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Posted 13 Jan 2015

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How To Do Simple Image Binarization?

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13 Jan 2015CPOL
How to do simple image binarization?

Sample Image - maximum width is 600 pixels

Introduction

Sometimes, we need to transform color images to monochrome image. There is one way that it is very simple to help you to do. You can download source code and binary files. Even I refer to OpenCV book, but I think it is so easy. I decide to implement it by myself.

Background

Equipment Operation System: Microsoft Windows 7 Professional (64 bit) Development Utility: Microsoft Visual Studio 2010.

Using the Code

C++
// The height of the image.
for ( int iY = 0; iY < imageA->DibInfo->bmiHeader.biHeight; iY++ )
{
    // The width of the image.
    for ( int iX = 0; iX < imageA->DibInfo->bmiHeader.biWidth; iX++ )
    {
        // The index of pixel, because we use the three depth bit to present one pixel of color,
        // Therefore, we have to multiple three.
        lIDXA = ( iX * 3 ) + ( iY * imageA->DibInfo->bmiHeader.biWidth * 3 );
        // To get the pixel depth of the blue channel,
        byteRGB_BA = imageA->DibArry[lIDXA+0];
        // To get the pixel depth of the green channel.
        byteRGB_GA = imageA->DibArry[lIDXA+1];
        // To get the pixel depth of the red channel.
        byteRGB_RA = imageA->DibArry[lIDXA+2];
        // To transform RGB to Y (gray scale).
        dobYUV_YA =  (0.299 * byteRGB_RA + 0.587 * byteRGB_GA + 0.114 * byteRGB_BA);
        // Set our thresholds, To decide which pixel become to white. 
        if ( dobYUV_YA > 60 && dobYUV_YA < 160 )
        {
            lIDXB = ( iX * 3 ) + ( iY * imageB->DibInfo->bmiHeader.biWidth * 3 );
            imageB->DibArry[lIDXB+0] = 255;
            imageB->DibArry[lIDXB+1] = 255;
            imageB->DibArry[lIDXB+2] = 255;
        }
        // Otherwise, those pixels will be black.
        else
        {
            lIDXB = ( iX * 3 ) + ( iY * imageB->DibInfo->bmiHeader.biWidth * 3 );
            imageB->DibArry[lIDXB+0] = 0;
            imageB->DibArry[lIDXB+1] = 0;
            imageB->DibArry[lIDXB+2] = 0;
        }
    } // for ( int iX = 0; iX < imageA->DibInfo->bmiHeader.biWidth; iX++ )
} // for ( int iY = 0; iY < imageA->DibInfo->bmiHeader.biHeight; iY++ )

Exception

  1. There is a notice, if your bit depth of bitmap file is not 24 bits, you should change your bitmap files to adapt this program, or you could rewrite this source code to fit your bitmap format.
  2. You have to install Microsoft SDK v7.1, because I include windowscodes.lib.
    C++
    #pragma comment(lib, "windowscodecs.lib")

Reference

  • [1] Gary Bradski and Adrian Kaehler, “Learning OpenCV: Computer Vision with the OpenCV Library,” O’REILLY, September 2008, ISBN:978-0-596-51613-0

Acknowledgement

Thank you (Microsoft Visual Studio 2010, Lenna Sjööblom) very much for this great development utility and beautiful photo.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

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About the Author

Lai Taiyu
Instructor / Trainer GJun Information Co.,Ltd.
Taiwan Taiwan
Dr. Lai Tai-Yu received the Ph.D. from National Taipei University of Technology in 2016. He is the co-author of 2 journal, 25 conference papers, 6 books, 9 articles in the codeproject.com, and 2 patents inventions. His research interests lie in the areas of digital image processing and AI. He is a lecturer.  

Dr Taiyu Lai. Stopień doktora, uzyskał w 2016 roku i objął stanowisko adiunkta na Wydziale. Ponadto jest autorem i współautorem: 2 publikacji artykułu w czasopiśmie naukowym, 25 artykułów opublikowanych w materiałach konferencyjnych, 6 książek, 9 eseje w monografiach codeproject.com, i posiada dwa patenty. Zainteresowania naukowe: przetwarzania obrazów i AI. Jest wykładowcą.  

赖岱佑在2016年取得台北科技大学资讯工程博士学位,有2篇期刊、25篇会议论文、6本书籍、9篇文章在 codeproject.com 、2项专利。研究方向:数字图像处理和AI。现职是一位讲师。

賴岱佑在2016年取得台北科技大學資訊工程博士學位,有2篇期刊、25篇會議論文、6本書籍、9篇文章在 codeproject.com 、2項專利。研究方向:數位影像處理和AI。現職是一位講師。

Comments and Discussions

 
QuestionQuick color conversion using fixed point arithmetics Pin
Kochise16-Jan-15 5:07
MemberKochise16-Jan-15 5:07 
AnswerRe: Quick color conversion using fixed point arithmetics Pin
Lai Taiyu18-Jan-15 14:43
professionalLai Taiyu18-Jan-15 14:43 
GeneralNice job! Pin
Alexander Golde14-Jan-15 9:49
MemberAlexander Golde14-Jan-15 9:49 
Are you intereressed in how to do that in a dataflow program ?

Check this video on YouTube : [^]

Best regards
Alex

modified 15-Jan-15 4:12am.

GeneralRe: Nice job! Pin
Lai Taiyu18-Jan-15 14:38
professionalLai Taiyu18-Jan-15 14:38 
GeneralRe: Nice job! Pin
Alexander Golde18-Jan-15 21:03
MemberAlexander Golde18-Jan-15 21:03 
GeneralRe: Nice job! Pin
Lai Taiyu19-Jan-15 12:58
professionalLai Taiyu19-Jan-15 12:58 
GeneralRe: Nice job! Pin
Alexander Golde21-Jan-15 3:15
MemberAlexander Golde21-Jan-15 3:15 
QuestionAbout the implementation ... Pin
Amarnath S14-Jan-15 3:14
professionalAmarnath S14-Jan-15 3:14 
AnswerRe: About the implementation ... Pin
Lai Taiyu18-Jan-15 14:35
professionalLai Taiyu18-Jan-15 14:35 

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