CNN directly detects and decodes license plates without requiring intermediate segmentation steps, eliminating the fragility of rule-based methods while maintaining character recognition accuracy through learned feature patterns.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent merges the segmentation and recognition steps into a single integrated CNN detection process. Instead of separate segmentation followed by OCR, the network performs both functions simultaneously through holistic pattern recognition, improving reliability by eliminating error propagation between stages and maintaining precision through joint optimization of detection and decoding.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If traditional OCR methods are used for character identification, then measurement precision is improved, but ease of operation deteriorates

Engineering Contradiction:
Improvecharacter recognition accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent combines multiple traditional processing stages (detection, segmentation, OCR) into a single CNN-based detection and decoding system. This integration simplifies the operational workflow by eliminating manual parameter tuning and multi-step processing while maintaining recognition accuracy through the network's learned features, making the system easier to operate without sacrificing precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The CNN system performs automatic detection and decoding without requiring manual intervention for parameter adjustment or preprocessing. The network self-adapts to different license plate formats and conditions through its training, eliminating the need for operators to configure segmentation parameters or adjust OCR settings, thereby improving ease of operation while maintaining measurement precision through automated optimization.

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS10963719B1Optimized vehicle license plate recognition
Publication Date: 2021.03.30 CCC INTELLIGENT SOLUTIONS INC
  • US10963719B1 patent drawing
  • US10963719B1 patent drawing
  • US10963719B1 patent drawing

AI summary

Techniques for optimizing vehicle license plate recognition in images and their decoding include training a set of convolutional neural networks (CNNs) by using images in which license plates are identified or labeled as a whole, rather than by license plate parts or key points, and rather than by the individual, segmented characters represented thereon. The trained CNNs may operate on target images of environments to localize images of license plates included therein and determine the issuing jurisdiction and/or ordered set of characters represented on detected license plates without utilizing character segmentation and/or per-character recognition techniques. As such, license plates depicted within target images are able to be detected and decoded with greater tolerances for lighting conditions, deformations or damages, occlusions, differing image resolutions, differing angles of capture, variations of other objects depicted within the images (such as dense or changing signage), etc.