Tag: opencv
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Dynamsoft is the only company that provides enterprise-class Python Barcode and QR Code SDK for Windows, Linux, macOS, and Raspberry Pi OS. The SDK allows developers to quickly build robust command-line, web, and desktop applications that can scan barcodes and QR codes from a wide range of sources. In this...
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There are many open source JavaScript barcode and QR code reader libraries, but few of them are suitable for enterprise use. The reason is that they do not have a road map for long-term algorithm updates and maintenance. In addition, the performance of pure JavaScript is not good enough. WebAssembly...
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“WebP is an image format employing both lossy and lossless compression, and supports animation and alpha transparency. Developed by Google, it is designed to create files that are smaller for the same quality, or of higher quality for the same size, than JPEG, PNG, and GIF image formats” - Wikipedia....
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When using a QR code reader or scanner SDK, we primarily focus on the detection speed and recognition accuracy. There are many factors that may affect the performance of the QR code detection SDK. The factors can be approximately classified into two categories: image quality and algorithm performance. In this...
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The International Article Number (also known as European Article Number or EAN) is a standard describing a barcode symbology and numbering system used in global trade to identify a specific retail product type. The most commonly used EAN standard is the thirteen-digit EAN-13. 1 The 13-digit EAN-13 number consists of...
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Motion detection can detect whether there is a change in the positions of objects. It can be achieved by many methods. For example, infrared light or laser technology can be used for optical detection. As for image processing methods, there is a basic one by a fixed camera, which compares...
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The accuracy of optical character recognition (OCR) is sensitive to text orientation. If a text image file is rotated by 90°, 180° or 270°, and there is no EXIF information, it would be challenging to doing text recognition. In case of text around barcode, the combination of Dynamsoft Label Recognition(DLR)...
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Dynamsoft Label Recognition (DLR) is an OCR SDK implemented in C/C++. The 1.0 Beta version was recently rolled out for Windows and Linux platforms. This article will demonstrate how to utilize the APIs of Dynamsoft Label Recognition to create a text recognition app on Windows. Requirements Dynamsoft Label Recognition 1.0...
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While scanning single or multiple barcodes with a barcode SDK, most of the developers only concern about the trade-off between decoding speed and recognition accuracy, for they cannot get other data. Since from version 8.0, Dynamsoft exposes more parameters and intermediate results (E.g., grayscale image, binary image, barcode localization results,...
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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...
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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...
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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...
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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...
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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...
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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...
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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...
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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,...
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Dynamsoft Barcode Reader C++ SDK is available for Windows, Linux, and Mac (iOS and Android editions are coming soon). I have shared an article that illustrates how to build webcam barcode reader in Python. In this tutorial, I’ll use a different C++ API to implement barcode scanner applications for Windows...
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In reality, we can always see some photos that have low brightnesses and low contrast. To make objects recognizable in pictures, we need to process the photo with Illumination Compensation. There are many algorithms used for Illumination Compensation such as Histogram equalization, Color similarity measure, Gamma Correction and so on. In this tutorial, I...
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In this tutorial, let’s see how easy to find all contours in an image with OpenCV APIs. Overview Finding contours is a useful task during image processing. The relevant OpenCV functions are as follows: Find contours in a binary image. void findContours(InputOutputArray image, OutputArrayOfArrays contours, OutputArray hierarchy, int mode, int...
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In this tutorial, let’s learn how to use Hough line transformation with OpenCV to make line detection in an Image. Hough Line Transform The Hough Line Transform is a transform used to detect straight lines. OpenCV implements three kinds of Hough Line Transforms:(Standard Hough Transform, SHT),(Multi-Scale Hough Transform, MSHT)and (Progressive...
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Changes or discontinuities of amplitude attribute, such as luminance value, are fundamentally important primitive characteristics of an image. They often provide an indication of the physical extent of objects. Local Discontinuities of image luminance that from one level to another are called luminance edges. In this post, I’ll share how...
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OpenCV (Open Source Computer Vision Library) is a powerful open source library of computer vision algorithms. It is widely used by many technologies, such as image acquiring (e.g. Webcam capture), image processing (e.g. noise reduction), image detection (e.g. face detection), image recognition (e.g. OCR), and so on. Since all OpenCV...