Tag: TWAIN

Document Scanning on Linux with SANE and JavaScript

Xiao Ling /  / TWAIN / , ,

Dynamic Web TWAIN SDK is a scanning SDK designed for web application development. It helps developers to easily build document scanning apps with a few lines of JavaScript code. The preview of Dynamic Web TWAIN for Linux is available now. In this post, I will demonstrate how to configure a USB scanner, as well as how to run the online demo of Dynamic Web TWAIN on Ubuntu.

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How to Run Web TWAIN App on Nginx within Docker Container

Xiao Ling /  / Docker / , , ,

Dynamic Web TWAIN (DWT) is a Web-based TWAIN scanning solution, which could be deployed to Windows, Mac OS X, and Linux. Users could visit DWT apps via any HTML5-comptible Web browsers on Windows or Mac. To facilitate the process of Web project deployment, we can use Docker. In this post, I’m going to demo how to build a Web TWAIN docker image, and how to run the Web TWAIN “hello world” with commands in one line.

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How to Push Notifications to Android Applications from Windows

Xiao Ling /  / Android / ,

When you are scanning tons of documents with your scanner applications, probably you don’t have enough time to take a break sometimes. Because you need to stare at the screen for checking all scanning information in case of some errors. Fortunately, mobile applications can help us reduce the burden. No matter where we are, using a smartphone as the monitor is a convenient way to deal with some emergencies. In this tutorial, I’d like to share how to create an Android application for receiving notifications from a .NET scanner application which is implemented based on Dynamic .NET TWAIN.

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Wireless TWAIN Document Scanning on Android

Xiao Ling /  / Android / , 3 comments

If you have a TWAIN-compliant scanner, you can easily control it with Dynamic Web TWAIN or Dynamic .NET TWAIN. Both SDKs can help you create some excellent applications for document scanning and management on PCs. However, have you ever complained that it’s so inconvenient to stay with your scanners and PCs all the time? Since mobile technology is so hot today, why don’t you make TWAIN scan wireless, getting rid of clumsy machines? In this tutorial, I’d like to show you how to create a simple Android application and a .Net TWAIN server to conveniently capture document images from remote TWAIN scanners to your smartphone.

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Barcode Generator with HTML5 WebSocket

Xiao Ling /  / HTML5 / , , ,

Last week, I shared how to transmit an image between a WebSocket server and a Web client. Based on that, we can make a little bit of improvement. Today, I would like to share how to generate barcode on .Net server side and display it on web browser.

websocket barcode

Prerequisites

Remote Barcode Generator

  • In your WinForms project, add DynamicBarcode.dll and set its property Copy to Output Directory as Copy always. As so, the Dynamic .NET TWAIN component is able to automatically load the barcode library.

barcode library

  • Encode the received message, and draw generated barcode onto a background image:
            float scale = 3;
            short sImageIndex = 0;
            dynamicDotNetTwain.MaxImagesInBuffer = 1;
            bool isLoaded = dynamicDotNetTwain.LoadImage("test.png");
            dynamicDotNetTwain.AddBarcode(sImageIndex, Dynamsoft.DotNet.TWAIN.Enums.Barcode.BarcodeFormat.QR_CODE, message, "", 0, 0, scale);
  • Send image width, height and data to web client:
            Image img = dynamicDotNetTwain.GetImage(sImageIndex);

            ImageData imageData = load_image(img);
            session.Send(imageData.Width + "," + imageData.Height);
            session.Send(imageData.Data, 0, imageData.Data.Length);
            imageData = null;
  • Display the barcode image on JavaScript web client:
               ws.onmessage = function (evt) {
                    var data = evt.data;
                    if (!data)
                        return;

                    if (data instanceof ArrayBuffer) {
                        drawImage(evt.data);
                    }
                    else {
                        var len = data.length;
                        var index = data.indexOf(",");
                        var w = data.substring(0, index);
                        var h = data.substring(index + 1, len);
                        imageWidth = parseInt(w);
                        imageHeight = parseInt(h);
                    }
                };

Now, you can have fun with the remote barcode generator via all browsers (Chrome, Firefox, IE etc.) which support HTML5 WebSocket.

Source Code

WebSocketBarcodeGenerator