Published Aug 04, 2023
Written By Glenn Fernandes
Computer vision, a branch of artificial intelligence, focuses on teaching computers to interpret and understand visual data like images and videos. One application of computer vision technology is Automatic License Plate Recognition (ALPR). ALPR systems use computer vision algorithms to capture and analyze license plate information from images or video streams. This technology has numerous applications, including law enforcement, traffic control, and vehicle access management.
Building a computer vision ALPR product comes with its fair share of challenges. Let’s explore some of the key technical hurdles that developers often encounter and must overcome:
Computer vision algorithms require significant computational power, making GPU acceleration a necessity. However, configuring CUDA, GPU drivers, libraries, and dependencies can be a complex task, often leading developers to dive into a realm known as “configuration hell.” Ensuring compatibility and resolving compatibility issues with various software components can be time-consuming and frustrating.
Successfully navigating this maze using tools like docker, anaconda and package managers is an essential step in developing a robust ALPR system.
Tracking objects, especially in real-time scenarios, can be a daunting task in ALPR systems. Objects can be occluded (partially hidden) or move swiftly, making it challenging to accurately identify and track license plates.
Developers must employ sophisticated algorithms, such as Kalman filtering and deep learning-based object tracking ( DEEPSORT ), to handle occlusion and maintain high-speed and accurate tracking. OpenCV provides a few tracking algorithms as part of its legacy interface with varying performances based on their use case.
ALPR systems very likely need to track information other than just the license plate. These include vehicle color, make, model, type, and sometimes speed.
They are expected to accurately detect vehicle colors, even in varying lighting conditions throughout the day. Different lighting conditions, such as bright daylight, low light, or artificial lighting, can alter the appearance of license plate colors. This challenge requires implementing color normalization and adaptive thresholding techniques to ensure robust color detection and consistent performance across all lighting environments.
Training a computer vision model for ALPR requires a vast amount of labeled data. Collecting and annotating this data to create a custom dataset is a labor-intensive task. Developers must carefully capture diverse license plates, in different lighting conditions, from various angles and distances, to ensure a robust and versatile model. This process can be time-consuming and requires significant effort to generate a dataset that accurately represents real-world scenarios.
Building a scalable and reliable ALPR system is crucial, especially in scenarios where large volumes of vehicles are expected. The system must handle and process numerous video feeds simultaneously while maintaining real-time performance and accuracy. Achieving this requires optimizing algorithms and models, leveraging parallel processing techniques, updating and upgrading models, and designing a distributed architecture that can scale horizontally when needed.
Building a computer vision ALPR product presents numerous technical challenges. From configuring complex software dependencies to handling occlusion, lighting variations, scalability, reliable object tracking, and generating custom datasets, developers must strategize and implement solutions meticulously. Overcoming these challenges is essential for delivering a high-performing, accurate, and robust ALPR system. By understanding and addressing these obstacles, developers can pave the way for the successful deployment of ALPR technology in diverse real-world applications.
Remember, overcoming these challenges demands both technical expertise and continuous learning to stay abreast of the latest advancements in computer vision and ALPR technologies. With determination and perseverance, developers can develop cutting-edge ALPR solutions that contribute to safer, more efficient communities.