Testing JPG -> MagickWand -> raw buffer -> MagickWand -> JPG

test.cpp

#include <wand/magick_wand.h>
#include <iostream>
#include <vector>

using namespace std;

int main(int argc, char* argv[])
{
    MagickWand *mw_in = NewMagickWand();
    MagickWand *mw_out = NewMagickWand();

    MagickWandGenesis();

    MagickReadImage(mw_in, argc > 1 ? argv[1] : "logo:");

    cout << "Image type: " << MagickGetImageType(mw_in) << endl;
    cout << "#images: " << MagickGetNumberImages(mw_in) << endl;
    cout << "Alpha channel: " << MagickGetImageAlphaChannel(mw_in) << endl;
    cout << "Colorspace: " << MagickGetImageColorspace(mw_in) << endl;
    cout << "Depth: " << MagickGetImageDepth(mw_in) << endl;

    const ssize_t x = 0, y = 0, cols = MagickGetImageWidth(mw_in), rows = MagickGetImageHeight(mw_in);
    const StorageType st = CharPixel;
    std::vector<unsigned char> buf(3*cols*rows);
    cout << "Export result: " << MagickExportImagePixels(mw_in, x, y, cols, rows, "RGB", st, &buf[0]) << endl;

    cout << "Constitute result: " << MagickConstituteImage(mw_out, cols, rows, "RGB", CharPixel, &buf[0]) << endl;
    cout << "Set colspace result: " << MagickSetImageColorspace(mw_out, RGBColorspace) << endl;
    cout << "Set image depth result: " << MagickSetImageDepth(mw_out, 8) << endl;
    MagickResetIterator(mw_out);

    MagickWriteImage(mw_out, "logo.jpg");

    if(mw_in) mw_in = DestroyMagickWand(mw_in);
    if(mw_out) mw_out = DestroyMagickWand(mw_out);

    MagickWandTerminus();

    return 0;
}