How to acquire the top part of page from TWAIN/SANE scanner?
In This Topic
If you want to set the scan area for TWAIN or SANE scanner, please use the
WebTwainDeviceJS.setImageLayout function.
Also TWAIN scanner allows to set the scan area using the
WebTwainDeviceJS.setCapability function.
Here is JavaScript code that demonstrates how to use WebDeviceJS.setImageLayout function for acquiring image area from TWAIN/SANE scanner:
// acquire top part of page from TWAIN/SANE scanner
__acquireTopPartOfPageFromTwainScanner();
/**
* Acquires top part of page from TWAIN/SANE scanner.
*/
function __acquireTopPartOfPageFromTwainScanner() {
// register the evaluation version of VintaSoft Web TWAIN service
// please read how to get evaluation license in documentation: https://www.vintasoft.com/docs/vstwain-dotnet-web/Licensing-Twain_Web-Evaluation.html
Vintasoft.Twain.WebTwainGlobalSettingsJS.register('REG_USER', 'REG_URL', 'REG_CODE', 'EXPIRATION_DATE');
// URL to the VintaSoft Web TWAIN service
var serviceUrl = 'https://localhost:25329/api/VintasoftTwainApi';
// a Web API controller that allows to work with TWAIN and SANE devices
var twainService = new Vintasoft.Shared.WebServiceControllerJS(serviceUrl);
// TWAIN/SANE device manager
var deviceManager = new Vintasoft.Twain.WebTwainDeviceManagerJS(twainService);
// the default settings of device manager
var deviceManagerInitSetting = new Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS();
var device = null;
try {
// open device manager
deviceManager.open(deviceManagerInitSetting);
// get the default TWAIN/SANE device
device = deviceManager.get_DefaultDevice();
// open device without UI
device.open(false);
// if device is TWAIN device
if (device.get_DeviceName().substring(0, 5) == "Twain") {
// set the inches as unit of measure
device.set_UnitOfMeasure(new Vintasoft.Twain.WebUnitOfMeasureEnumJS("Inches"));
}
// get current image layout
let imageLayout: Vintasoft.Twain.WebTwainImageLayoutJS = device.getImageLayout();
// set the image layout (get only the top half of the page)
device.setImageLayout(0, 0, imageLayout.get_Width(), imageLayout.get_Height() / 2);
// a collection that stores images, which are acquired from TWAIN/SANE devices and stored in memory of VintaSoft Web TWAIN service
var acquiredImages = new Vintasoft.Twain.WebAcquiredImageCollectionJS(deviceManager);
var acquireModalState;
do {
// do one step of modal image acquisition process
var acquireModalResult = device.acquireModalSync();
// get state of image acquisition
acquireModalState = acquireModalResult.get_AcquireModalState().valueOf();
switch (acquireModalState) {
case 2: // image is acquired
// get acquired image
var acquiredImage = acquireModalResult.get_AcquiredImage();
// add acquired image to the image collection
acquiredImages.add(acquiredImage);
// get image as Base64 string
var bitmapAsBase64String = acquiredImage.getAsBase64String();
// update image preview
var previewImageElement = document.getElementById('previewImage');
previewImageElement.src = bitmapAsBase64String;
// clear image collection (delete images from memory of VintaSoft Web TWAIN service) because image is not necessary anymore
acquiredImages.clear();
break;
case 4: // image scan is failed
alert(acquireModalResult.get_ErrorMessage());
break;
case 9: // image scan is finished
break;
}
}
while (acquireModalState !== 0);
}
catch (ex) {
alert(ex);
}
finally {
if (device != null) {
// close the device
device.close();
}
// close the device manager
deviceManager.close();
}
}
Here is TypeScript code that demonstrates how to use WebDeviceJS.setImageLayout function for acquiring image area from TWAIN/SANE scanner:
import { Component } from '@angular/core';
@Component({
selector: 'twain-scanning-demo',
templateUrl: './twain-scanning-demo.component.html'
})
export class TwainScanningDemoComponent {
ngOnInit() {
// acquire top part of page from TWAIN/SANE scanner
this.__acquireTopPartOfPageFromTwainScanner();
}
/**
* Acquires top part of page from TWAIN/SANE scanner.
*/
__acquireTopPartOfPageFromTwainScanner() {
// register the evaluation version of VintaSoft Web TWAIN service
// please read how to get evaluation license in documentation: https://www.vintasoft.com/docs/vstwain-dotnet-web/Licensing-Twain_Web-Evaluation.html
Vintasoft.Twain.WebTwainGlobalSettingsJS.register('REG_USER', 'REG_URL', 'REG_CODE', 'EXPIRATION_DATE');
// URL to the VintaSoft Web TWAIN service
let serviceUrl: string = 'https://localhost:25329/api/VintasoftTwainApi';
// a Web API controller that allows to work with TWAIN and SANE devices
let twainService: Vintasoft.Shared.WebServiceControllerJS = new Vintasoft.Shared.WebServiceControllerJS(serviceUrl);
// TWAIN/SANE device manager
let deviceManager: Vintasoft.Twain.WebTwainDeviceManagerJS = new Vintasoft.Twain.WebTwainDeviceManagerJS(twainService);
// the default settings of device manager
let deviceManagerInitSetting: Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS = new Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS();
try {
// open device manager
deviceManager.open(deviceManagerInitSetting);
}
catch (ex) {
alert(ex);
return;
}
let device: Vintasoft.Twain.WebTwainDeviceJS = null;
try {
// get the default TWAIN/SANE device
device = deviceManager.get_DefaultDevice();
// open device without UI
device.open(false);
// if device is TWAIN device
if (device.get_DeviceName().substring(0, 5) == "Twain") {
// set the inches as unit of measure
device.set_UnitOfMeasure(new Vintasoft.Twain.WebUnitOfMeasureEnumJS("Inches"));
}
// get current image layout
let imageLayout: Vintasoft.Twain.WebTwainImageLayoutJS = device.getImageLayout();
// set the image layout (get only the top half of the page)
device.setImageLayout(0, 0, imageLayout.get_Width(), imageLayout.get_Height() / 2);
// a collection that stores images, which are acquired from TWAIN/SANE devices and stored in memory of VintaSoft Web TWAIN service
let acquiredImages: Vintasoft.Twain.WebAcquiredImageCollectionJS = new Vintasoft.Twain.WebAcquiredImageCollectionJS(deviceManager);
let acquireModalState: number;
do {
// do one step of modal image acquisition process
let acquireModalResult: Vintasoft.Twain.WebTwainDeviceAcquireModalResultJS = device.acquireModalSync();
// get state of image acquisition
acquireModalState = acquireModalResult.get_AcquireModalState().valueOf() as number;
switch (acquireModalState) {
case 2: // image is acquired
// get acquired image
let acquiredImage: Vintasoft.Twain.WebAcquiredImageJS = acquireModalResult.get_AcquiredImage();
// add acquired image to the image collection
acquiredImages.add(acquiredImage);
// get image as Base64 string
let bitmapAsBase64String: string = acquiredImage.getAsBase64String();
// update image preview
let previewImageElement: HTMLImageElement = document.getElementById('previewImage') as HTMLImageElement;
previewImageElement.src = bitmapAsBase64String;
// clear image collection (delete images from memory of VintaSoft Web TWAIN service) because image is not necessary anymore
acquiredImages.clear();
break;
case 4: // image scan is failed
alert(acquireModalResult.get_ErrorMessage());
break;
case 9: // image scan is finished
break;
}
}
while (acquireModalState !== 0);
}
catch (ex) {
alert(ex);
}
finally {
if (device != null) {
// close the device
device.close();
}
// close the device manager
deviceManager.close();
}
}
}
Here is TypeScript code that demonstrates how to use WebDeviceJS.setCapability function for acquiring image area from TWAIN/SANE scanner:
// acquire top part of page from TWAIN scanner
__acquireTopPartOfPageFromTwainScanner();
/**
* Acquires top part of page from TWAIN scanner.
*/
function __acquireTopPartOfPageFromTwainScanner() {
// register the evaluation version of VintaSoft Web TWAIN service
// please read how to get evaluation license in documentation: https://www.vintasoft.com/docs/vstwain-dotnet-web/Licensing-Twain_Web-Evaluation.html
Vintasoft.Twain.WebTwainGlobalSettingsJS.register('REG_USER', 'REG_URL', 'REG_CODE', 'EXPIRATION_DATE');
// URL to the VintaSoft Web TWAIN service
var serviceUrl = 'https://localhost:25329/api/VintasoftTwainApi';
// a Web API controller that allows to work with TWAIN and SANE devices
var twainService = new Vintasoft.Shared.WebServiceControllerJS(serviceUrl);
// TWAIN device manager
var deviceManager = new Vintasoft.Twain.WebTwainDeviceManagerJS(twainService);
// the default settings of device manager
var deviceManagerInitSetting = new Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS();
var device = null;
try {
// open device manager
deviceManager.open(deviceManagerInitSetting);
// get the default TWAIN device
device = deviceManager.get_DefaultDevice();
// open device without UI
device.open(false);
// set the inches as unit of measure
device.set_UnitOfMeasure(new Vintasoft.Twain.WebUnitOfMeasureEnumJS("Inches"));
// set the image layout rectangle as value of IFrames capability
device.setCapability(new Vintasoft.Twain.WebDeviceCapabilityIdEnumJS("IFrames"), new Vintasoft.Twain.WebTwainFrameJS(0, 0, 2, 2));
// a collection that stores images, which are acquired from TWAIN/SANE devices and stored in memory of VintaSoft Web TWAIN service
var acquiredImages = new Vintasoft.Twain.WebAcquiredImageCollectionJS(deviceManager);
var acquireModalState;
do {
// do one step of modal image acquisition process
var acquireModalResult = device.acquireModalSync();
// get state of image acquisition
acquireModalState = acquireModalResult.get_AcquireModalState().valueOf();
switch (acquireModalState) {
case 2: // image is acquired
// get acquired image
var acquiredImage = acquireModalResult.get_AcquiredImage();
// add acquired image to the image collection
acquiredImages.add(acquiredImage);
// get image as Base64 string
var bitmapAsBase64String = acquiredImage.getAsBase64String();
// update image preview
var previewImageElement = document.getElementById('previewImage');
previewImageElement.src = bitmapAsBase64String;
// clear image collection (delete images from memory of VintaSoft Web TWAIN service) because image is not necessary anymore
acquiredImages.clear();
break;
case 4: // image scan is failed
alert(acquireModalResult.get_ErrorMessage());
break;
case 9: // image scan is finished
break;
}
}
while (acquireModalState !== 0);
}
catch (ex) {
alert(ex);
}
finally {
if (device != null) {
// close the device
device.close();
}
// close the device manager
deviceManager.close();
}
}
Here is TypeScript code that demonstrates how to use WebDeviceJS.setCapability function for acquiring image area from TWAIN/SANE scanner:
import { Component } from '@angular/core';
@Component({
selector: 'twain-scanning-demo',
templateUrl: './twain-scanning-demo.component.html'
})
export class TwainScanningDemoComponent {
ngOnInit() {
// acquire top part of page from TWAIN scanner
this.__acquireTopPartOfPageFromTwainScanner();
}
/**
* Acquires top part of page from TWAIN scanner.
*/
__acquireTopPartOfPageFromTwainScanner() {
// register the evaluation version of VintaSoft Web TWAIN service
// please read how to get evaluation license in documentation: https://www.vintasoft.com/docs/vstwain-dotnet-web/Licensing-Twain_Web-Evaluation.html
Vintasoft.Twain.WebTwainGlobalSettingsJS.register('REG_USER', 'REG_URL', 'REG_CODE', 'EXPIRATION_DATE');
// URL to the VintaSoft Web TWAIN service
let serviceUrl: string = 'https://localhost:25329/api/VintasoftTwainApi';
// a Web API controller that allows to work with TWAIN and SANE devices
let twainService: Vintasoft.Shared.WebServiceControllerJS = new Vintasoft.Shared.WebServiceControllerJS(serviceUrl);
// TWAIN device manager
let deviceManager: Vintasoft.Twain.WebTwainDeviceManagerJS = new Vintasoft.Twain.WebTwainDeviceManagerJS(twainService);
// the default settings of device manager
let deviceManagerInitSetting: Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS = new Vintasoft.Twain.WebTwainDeviceManagerInitSettingsJS();
try {
// open device manager
deviceManager.open(deviceManagerInitSetting);
}
catch (ex) {
alert(ex);
return;
}
let device: Vintasoft.Twain.WebTwainDeviceJS = null;
try {
// get the default TWAIN device
device = deviceManager.get_DefaultDevice();
// open device without UI
device.open(false);
// set the inches as unit of measure
device.set_UnitOfMeasure(new Vintasoft.Twain.WebUnitOfMeasureEnumJS("Inches"));
// set the image layout rectangle as value of IFrames capability
device.setCapability(new Vintasoft.Twain.WebDeviceCapabilityIdEnumJS("IFrames"), new Vintasoft.Twain.WebTwainFrameJS(0, 0, 2, 2));
// a collection that stores images, which are acquired from TWAIN/SANE devices and stored in memory of VintaSoft Web TWAIN service
let acquiredImages: Vintasoft.Twain.WebAcquiredImageCollectionJS = new Vintasoft.Twain.WebAcquiredImageCollectionJS(deviceManager);
let acquireModalState: number;
do {
// do one step of modal image acquisition process
let acquireModalResult: Vintasoft.Twain.WebTwainDeviceAcquireModalResultJS = device.acquireModalSync();
// get state of image acquisition
acquireModalState = acquireModalResult.get_AcquireModalState().valueOf() as number;
switch (acquireModalState) {
case 2: // image is acquired
// get acquired image
let acquiredImage: Vintasoft.Twain.WebAcquiredImageJS = acquireModalResult.get_AcquiredImage();
// add acquired image to the image collection
acquiredImages.add(acquiredImage);
// get image as Base64 string
let bitmapAsBase64String: string = acquiredImage.getAsBase64String();
// update image preview
let previewImageElement: HTMLImageElement = document.getElementById('previewImage') as HTMLImageElement;
previewImageElement.src = bitmapAsBase64String;
// clear image collection (delete images from memory of VintaSoft Web TWAIN service) because image is not necessary anymore
acquiredImages.clear();
break;
case 4: // image scan is failed
alert(acquireModalResult.get_ErrorMessage());
break;
case 9: // image scan is finished
break;
}
}
while (acquireModalState !== 0);
}
catch (ex) {
alert(ex);
}
finally {
if (device != null) {
// close the device
device.close();
}
// close the device manager
deviceManager.close();
}
}
}