WhiteThresholdImage magick

Question

how to use WhiteThresholdImage with magick++ ?

I search for it and i found for solutions and so i try:

#include <Magick++.h>  
using namespace Magick;  

int main()  
{  
    Magick::InitializeMagick("");  
    Image image;  
    image.read("logo.jpg");  
    char* threshold = 20;  
    MagickLib::WhiteThresholdImage(image, threshold);  
}  

error: cannot convert ‘Magick::Image’ to ‘MagickLib::Image* {aka MagickLib::_Image*}’ for argument ‘1’ to ‘unsigned int MagickLib::WhiteThresholdImage(MagickLib::Image*, const char*)’

    #include   
    using namespace Magick;  

    int main()  
    {  
        Magick::InitializeMagick("");  
        Image image;  
        image.read("logo.jpg");  
        char* threshold = 20;  
        WhiteThresholdImage(image, threshold);  
    }  

error: ‘WhiteThresholdImage’ was not declared in this scope

Answer 1

You are mixing the C API with the C++ API and they can't be mixed like that.

The WhiteThresholdImage() function is not exposed via Magick++. However, the quantumOperator() method can do the same thing (and much more). The following will white-threshold pixels over 20% of the numeric range to white:

image.quantumOperator(AllChannels, ThresholdWhiteQuantumOp, 0.20*MaxRGB);