Document Scanning from ASP.net Web Application - asp.net

Question

I have a ASP.Net C# 4.0 Web Application
I need to Add a scanning feature for my users.
This is what I want to achieve
On my web application
user clicks on a button
opens a window with preview of document in Scanning device attached to the client system
User confirms the Scan
this will save the Scanned document in jpg/pdf format on the server
then do the OCR on document
Can any one suggest a way to achieve this.
I read about this https://www.leadtools.com/sdk/engine/imaging not sure how much this can work. Can any one suggest a best way to get this done.
Thanks
update
tried leadtools from https://www.leadtools.com/support/forum/posts/m28036-Re--Scan-and-Upload-v16--NET-with-Caspol-exe-deployment as LEAD Support suggested but it is missing references not sure where and how to get those references

Answer 1

HaBo,
This is LEAD support. Since you mentioned our LEADTOOLS toolkit, the answer to your question is yes. Our toolkit can be used to implement either of the 2 approaches mentioned by tgolisch.
For the click-once approach, you simply use our Windows Forms controls that contain Twain support and package your application for ClickOnce deployment. This is done, for example, in this demo project:
LEADTOOLS ClickOnce Demos
For the custom control approach, see the example code projects on our forums that perform Scan and Upload

Answer 2

Solution is here:
In ASP.Net/Core Project you send message to call winform project:
var start = function () {
var i = 0;
var wsImpl = window.WebSocket || window.MozWebSocket;
window.ws = new wsImpl('ws://localhost:8181/');
ws.onmessage = function (e) {
$('#submit').hide();
$('#scanBtn').hide();
$('.loader').show();
if (typeof e.data === "string") {
//IF Received Data is String
}
else if (e.data instanceof ArrayBuffer) {
//IF Received Data is ArrayBuffer
}
else if (e.data instanceof Blob) {
i++;
var f = e.data;
f.name = "File" + i;
storedFiles.push(f);
formdata.append(f.name, f);
var reader = new FileReader();
reader.onload = function (e) {
var html = "<div class=\"col-sm-2 text-center\"
style=\"border: 1px solid black; margin-left: 2px;\"><img
height=\"200px\" width=\"200px\" src=\"" + e.target.result + "\"
data-file='" + f.name + "' class='selFile' title='Click to
remove'><br/>" + i + "</div>";
selDiv.append(html);
$('#submit').show();
$('#scanBtn').show();
$('.loader').hide();
}
reader.readAsDataURL(f);
}
};
ws.onopen = function () {
//Do whatever u want when connected succesfully
};
ws.onclose = function () {
$('.dalert').modal('show');
};
}
window.onload = start;
function scanImage() {
ws.send("1100");
};
https://javascript.info/websocket
In Winforms Project you scan document and send graphic data back to Asp.Net/Core project:
public partial class Form1 : Form
{
ImageCodecInfo _tiffCodecInfo;
TwainSession _twain;
bool _stopScan;
bool _loadingCaps;
List allSockets;
WebSocketServer server;
public Form1()
{
InitializeComponent();
if (NTwain.PlatformInfo.Current.IsApp64Bit)
{
Text = Text + " (64bit)";
}
else
{
Text = Text + " (32bit)";
}
foreach (var enc in ImageCodecInfo.GetImageEncoders())
{
if (enc.MimeType == "image/tiff") { _tiffCodecInfo = enc; break; }
}
this.WindowState = FormWindowState.Minimized;
this.ShowInTaskbar = false;
allSockets = new List<IWebSocketConnection>();
server = new WebSocketServer("ws://0.0.0.0:8181");
server.Start(socket =>
{
socket.OnOpen = () =>
{
Console.WriteLine("Open!");
allSockets.Add(socket);
};
socket.OnClose = () =>
{
Console.WriteLine("Close!");
allSockets.Remove(socket);
};
socket.OnMessage = message =>
{
if (message == "1100")
{
this.Invoke(new Action(()=> {
this.WindowState = FormWindowState.Normal;
}));
}
};
});
}
Link to project.
https://github.com/mgriit/ScanAppForWeb
You can remake this project, as you want.

Answer 3

Web browsers don't have permissions to use system devices like this(major security issue). There are 2 common ways of getting around this:
Make a custom control to run in your browser (flash, silverlight, java applet).
Make a "click-once deployment app" that a user launches from your page.
Both approaches would send the data back to your server via web
services or WCF, etc.