void GUIMyFrame1::m_b_prewitt_click( wxCommandEvent& event )
{
    wxSize m_size = Img_Org.GetSize();
    const int width = m_size.GetWidth();
    const int height = m_size.GetHeight();
    unsigned char* org_data = Img_Org.GetData();
    unsigned char* cpy_data = (unsigned char*)malloc(width * height * 3 * sizeof(unsigned char));
    int ver, hor;

    for (int y = 1; y < height - 1; ++y)
    {
        for (int x = 1; x < width - 1; ++x)
        {
            for (int off = 0; off < 3; ++off)
            {
                ver = org_data[3 * ((y - 1) * width + (x - 1)) + off];
                ver += org_data[3 * (y * width + (x - 1)) + off];
                ver += org_data[3 * ((y + 1) * width + (x - 1)) + off];
                ver -= org_data[3 * ((y - 1) * width + (x + 1)) + off];
                ver -= org_data[3 * (y * width + (x + 1)) + off];
                ver -= org_data[3 * ((y + 1) * width + (x + 1)) + off];

                if (ver > 255) ver = 255;
                else if (ver < 0) ver = 0;

                hor = org_data[3 * ((y - 1) * width + (x - 1)) + off];
                hor += org_data[3 * ((y - 1) * width + x) + off];
                hor += org_data[3 * ((y - 1) * width + (x + 1)) + off];
                hor -= org_data[3 * ((y + 1) * width + (x + 1)) + off];
                hor -= org_data[3 * ((y + 1) * width + x) + off];
                hor -= org_data[3 * ((y + 1) * width + (x - 1)) + off];

                if (hor > 255) hor = 255;
                else if (hor < 0) hor = 0;

                cpy_data[3 * (y * width + x) + off] = sqrt(ver * ver + hor * hor);
            }
        }
    }

    Img_Cpy.Create(m_size, cpy_data);
    Repaint();
}