Question

I have written the following structures.

struct RGB
{
     unsigned short Red; 
     unsigned short Green;
     unsigned short Blue;
};

struct ImageBase
{
     std::string name;
     RGB array[64][64];
};

I have got a file “Image.png”.How do I read the file(print the RGB values to the screen or file)?

Answer 1

You could use gil which is part of boost to read the image:

using namespace boost::gil;
rgb8_image_t input;
png_read_and_convert_image(ipath, input);

You would then create a view on the image to access the pixels, and iterate over the pixels to write them to standard out:

rgb8_view_t src_view = view(input);

for (int y=0; y < src_view.height(); ++y) {

    rgb8_view_t::x_iterator src_it = src_view.row_begin(y);

    for (int x=0; x < src_view.width(); ++x)
        std::cout << "R=" << src_it[x][0] << " G=" << src_it[x][1] << " B=" << src_it[x][2] << std::endl;
}

Docs for gil are here: http://www.boost.org/doc/libs/1_51_0/libs/gil/doc/index.html