User Guide for Document Scanner with C++

In this guide, you will learn step by step on how to build a document scanner solution with Dynamsoft Capture Vision SDK using c++.

Table of Contents

User Guide for Document Scanner with C++

System Requirements

To find out whether your environment is supported, please read the System Requirements.

Installation

If you haven’t downloaded the SDK yet, download the C/C++ Package now and unpack the package into a directory of your choice.

For this tutorial, we unpack it to a pseudo directory [INSTALLATION FOLDER], change it to your unpacking path for the following content.

Build Your Own Application

In this section, we’ll walk through the key steps needed to build an application that capture a document from an image file.

You can download the complete source code from here.

Create A New Project

For Windows

Open Visual Studio. Go to File > New > Project, select Empty App and enter DocumentScanner in the name text box.
Add a new source file named DocumentScanner.cpp into the project.

For Linux

Create a new source file named DocumentScanner.cpp and place it into the folder [INSTALLATION FOLDER]\Samples\DocumentScanner.

Create a file named Makefile and put it in the same directory as the file DocumentScanner.cpp. The content of Makefile is as follows:

 CC=gcc
 CCFLAGS=-c -std=c++11

 DS_LIB_PATH=[INSTALLATION FOLDER]/Distributables/Lib/Linux/x64
 LDFLAGS=-L $(DS_LIB_PATH) -Wl,-rpath=$(DS_LIB_PATH) -Wl,-rpath=./
 DS_LIB=-lDynamsoftCaptureVisionRouter -lDynamsoftCore -lDynamsoftLicense -lDynamsoftUtility
 DS_JSON_PATH=[INSTALLATION FOLDER]/Distributables/Templates

 STDLIB=-lstdc++

 TARGET=DocumentScanner
 OBJECT=DocumentScanner.o
 SOURCE=DocumentScanner.cpp

 # build rule for target.
 $(TARGET): $(OBJECT)
     $(CC) -o $(TARGET) $(OBJECT) $(STDLIB) $(DS_LIB) $(LDFLAGS)
     cp -r $(DS_JSON_PATH) $(DS_LIB_PATH)

 # target to build an object file
 $(OBJECT): $(SOURCE)
     $(CC) $(CCFLAGS) $(SOURCE)

 # the clean target
 .PHONY : clean
 clean: 
     rm -f $(OBJECT) $(TARGET) -r $(DS_LIB_PATH)/Templates

Note: The variable DS_LIB_PATH should be set to the correct directory where the library files are located.

Include the Library

Add headers and libs in DocumentScanner.cpp.

 #include <iostream>
 #include <string>
 #include "[INSTALLATION FOLDER]/Include/DynamsoftCaptureVisionRouter.h"
 #include "[INSTALLATION FOLDER]/Include/DynamsoftUtility.h"

 using namespace std;
 using namespace dynamsoft::cvr;
 using namespace dynamsoft::ddn;
 using namespace dynamsoft::license;
 using namespace dynamsoft::utility;

 // The following code only applies to Windows.
 #if defined(_WIN64) || defined(_WIN32)
     #ifdef _WIN64
         #pragma comment(lib, "[INSTALLATION FOLDER]/Distributables/Lib/Windows/x64/DynamsoftCaptureVisionRouterx64.lib")
         #pragma comment(lib, "[INSTALLATION FOLDER]/Distributables/Lib/Windows/x64/DynamsoftCorex64.lib")
         #pragma comment(lib, "[INSTALLATION FOLDER]/Distributables/Lib/Windows/x64/DynamsoftLicensex64.lib")
         #pragma comment(lib, "[INSTALLATION FOLDER]/Distributables/Lib/Windows/x64/DynamsoftUtilityx64.lib")
     #else
         #pragma comment(lib, "[INSTALLATION FOLDER]/Distributables/Lib/Windows/x86/DynamsoftCaptureVisionRouterx86.lib")
         #pragma comment(lib, "[INSTALLATION FOLDER]/Distributables/Lib/Windows/x86/DynamsoftCorex86.lib")
         #pragma comment(lib, "[INSTALLATION FOLDER]/Distributables/Lib/Windows/x86/DynamsoftLicensex86.lib")
         #pragma comment(lib, "[INSTALLATION FOLDER]/Distributables/Lib/Windows/x86/DynamsoftUtilityx86.lib")
     #endif
 #endif

Initialize a Capture Vision Router Instance

Initialize the license key

 int errorcode = 0;
 char error[512];
 errorcode = CLicenseManager::InitLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9", error, 512);
 if (errorcode != ErrorCode::EC_OK && errorcode != ErrorCode::EC_LICENSE_CACHE_USED)
 {
     cout << "License initialization failed: ErrorCode: " << errorcode << ", ErrorString: " << error << endl;
 }
 else
 {
     // codes from following steps...
 }

Note: The string “DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9” here is a free public trial license. Note that network connection is required for this license to work. When it expires, you can request a 30-day free trial license from the Customer Portal.

Create an instance of Dynamsoft Capture Vision Router

 CCaptureVisionRouter* router = new CCaptureVisionRouter();

Detect and Save the Normalized Document

Apply detection and normalization for an image file.

 string imageFile = "[PATH-TO-THE-IMAGE-FILE]";
 CCapturedResult* result = router->Capture(imageFile.c_str(), CPresetTemplate::PT_DETECT_AND_NORMALIZE_DOCUMENT);

Please change the [PATH-TO-THE-IMAGE-FILE] to a real image file path.

Save the normalized result as an image file

 cout << "File: " << imageFile << endl;
 if (result->GetErrorCode() != 0) {
     cout << "Error: " << result->GetErrorCode() << "," << result->GetErrorString() << endl;
 }
 CNormalizedImagesResult *normalizedResult = result->GetNormalizedImagesResult();
 if (normalizedResult == nullptr || normalizedResult->GetItemsCount() == 0)
 {
     cout << "No document found." << endl;
 }
 else
 {
     int count = normalizedResult->GetItemsCount();
     cout << "Normalized " << count << " documents" << endl;
     for (int i = 0; i < count; i++)
     {
         const CNormalizedImageResultItem *normalizedImage = normalizedResult->GetItem(i);
         string outPath = "normalizedResult_";
         outPath += to_string(i) + ".png";
         CImageManager manager;
         errorcode = manager.SaveToFile(normalizedImage->GetImageData(), outPath.c_str());
         if (errorcode == 0)
         {
             cout << "Document " << i << " saved to file: " << outPath << endl;
         }
     }
 }

Release the Allocated Memory

if (normalizedResult)
	normalizedResult->Release();
if (result)
	result->Release();
delete router, router = NULL;   

Build and Run the Project

On Windows

Build the application through Visual Studio.
Copy the following items from [INSTALLATION FOLDER]\Distributables to the same folder as the EXE file.
- All the DLL files from .\Lib\Windows\[PLATFORMS]
- Folder Templates
Run the program DocumentScanner.exe.

On Linux

Open a terminal and change to the target directory where Makefile located in. Build the sample:
```
 >make
```
Run the program DocumentScanner.
```
 >./DocumentScanner
```

Note:

Please change all [INSTALLATION FOLDER] in above code snippet to your unpacking path.