Re: [Boost-users] [gil io_new] Problem writing a compressed jpeg

Subject: Re: [Boost-users] [gil io_new] Problem writing a compressed jpeg
From: Olivier Tournaire (olitour_at_[hidden])
Date: 2010-06-07 11:12:36

Hi Christian,

2010/6/2 Christian Henning <chhenning_at_[hidden]>

> Hi Olivier,
>
> >
> > The code works. However, the output image is not compressed. It has the
> same
> > size (in octets) as the  one which uses the default jpeg_tag.
>
> On my system the jpeg with quality set to 100% is 20KB, whereas the
> one with 30% for quality is only 4KB. Could you set a breakpoint in
> boost\gil\extension\io_new\formats\jpeg\write.hpp[119]? That's where
> the quality is set.
>

It finally works on one of my computer ... but on another one, I get a
compilation error. Here is the (long) message :

/usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp: In
function ‘typename Op::result_type
boost::gil::detail::apply_operation_base(Bits&, size_t, const Info&, Op)
[with Types =
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb16_pixel_t*>
> >,
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*>
> >, boost::mpl::vector0<mpl_::na>, 0>, 0>, Info =
boost::gil::image_write_info<boost::gil::jpeg_tag,
boost::gil::detail::no_log>, Bits =
boost::gil::variant<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb16_pixel_t*>
> >,
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*>
> >, boost::mpl::vector0<mpl_::na>, 0>, 0> >::base_t, Op =
boost::gil::detail::dynamic_io_fnobj<boost::gil::detail::jpeg_write_is_supported,
boost::gil::detail::writer<boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>,
boost::gil::jpeg_tag, boost::gil::detail::no_log> >]’:

/usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:269:
*instantiated
from ‘typename BinaryOp::result_type
boost::gil::detail::apply_**operation*(const
boost::gil::variant<Types>&, const Info&, BinaryOp) [with Types1 =
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb16_pixel_t*>
> >,
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*>
> >, boost::mpl::vector0<mpl_::na>, 0>, 0>, Info =
boost::gil::image_write_info<boost::gil::jpeg_tag,
boost::gil::detail::no_log>, BinaryOp =
boost::gil::detail::dynamic_io_fnobj<boost::gil::detail::jpeg_write_is_supported,
boost::gil::detail::writer<boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>,
boost::gil::jpeg_tag, boost::gil::detail::no_log> >]’

/usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:309:
instantiated from ‘void boost::gil::detail::dynamic_image_writer<Device,
boost::gil::jpeg_tag, boost::gil::detail::no_log>::apply(const
boost::gil::any_image_view<Views>&, const
boost::gil::image_write_info<boost::gil::jpeg_tag,
boost::gil::detail::no_log>&) [with Views =
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb16_pixel_t*>
> >,
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*>
> >, boost::mpl::vector0<mpl_::na>, 0>, 0>, Device =
boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>]’

/usr/local/include/boost/gil/extension/io_new/detail/write_view.hpp:302:
*instantiated
from ‘void boost::gil::write_view*(Device&, const
boost::gil::any_image_view<Types2>&, const
boost::gil::image_write_info<FormatTag, Log>&, typename
boost::enable_if<typename boost::mpl::and_<typename
boost::gil::detail::is_output_device<IODevice>::type, typename
boost::gil::is_format_tag<FormatTag>::type, mpl_::bool_<true>,
mpl_::bool_<true>, mpl_::bool_<true> >::type, void>::type*) [with Device =
boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>, Views =
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb16_pixel_t*>
> >,
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*>
> >, boost::mpl::vector0<mpl_::na>, 0>, 0>, FormatTag =
boost::gil::jpeg_tag, Log = boost::gil::detail::no_log]’

/usr/local/include/boost/gil/extension/io_new/detail/write_view.hpp:357:
*instantiated
from ‘void boost::gil::write_view*(const String&, const
boost::gil::any_image_view<Types2>&, const
boost::gil::image_write_info<FormatTag, Log>&, typename
boost::enable_if<typename boost::mpl::and_<typename
boost::gil::detail::is_supported_path_spec<P>::type, typename
boost::gil::is_format_tag<FormatTag>::type, mpl_::bool_<true>,
mpl_::bool_<true>, mpl_::bool_<true> >::type, void>::type*) [with String =
const char*, Views =
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb16_pixel_t*>
> >,
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*>
> >, boost::mpl::vector0<mpl_::na>, 0>, 0>, FormatTag =
boost::gil::jpeg_tag, Log = boost::gil::detail::no_log]’

/home/olivier/work/dev/OTO_DEV/projects/tif2jpeg_for_itowns_viewer/main_tif2jpeg_for_itowns_viewer.cpp:43:
instantiated from here

/usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:244:
*error:
no matching function for call to ‘boost::gil::detail::apply_**
operation_fwd_fn<2ul>::apply*(boost::gil::variant<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb16_pixel_t*>
> >,
boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*>
> >, boost::mpl::vector0<mpl_::na>, 0>, 0> >::base_t&, size_t&, const
boost::gil::image_write_info<boost::gil::jpeg_tag,
boost::gil::detail::no_log>&,
boost::gil::detail::dynamic_io_fnobj<boost::gil::detail::jpeg_write_is_supported,
boost::gil::detail::writer<boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>,
boost::gil::jpeg_tag, boost::gil::detail::no_log> >&)’

/usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:244:
*error:
return-statement with a value, in function returning 'void'*

If I comment the info parameter on line 242 of formats/jpeg/write.hpp, the
compilation error disappears, but, the infos are not passed to the writer,
what explain why my image is not compressed (the parameters are set to their
default values). Could you please help on how to fix this error?
I am on a linux ubuntu karmic koala, boost 1.42, libjpeg 6.2, g++ 4.3.4

Best regards,

Olivier

> >>
> >> BTW, you can pass strings into the io_new interface. No need for
> >> c_str(). Also the jpeg_dct_method::fastest parameter works just fine.
> >
> > Could yo please also tell me more about this parameter?
>
> The dct parameter stands for discrete cosine transformation and it's
> for selecting the appropriate method to do that transformation. In
> some cases those calculation can be quite expensive.
>
> Regards,
> Christian
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