How to specifiy dimensions for scanning in ASP.NET MVC + HTML5 (using Local Service)

Questions, comments and suggestions concerning VintaSoft Twain .NET SDK.

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varalonga
Posts: 1
Joined: Mon Dec 18, 2017 10:49 pm

How to specifiy dimensions for scanning in ASP.NET MVC + HTML5 (using Local Service)

Post by varalonga » Wed Jan 10, 2018 3:10 pm

Hi,


I'm having some troubles so I thought I could reach you guys for some help.
I've been using theTWAIN .NET SDK product on a ASP.NET MVC project using the
ASP.NET MVC + HTML5 approach (using Local Service) and I'm having some troubles with
the scanning process.
If I choose to scan using the Scanner native UI, I have always the preview tool and I always
have the chance to define the scan area. Our scanner allows to scan documents up to A3 size.
Still, when I try to scan documents withou the scanner UI, it seems that the documents are
always scanned in the A4 portrait size; therefore if I try to scan a document in A4 landscape
or A3, it will always end up being cropped.
I've noticed in the online documentation (e.g., https://www.vintasoft.com/docs/vstwain- ... _Disk.html) these two lines of code:

' set the inches as unit of measure
device.UnitOfMeasure = UnitOfMeasure.Inches
' set the desired resolution of acquired images
device.Resolution = New Resolution(300.0F, 300.0F)

Using the ASP.NET MVC + HTML5 approach is there any way of specifying these same properties
(or any other way) in javascript?
Thanks in advance.


kind regards,

Vítor Varalonga
Ciberbit, S.A.

Alex
Site Admin
Posts: 1564
Joined: Thu Jul 10, 2008 2:21 pm

Re: How to specifiy dimensions for scanning in ASP.NET MVC + HTML5 (using Local Service)

Post by Alex » Wed Jan 10, 2018 5:08 pm

Hello Vítor,

You can get the capability value using the WebTwainDeviceJS.getDeviceCapability function, please see example here:
https://www.vintasoft.com/docs/vstwain- ... ility.html

You can set the capability value using the WebTwainDeviceJS.setDeviceCapability function, please see example here:
https://www.vintasoft.com/docs/vstwain- ... ility.html

For setting the unit of measure and image resolution you need to use the following JavaScript code:

Code: Select all

function setUnitOfMeasureAndResolution(openedDevice, unitOfMeasure, resX, resY) {
    // success callback
    function __success(data) {
        // capability
        var capability = data.capability;
        // new value of capability
        var newValue = capability.currentValue.value;
        // log information about new value
        console.log("Capability '" + capability.name + "' new value - " + newValue);
    }

    // error callback
    function __error(data) {
        // message
        var message = "";
        // if capability exists
        if (data.capability != undefined)
            // add information about capability name
            message += "Capability '" + data.capability.name + "':";
        // add information about error
        message += data.errorMessage;
        // show message
        alert(message);
    }

    // change unit of measure
    openedDevice.setCapability(new Vintasoft.Twain.WebDeviceCapabilityIdJS("IUnits"), unitOfMeasure, __success, __error);
    // change horizontal resolution
    openedDevice.setCapability(new Vintasoft.Twain.WebDeviceCapabilityIdJS("IXResolution"), resX, __success, __error);
    // change vertical resolution
    openedDevice.setCapability(new Vintasoft.Twain.WebDeviceCapabilityIdJS("IYResolution"), resY, __success, __error);
}
Also please see code of Twain Device Capabilities dialog in source codes of AspNetMvc5Demos project:
"[InstallPath]\VintaSoft Imaging .NET v8.6\Examples\CSharp\AspNetMvc5Demos\Scripts\UI\Dialogs\Twain\twainDeviceCapabilitiesDialog.js"

Best regards, Alexander

LutherCo
Posts: 1
Joined: Tue Jan 16, 2018 1:09 pm

Re: How to specifiy dimensions for scanning in ASP.NET MVC + HTML5 (using Local Service)

Post by LutherCo » Wed Jan 24, 2018 7:38 pm

Hi Alex, I can't seem to set the capability value. When I do what is described, nothing happens. Any idea what my problem may be?

Alex
Site Admin
Posts: 1564
Joined: Thu Jul 10, 2008 2:21 pm

Re: How to specifiy dimensions for scanning in ASP.NET MVC + HTML5 (using Local Service)

Post by Alex » Thu Jan 25, 2018 9:35 am

Hello,
LutherCo wrote:
Wed Jan 24, 2018 7:38 pm
I can't seem to set the capability value. When I do what is described, nothing happens. Any idea what my problem may be?
I have updated the example in previous post. Also we added example to documentation: https://www.vintasoft.com/docs/vstwain- ... ility.html

Please see the example, try to use it in your code and let me know if you will have any question or problem.

Best regards, Alexander

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