User Guide for C++ Language

In this guide, you will learn step by step on how to build a document normalization application with Dynamsoft Document Normalizer SDK using C++ language.

Requirements

Operating System:
- Windows 7, 8, 10, 11
- Windows Server 2003, 2008, 2008 R2, 2012, 2016, 2019, 2022
- Linux x64: Ubuntu 14.04.4+ LTS, Debian 8+, etc
Developing Tool
- Visual Studio 2008 or above
- G++ 5.4+

Installation

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

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

Build Your First Application

Let’s start by creating a console application which demonstrates how to use the minimum code to detect and normalize document from an image file.

You can download the entire source code from here.

Create a New Project

For Windows

Open Visual Studio. Go to File > New > Project, create a new Empty Project and set Project name as DDNCPPSample.
Add a new source file named DDNCPPSample.cpp into the project.

For Linux

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

Include the Library

Add headers and libs in DDNCPPSample.cpp.

 #include <iostream>
 #include "[INSTALLATION FOLDER]/Include/DynamsoftDocumentNormalizer.h"
 using namespace std;
 using namespace dynamsoft::ddn;
 using namespace dynamsoft::core;
 #if defined(_WIN64) || defined(_WIN32)
     #ifdef _WIN64
         #pragma comment(lib, "[INSTALLATION FOLDER]/Lib/Windows/x64/DynamsoftCorex64.lib")
         #pragma comment(lib, "[INSTALLATION FOLDER]/Lib/Windows/x64/DynamsoftDocumentNormalizerx64.lib")
     #else
         #pragma comment(lib, "[INSTALLATION FOLDER]/Lib/Windows/x86/DynamsoftCorex86.lib")
         #pragma comment(lib, "[INSTALLATION FOLDER]/Lib/Windows/x86/DynamsoftDocumentNormalizerx86.lib")
     #endif
 #endif

Initialize a Document Normalizer Instance

Initialize the license key.
```
 char szErrorMsg[256];
 CLicenseManager::InitLicense("DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9", szErrorMsg, 256);
```
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 trial license via the Request a Trial License link.
Create an instance of Dynamsoft Document Normalizer.
```
 CDocumentNormalizer ddn;
```

Detect and Save the Normalized Document

Apply normalization for an image file.
```
 int errorCode = 0;
 CNormalizedImageResult* normalizedResult = NULL;
 errorCode = ddn.Normalize("[INSTALLATION FOLDER]/Images/sample-image.png", "", NULL, &normalizedResult);
 if(errorCode != DM_OK)
     cout << DC_GetErrorString(errorCode) << endl;
```
For the error handling mechanism, the SDK returns Error Code for each function and provides a function DC_GetErrorString to get the readable message. You should add codes for error handling based on your needs. Check out Error Code for full supported error codes.

Save the normalized result as an image file.

 if (normalizedResult != NULL)
 {
     CDocumentNormalizer::SaveImageDataToFile(normalizedResult->image, "result-image.png");
 }

Release Allocated Memory

Release the allocated memory for the normalized result and instance.

 if (normalizedResult != NULL)
     CDocumentNormalizer::FreeNormalizedImageResult(&normalizedResult);

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

Build and Run the Project

For Windows

In Visual Studio, set the solution to build as Release|x64.
Build the project to generate program DDNCPPSample.exe.
Copy ALL *.dll files under [INSTALLATION FOLDER]\Lib\Windows\x64 to the same folder as the DDNCPPSample.exe.
Run the program DDNCPPSample.exe.

The SDK supports both x86 and x64, please set the platform based on your needs.

For Linux

Open a terminal and change to the target directory where DDNCPPSample.cpp located in. Build the sample:

 g++ -o DDNCPPSample DDNCPPSample.cpp -lDynamsoftCore -lDynamsoftDocumentNormalizer -L ../Lib/Linux -Wl,-rpath=../Lib/Linux -std=c++11

Run the program DDNCPPSample.
```
 ./DDNCPPSample
```

You can download the entire source code from here.