Re: [AGG] Bitmap resolution

[Analist <in...@an...>]

Hi McSeem,

1) I load an image, example 300 dpi with this code:
BOOL CAggBuffer::LoadBmp(CString csFile)
{
ASSERT(!csFile.IsEmpty());
 agg::pixel_map pmap_tmp;
    if(!pmap_tmp.load_from_bmp(csFile)) return false;

 m_dImageWidht  = pmap_tmp.width();
 m_dImageHeight = pmap_tmp.height();

 agg::rendering_buffer rbuf_tmp;
        rbuf_tmp.attach(pmap_tmp.buf(),
                        pmap_tmp.width(),
                        pmap_tmp.height(),
                        m_flip_y ?
                          pmap_tmp.stride() :
                         -pmap_tmp.stride());

        m_pmap_img.create(pmap_tmp.width(),
                               pmap_tmp.height(),
          agg::org_e(m_bpp),
                               0);

        m_rbuf_window.attach(m_pmap_img.buf(),
                    m_pmap_img.width(),
                    m_pmap_img.height(),
                    m_flip_y ?
                       m_pmap_img.stride() :
                      -m_pmap_img.stride());

  FitToImageSize(m_dImageWidht,m_dImageHeight);

        switch(m_format)
        {
        case agg::pix_format_gray8:
            switch(pmap_tmp.bpp())
            {
            //case 16: agg::color_conv(&m_rbuf_window, &rbuf_tmp, 
color_conv_rgb555_to_gray8()); break;
            case 24: agg::color_conv(&m_rbuf_window, &rbuf_tmp, 
agg::color_conv_bgr24_to_gray8()); break;
            //case 32: agg::color_conv(&m_rbuf_window, &rbuf_tmp, 
color_conv_bgra32_to_gray8()); break;
            }
            break;

   case agg::pix_format_gray16:
.................
.................

3) I process it with:
   typedef agg::span_interpolator_persp_exact<> interpolator_type;

   typedef agg::span_subdiv_adaptor<interpolator_type> subdiv_adaptor_type;
   typedef agg::image_accessor_clone<pixfmt> source_type;

   interpolator_type interpolator(m_quad.polygon(), g_x1, g_y1, g_x2, g_y2);
   subdiv_adaptor_type subdiv_adaptor(interpolator);

   if(interpolator.is_valid() /*&& 1==2*/)
   {
    typedef image_resample_type<source_type, subdiv_adaptor_type> 
span_gen_type;

    span_gen_type sg(source, subdiv_adaptor, filter);
    sg.blur(1);
    agg::render_scanlines_aa(g_rasterizer, g_scanline, m_ElabBuff.m_rb, sa, 
sg);
   }
   m_bTransform = FALSE;


3) I save the buffer with : m_pmap_window.save_as_bmp

4) The resulting image is 72 dpi


Antonio


"Maxim Shemanarev" <mcs...@ya...> ha scritto nel messaggio 
news:200...@we......
> Can you explain it more? What do you use to load and save images?
>
>> Hello,
>>
>> How is possible not to lose bitmap resolution during processing?
>> For example if I load a 300 dpi image after processing and saving I 
>> obtain a
>> 70 dpi image.
>>
>> Regards
>> Antonio
>>