This class write an image in a jpeg file. More...
#include <jpeg.hpp>
Classes | |
struct | destination_manager |
Destination manager that allow us to write in a std::ostream. More... | |
struct | options |
Parameters of the writing algorithm. More... | |
Public Member Functions | |
writer (const image &img) | |
Constructor. | |
writer (const image &img, std::ostream &f, const options &opt=options()) | |
Constructor. Save an image in a jpeg file. | |
void | save (std::ostream &f, const options &opt=options()) const |
Save an image in a jpeg file. | |
Private Member Functions | |
void | set_options (jpeg_compress_struct &cinfo, const options &opt) const |
Set the parameters of the JPEG saving structures. | |
void | save_image (jpeg_compress_struct &cinfo) const |
Save the image in the configured stream. | |
void | copy_pixel_line (JSAMPLE *data, unsigned int y) const |
Copy the pixels from the image to an array of bytes. | |
void | create_compress_info (jpeg_compress_struct &cinfo, destination_manager &outfile) const |
Initialize the jpeg compression structure. | |
Private Attributes | |
const image & | m_image |
The image from which we thake the data to save. | |
Static Private Attributes | |
static const unsigned int | s_rgb_pixel_size = 3 |
Size, in bytes, of a red/green/blue pixel in a jpeg file. |
This class write an image in a jpeg file.
Definition at line 167 of file jpeg.hpp.
claw::graphic::jpeg::writer::writer | ( | const image & | img | ) |
Constructor.
img | The image in which the data will be stored. |
Definition at line 168 of file jpeg_writer.cpp.
: m_image( img ) { } // jpeg::writer::writer()
claw::graphic::jpeg::writer::writer | ( | const image & | img, | |
std::ostream & | f, | |||
const options & | opt = options() | |||
) |
Constructor. Save an image in a jpeg file.
img | The image from which we read the data. | |
f | The file in which we write the data. | |
opt | Options about the saved file. |
Definition at line 182 of file jpeg_writer.cpp.
References claw::graphic::jpeg::save().
void claw::graphic::jpeg::writer::copy_pixel_line | ( | JSAMPLE * | data, | |
unsigned int | y | |||
) | const [private] |
Copy the pixels from the image to an array of bytes.
data | (out) The pixels for the JPEG image. | |
y | Index of the line of the image from which we read the pixels. |
Definition at line 295 of file jpeg_writer.cpp.
References CLAW_PRECOND.
Referenced by save_image().
{ CLAW_PRECOND( data ); CLAW_PRECOND( y < m_image.height() ); // three bytes for each pixel in the line for (unsigned int x=0; x!=m_image.width(); ++x, data+=s_rgb_pixel_size) { data[0] = m_image[y][x].components.red; data[1] = m_image[y][x].components.green; data[2] = m_image[y][x].components.blue; } } // jpeg::writer::copy_pixel_line()
void claw::graphic::jpeg::writer::create_compress_info | ( | jpeg_compress_struct & | cinfo, | |
destination_manager & | outfile | |||
) | const [private] |
Initialize the jpeg compression structure.
cinfo | The structure to initialize. | |
outfile | The destination manager. |
Definition at line 316 of file jpeg_writer.cpp.
References claw::graphic::jpeg::writer::destination_manager::pub.
Referenced by save().
{
jpeg_create_compress(&cinfo);
cinfo.dest = &outfile.pub;
cinfo.client_data = &outfile;
outfile.pub.init_destination =
claw__graphic__jpeg__destination_manager__init_destination;
outfile.pub.empty_output_buffer =
claw__graphic__jpeg__destination_manager__empty_output_buffer;
outfile.pub.term_destination =
claw__graphic__jpeg__destination_manager__term_destination;
} // jpeg::writer::create_compress_info()
Save an image in a jpeg file.
f | Jpeg file. | |
opt | Options about the saved file. |
Definition at line 195 of file jpeg_writer.cpp.
References CLAW_EXCEPTION, CLAW_PRECOND, create_compress_info(), claw::graphic::jpeg::error_manager::error_string, claw::graphic::jpeg::error_manager::pub, save_image(), set_options(), and claw::graphic::jpeg::error_manager::setjmp_buffer.
{ CLAW_PRECOND( !!f ); destination_manager outfile(f); jpeg_compress_struct cinfo; error_manager jerr; cinfo.err = jpeg_std_error(&jerr.pub); jerr.pub.error_exit = jpeg__error_manager__error_exit; if ( setjmp(jerr.setjmp_buffer) ) throw CLAW_EXCEPTION(jerr.error_string); create_compress_info( cinfo, outfile ); try { set_options( cinfo, opt ); save_image( cinfo ); jpeg_destroy_compress(&cinfo); } catch(...) { jpeg_abort_compress(&cinfo); jpeg_destroy_compress(&cinfo); throw; } } // jpeg::writer::save()
void claw::graphic::jpeg::writer::save_image | ( | jpeg_compress_struct & | cinfo | ) | const [private] |
Save the image in the configured stream.
cinfo | The structure to initialize. |
Definition at line 256 of file jpeg_writer.cpp.
References CLAW_EXCEPTION, copy_pixel_line(), claw::graphic::jpeg::error_manager::error_string, m_image, claw::graphic::jpeg::error_manager::pub, s_rgb_pixel_size, claw::graphic::jpeg::error_manager::setjmp_buffer, and claw::graphic::image::width().
Referenced by save().
{ JSAMPLE* data = new JSAMPLE[ m_image.width() * s_rgb_pixel_size ]; error_manager jerr; jpeg_error_mgr* jerr_saved = cinfo.err; cinfo.err = jpeg_std_error(&jerr.pub); jerr.pub.error_exit = jpeg__error_manager__error_exit; if ( setjmp(jerr.setjmp_buffer) ) { delete[] data; jpeg_abort_compress(&cinfo); throw CLAW_EXCEPTION(jerr.error_string); } jpeg_start_compress( &cinfo, TRUE ); while (cinfo.next_scanline < cinfo.image_height) { copy_pixel_line( data, cinfo.next_scanline ); jpeg_write_scanlines( &cinfo, &data, 1 ); } delete[] data; jpeg_finish_compress(&cinfo); cinfo.err = jerr_saved; } // jpeg::writer::load()
void claw::graphic::jpeg::writer::set_options | ( | jpeg_compress_struct & | cinfo, | |
const options & | opt | |||
) | const [private] |
Set the parameters of the JPEG saving structures.
cinfo | JPEG file description. | |
opt | Options about the saved file. |
Definition at line 232 of file jpeg_writer.cpp.
References claw::graphic::jpeg::writer::options::progressive, and claw::graphic::jpeg::writer::options::quality.
Referenced by save().
{ cinfo.image_width = m_image.width(); /* image width, in pixels */ cinfo.image_height = m_image.height(); /* image height, in pixels */ cinfo.input_components = s_rgb_pixel_size; /* # of components per pixel */ cinfo.in_color_space = JCS_RGB; /* colorspace of input image */ jpeg_set_defaults(&cinfo); if (opt.quality > 100) jpeg_set_quality(&cinfo, 100, TRUE); else jpeg_set_quality(&cinfo, opt.quality, TRUE); if (opt.progressive) jpeg_simple_progression(&cinfo); } // jpeg::writer::set_options()
const image& claw::graphic::jpeg::writer::m_image [private] |
The image from which we thake the data to save.
Definition at line 239 of file jpeg.hpp.
Referenced by save_image().
const unsigned int claw::graphic::jpeg::writer::s_rgb_pixel_size = 3 [static, private] |
Size, in bytes, of a red/green/blue pixel in a jpeg file.
Definition at line 243 of file jpeg.hpp.
Referenced by save_image().