Re: [Boost-users] [GIL] read/write jpeg image from/to a buffer, not a file

Hi all, On Wed, Jul 25, 2018 at 2:56 PM Mateusz Loskot via Boost-users < boost-users@lists.boost.org> wrote:

On 18 July 2018 at 15:05, Frédéric via Boost-users wrote:

...

Hi,

Is it possible to read/write an image as JPEG from/into a memory buffer instead of a file?

I assume you mean using something like a stringstream as an in-memory buffer. The test suite has some examples, like: BOOST_AUTO_TEST_CASE( stream_test ) { // 1. Read an image. std::ifstream in( jpeg_filename.c_str(), ios::binary ); rgb8_image_t img; read_image( in, img, tag_t() ); // 2. Write image to in-memory buffer. std::stringstream out_buffer( ios_base::in | ios_base::out | ios_base::binary ); write_view( out_buffer, view( img ), tag_t() ); // 3. Copy in-memory buffer to another. std::stringstream in_buffer( ios_base::in | ios_base::out | ios_base::binary ); in_buffer << out_buffer.rdbuf(); // 4. Read in-memory buffer to gil image rgb8_image_t dst; read_image( in_buffer, dst, tag_t() ); // 5. Write out image. std::string filename( jpeg_out + "stream_test.jpg" ); std::ofstream out( filename.c_str(), ios_base::binary ); write_view( out, view( dst ), tag_t() ); } Does that help? Regards, Christian​