ByteScout Barcode Reader SDK – C++ (Unmanaged) – Set Image Preprocessing Filters

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ByteScout Barcode Reader SDK – C++ (Unmanaged) – Set Image Preprocessing Filters

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ByteScout-BarCode-Reader-SDK-C-plus-plus-(Unmanaged)-Set-Image-Preprocessing-Filters.pdf

How to set image preprocessing filters in C++ (Unmanaged) and ByteScout BarCode Reader SDK

How to code in C++ (Unmanaged) to set image preprocessing filters with this step-by-step tutorial

We made thousands of pre-made source code pieces for easy implementation in your own programming projects. Want to set image preprocessing filters in your C++ (Unmanaged) app? ByteScout BarCode Reader SDK is designed for it. ByteScout BarCode Reader SDK is the barcode decoder with support for code 39, code 128, QR Code, Datamatrix, GS1, PDF417 and all other popular barcodes. Can read barcodes from images, pdf, tiff documents and live web camera. Supports noisy and damaged documents, can split and merge pdf and tiff documents based on barcodes. Can export barcode decoder results to XML, JSON, CSV and into custom data structures.

The SDK samples like this one below explain how to quickly make your application do set image preprocessing filters in C++ (Unmanaged) with the help of ByteScout BarCode Reader SDK. This C++ (Unmanaged) sample code is all you need for your app. Just copy and paste the code, add references (if needs to) and you are all set! Enjoy writing a code with ready-to-use sample codes in C++ (Unmanaged).

Free trial version of ByteScout BarCode Reader SDK is available for download from our website. Get it to try other source code samples for C++ (Unmanaged).

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ImagePreprocessingFilters.cpp

      #include "stdafx.h"

///
/// This example demonstrates the use of image filters to improve the decoding confidence or speed.
///

#import "c:\\Program Files\\Bytescout BarCode Reader SDK\\net2.00\\Bytescout.BarCodeReader.tlb" raw_interfaces_only

using namespace Bytescout_BarCodeReader;

void PrintFoundBarcodes(IReaderPtr pIReader);

int _tmain(int argc, _TCHAR* argv[])
{
	// Initialize COM.
	HRESULT hr = CoInitialize(NULL);

	// Create the interface pointer.
	IReaderPtr pIReader(__uuidof(Reader));

	// set the registration name and key
	_bstr_t registrationName(L"DEMO");
	pIReader->put_RegistrationName(registrationName);

	_bstr_t registrationKey(L"DEMO");
	pIReader->put_RegistrationKey(registrationKey);

	// Set barcode type to find
	_BarcodeTypeSelectorPtr pBarcodeTypesToFind;
	pIReader->get_BarcodeTypesToFind(&pBarcodeTypesToFind);
	pBarcodeTypesToFind->put_Code128(VARIANT_TRUE);

	
	// Get image filters collection
	_ImagePreprocessingFiltersCollection* pIImageFilters;
	pIReader->get_ImagePreprocessingFilters(&pIImageFilters);

	
	// WORKING WITH LOW CONTRAST BARCODE IMAGES

	pIImageFilters->AddContrast(40);

	// Add contrast adjustment for low-contrast image
	_bstr_t sampleFile1(L".\\low-contrast-barcode.png");	
	wprintf(L"Image \"%s\"\n", static_cast<wchar_t*>(sampleFile1));

	pIReader->ReadFromFile(sampleFile1);
	PrintFoundBarcodes(pIReader);

	pIImageFilters->Clear();


	// WORKING WITH NOISY BARCODE IMAGES

	// Add median filter to lower a noise
	pIImageFilters->AddMedian();

	_bstr_t sampleFile2(L".\\noisy-barcode.png");
	wprintf(L"Image \"%s\"\n", static_cast<wchar_t*>(sampleFile2));

	pIReader->ReadFromFile(sampleFile2);
	PrintFoundBarcodes(pIReader);

	pIImageFilters->Clear();


	// WORKING WITH DENSE AND ILLEGIBLE BARCODES

	// Add the scale filter to enlarge the barcode to make gaps between bars more distinguishable
	pIImageFilters->AddScale_2(2.0);

	_bstr_t sampleFile3(L".\\too-dense-barcode.png");
	wprintf(L"Image \"%s\"\n", static_cast<wchar_t*>(sampleFile3));

	pIReader->ReadFromFile(sampleFile3);
	PrintFoundBarcodes(pIReader);

	pIImageFilters->Clear();


	// REMOVE EMPTY MARGINS FROM IMAGE TO SPEED UP THE PROCESSING

	// Add the crop filter to cut off empty margins from the image.
	// This will not improve the recognition quality but may speed up the processing 
	// if you enabled multiple barcode types to search. 
	pIImageFilters->AddCropDark();

	_bstr_t sampleFile4(L".\\barcode-with-large-margins.png");
	wprintf(L"Image \"%s\"\n", static_cast<wchar_t*>(sampleFile4));

	pIReader->ReadFromFile(sampleFile4);
	PrintFoundBarcodes(pIReader);

	pIImageFilters->Clear();


	
	// Uninitialize COM.
	CoUninitialize();

	// Wait until user press any key
	system("pause");

	return 0;
}

void PrintFoundBarcodes(IReaderPtr pIReader)
{
	// Get found barcode count
	long count;
	pIReader->get_FoundCount(&count);

	// Get found barcode information
	for (int i = 0; i < count; i++)
	{
		SymbologyType type;
		pIReader->GetFoundBarcodeType(i, &type);
		wprintf(L"Barcode type: %d\n", type);

		float confidence;
		pIReader->GetFoundBarcodeConfidence(i, &confidence);
		wprintf(L"Barcode confidence: %f\n", confidence);

		BSTR bstrValue;
		pIReader->GetFoundBarcodeValue(i, &bstrValue);
		wprintf(L"Barcode value: %s\n", bstrValue);
		::SysFreeString(bstrValue);

		wprintf(L"\n");
	}

	if (count == 0)
	{
		wprintf(L"No barcodes found.\n");
	}
}

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stdafx.cpp

      // stdafx.cpp : source file that includes just the standard includes
// CPPExample.pch will be the pre-compiled header
// stdafx.obj will contain the pre-compiled type information

#include "stdafx.h"

// TODO: reference any additional headers you need in STDAFX.H
// and not in this file

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stdafx.h

      // stdafx.h : include file for standard system include files,
// or project specific include files that are used frequently, but
// are changed infrequently
//

#pragma once

#include "targetver.h"

#include <stdio.h>
#include <tchar.h>



// TODO: reference additional headers your program requires here

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targetver.h

      #pragma once

// Including SDKDDKVer.h defines the highest available Windows platform.

// If you wish to build your application for a previous Windows platform, include WinSDKVer.h and
// set the _WIN32_WINNT macro to the platform you wish to support before including SDKDDKVer.h.

#include <SDKDDKVer.h>