Tag: opencv
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Handheld camera devices play a big part in the document scanning process as they are more portable, powerful and affordable. However, different from using a document scanner, using a camera imposes challenges like complex backgrounds, variations in light, and perspective distortions. Thus, it is necessary to use a document scanning...
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Object detection is a computer technology related to computer vision and image processing that deals with detecting instances of semantic objects of a certain class (such as humans, buildings, or cars) in digital images and videos.1 It can be used in a barcode reading task as barcodes are often printed...
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Whether we scan documents via document scanners or cameras, we may end up getting document images with bad quality. In this article, we are going to talk about how to evaluate the quality of scanned document images so that we can recapture the document to get a better image. A...
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OpenCV is an open-source computer vision and machine learning software library. It provides various image processing methods for us to solve different tasks. In this article, we are going to build a web document scanner with the JavaScript version of OpenCV. A JavaScript library is made first and then used...
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OpenCV is an open-source computer vision and machine learning software library and has a basic barcode reading ability. It has a QR Code detector added in 2018 and a barcode detector added in 2021 which supports detecting and decoding of EAN-13, EAN-8, and UPC-A barcodes. It has a JavaScript version...
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Scanned documents often contain skewed or crooked images. They do not look good and are not friendly for OCR. In this article, we are going to use OpenCV and Python to deskew scanned documents based on text lines. Steps to Deskew a Scanned Document Image with OpenCV We are going...
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QR codes are a critical part of modern applications — from payment systems and ticketing to inventory management and document tracking. As a two-dimensional barcode, a QR code can store significantly more data than a 1D barcode and is decoded from a camera image using image processing algorithms. Choosing the...
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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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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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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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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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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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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...