How to Use Gamma Correction for Image Processing with Opencv

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 will introduce Gamma Correction and show you how to use it with OpenCV.

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How to Build ImageMagick for Software Distribution on Windows

If you have read the article How to Benchmark Barcode SDK Performance – ZXing vs ZBar, you may have noticed that ZBar relies on ImageMagick. ImageMagick is an open source software suite that capable of reading a variety of images. If you just want to write a barcode testing program, Windows Binary Release of ImageMagick is enough. However, if you consider distributing your applications, the Windows binary distribution is not suitable. Why? I’ll show you in the following content.

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OpenCV Edge Detection

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 to make image edge detection with OpenCV.

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Making PHP Barcode Extension with Dynamsoft Barcode SDK

After writing articles talking about how to wrap Dynamsoft Barcode SDK to make Barcode extensions for Java, Python and JavaScript, I started to consider PHP. It is one of the most popular tags on StackOverflow. Most Web developers prefer using PHP for server-side development. Since PHP allows developers to write extensions in C/C++, I was going to create a PHP Barcode extension with Dynamsoft Barcode Reader SDK. However, the whole process was not as easy as I expected. In this post, I’d like to share what troubles I’ve got and what solutions I’ve found.

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How to Make Java Barcode Reader with Dynamsoft Barcode SDK

Last week, Dynamsoft released Barcode Reader (DBR) SDK v2.0, which is available for Windows and Mac. The Windows installer contains Barcode libraries for ActiveX, C/C++, and .NET. If you are a Java developer, you have to use JNI to link native C/C++ libraries. In this tutorial, I’ll demonstrate how to invoke the native methods of Dynamsoft Barcode SDK via JNI to create a Java Barcode Reader.

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Building OpenCV with CMake on Windows

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 source code is on GitHub, let’s get the copy and build the source code ourselves for fun.

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