In the past two weeks, I trained a custom YOLOv3 model for QR code detection and tested it with Darknet. In this article, I will use OpenCV’s DNN (Deep Neural Network) module to load the YOLO model for making detection from static images and real-time camera video stream. Besides, I will use Dynamsoft Barcode Reader to decode QR codes from the regions detected by YOLO.Read more
A dot code is a 2D barcode symbology composed of disconnected dots. It is widely used in the tobacco industry. Recently, Dynamsoft rolled out barcode reader SDK v7.4, which added DotCode support. In this post, I will share a command-line app and a GUI app, demonstrating how to build Java DotCode reader on Windows 10.Read more
OpenCV is written in C++. If you install OpenCV library on Windows, you will see OpenCV officially provides wrappers for Python and Java but not for C#. Fortunately, there are many .NET open source projects for wrapping OpenCV C++ APIs, and thus we don’t need to write a wrapper from scratch. In this post, I will share how to use OpenCV library and Dynamsoft Barcode Reader SDK to create a .NET barcode reader app on Windows.
Document Scanning is nothing new for mobile apps. I remember the first time that I installed a document scanning app was in 2010. However, Apple, Microsoft, and Google the giant tech companies got started to recognize the importance of document scanning technology recently. It is good to see the function appears in iOS Notes, Office Lens and Google Drive. Why is the document scanning being hot now? I think the reason is the quality of images captured by mobile cameras is getting better and better. More and more users tend to scan documents with cameras instead of traditional scanners. If you are not familiar with Android and iOS development, you can use HTML5. In this post, I will share how to create a simple web document management app using OpenCV.js.
Many excellent document mobile apps support not only image capture, but also edge detection and perspective transformation. If you are interested in these computer vision technologies, you can use OpenCV to create a free document scanner app yourself. In this post, I want to share how to use OpenCV-Python to create a web document scanner step by step.
Recently, I was inspired by a blog post “Python Live Video Streaming Example” and thinking whether it is possible to save the camera streaming to a video file. Based on the example code, I managed to figure out a solution. In this post, I want to share the process of building the web camera recorder using OpenCV and Flask.
Using OpenCV APIs to capture video from a camera is convenient. However, OpenCV does not provide an API for listing all available devices. If you have multiple cameras connected to your PC, you have no idea how to choose the right one. To get device information on Windows, you need to invoke DirectShow APIs. In this post, I will share how to create a Python extension that lists camera devices for OpenCV-Python on Windows.
This article is about how to use OpenCV and Dynamsoft Barcode Reader SDK to create a Python barcode reader on macOS.
Previously, I wrote an article Raspberry Pi Barcode Scanner with Webcam and Python illustrating how to build a simple barcode scanner using Dynamsoft Barcode Reader SDK and OpenCV from scratch. The method decodeFile() was used for detecting barcodes from an image file. To use the API, you have to write image buffer that obtained by OpenCV API to a file beforehand. Because the I/O operation takes too much time, this API is not suitable for real-time barcode detection from webcam video stream. Considering this scenario, I have added a new Python API decodeBuffer(). In this article, I will illustrate how to create and use the new API.
OpenCV officially provides both C++ and Python APIs for developers. Most of the time, developers just need to use one kind of programming languages to read, write and process images with hundreds of computer vision algorithms. However, if you want to use OpenCV Python APIs with an extended C/C++ library, it will be tricky to pass the data. In this article, I will share how to read camera stream with OpenCV-Python and detect barcode with Dynamsoft C/C++ Barcode SDK.