diff options
Diffstat (limited to 'ml/dlib/dlib/image_saver/save_jpeg.cpp')
| -rw-r--r-- | ml/dlib/dlib/image_saver/save_jpeg.cpp | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/ml/dlib/dlib/image_saver/save_jpeg.cpp b/ml/dlib/dlib/image_saver/save_jpeg.cpp new file mode 100644 index 000000000..ef637fa7a --- /dev/null +++ b/ml/dlib/dlib/image_saver/save_jpeg.cpp @@ -0,0 +1,175 @@ +// Copyright (C) 2014 Davis E. King (davis@dlib.net), Nils Labugt +// License: Boost Software License See LICENSE.txt for the full license. +#ifndef DLIB_JPEG_SAVER_CPp_ +#define DLIB_JPEG_SAVER_CPp_ + +// only do anything with this file if DLIB_JPEG_SUPPORT is defined +#ifdef DLIB_JPEG_SUPPORT + +#include "../array2d.h" +#include "../pixel.h" +#include "save_jpeg.h" +#include <stdio.h> +#include <sstream> +#include <setjmp.h> +#include "image_saver.h" + +#ifdef DLIB_JPEG_STATIC +# include "../external/libjpeg/jpeglib.h" +#else +# include <jpeglib.h> +#endif + +namespace dlib +{ + +// ---------------------------------------------------------------------------------------- + + struct jpeg_saver_error_mgr + { + jpeg_error_mgr pub; /* "public" fields */ + jmp_buf setjmp_buffer; /* for return to caller */ + }; + + void jpeg_saver_error_exit (j_common_ptr cinfo) + { + /* cinfo->err really points to a jpeg_saver_error_mgr struct, so coerce pointer */ + jpeg_saver_error_mgr* myerr = (jpeg_saver_error_mgr*) cinfo->err; + + /* Return control to the setjmp point */ + longjmp(myerr->setjmp_buffer, 1); + } + +// ---------------------------------------------------------------------------------------- + + void save_jpeg ( + const array2d<rgb_pixel>& img, + const std::string& filename, + int quality + ) + { + // make sure requires clause is not broken + DLIB_CASSERT(img.size() != 0, + "\t save_jpeg()" + << "\n\t You can't save an empty image as a JPEG." + ); + DLIB_CASSERT(0 <= quality && quality <= 100, + "\t save_jpeg()" + << "\n\t Invalid quality value." + << "\n\t quality: " << quality + ); + + FILE* outfile = fopen(filename.c_str(), "wb"); + if (!outfile) + throw image_save_error("Can't open file " + filename + " for writing."); + + jpeg_compress_struct cinfo; + + jpeg_saver_error_mgr jerr; + cinfo.err = jpeg_std_error(&jerr.pub); + jerr.pub.error_exit = jpeg_saver_error_exit; + /* Establish the setjmp return context for my_error_exit to use. */ + if (setjmp(jerr.setjmp_buffer)) + { + /* If we get here, the JPEG code has signaled an error. + * We need to clean up the JPEG object, close the input file, and return. + */ + jpeg_destroy_compress(&cinfo); + fclose(outfile); + throw image_save_error("save_jpeg: error while writing " + filename); + } + + jpeg_create_compress(&cinfo); + jpeg_stdio_dest(&cinfo, outfile); + + cinfo.image_width = img.nc(); + cinfo.image_height = img.nr(); + cinfo.input_components = 3; + cinfo.in_color_space = JCS_RGB; + jpeg_set_defaults(&cinfo); + jpeg_set_quality (&cinfo, quality, TRUE); + jpeg_start_compress(&cinfo, TRUE); + + // now write out the rows one at a time + while (cinfo.next_scanline < cinfo.image_height) { + JSAMPROW row_pointer = (JSAMPROW) &img[cinfo.next_scanline][0]; + jpeg_write_scanlines(&cinfo, &row_pointer, 1); + } + + jpeg_finish_compress(&cinfo); + jpeg_destroy_compress(&cinfo); + fclose( outfile ); + } + +// ---------------------------------------------------------------------------------------- + + void save_jpeg ( + const array2d<unsigned char>& img, + const std::string& filename, + int quality + ) + { + // make sure requires clause is not broken + DLIB_CASSERT(img.size() != 0, + "\t save_jpeg()" + << "\n\t You can't save an empty image as a JPEG." + ); + DLIB_CASSERT(0 <= quality && quality <= 100, + "\t save_jpeg()" + << "\n\t Invalid quality value." + << "\n\t quality: " << quality + ); + + + FILE* outfile = fopen(filename.c_str(), "wb"); + if (!outfile) + throw image_save_error("Can't open file " + filename + " for writing."); + + jpeg_compress_struct cinfo; + + jpeg_saver_error_mgr jerr; + cinfo.err = jpeg_std_error(&jerr.pub); + jerr.pub.error_exit = jpeg_saver_error_exit; + /* Establish the setjmp return context for my_error_exit to use. */ + if (setjmp(jerr.setjmp_buffer)) + { + /* If we get here, the JPEG code has signaled an error. + * We need to clean up the JPEG object, close the input file, and return. + */ + jpeg_destroy_compress(&cinfo); + fclose(outfile); + throw image_save_error("save_jpeg: error while writing " + filename); + } + + jpeg_create_compress(&cinfo); + jpeg_stdio_dest(&cinfo, outfile); + + cinfo.image_width = img.nc(); + cinfo.image_height = img.nr(); + cinfo.input_components = 1; + cinfo.in_color_space = JCS_GRAYSCALE; + jpeg_set_defaults(&cinfo); + jpeg_set_quality (&cinfo, quality, TRUE); + jpeg_start_compress(&cinfo, TRUE); + + // now write out the rows one at a time + while (cinfo.next_scanline < cinfo.image_height) { + JSAMPROW row_pointer = (JSAMPROW) &img[cinfo.next_scanline][0]; + jpeg_write_scanlines(&cinfo, &row_pointer, 1); + } + + jpeg_finish_compress(&cinfo); + jpeg_destroy_compress(&cinfo); + fclose( outfile ); + } + +// ---------------------------------------------------------------------------------------- + +} + +#endif // DLIB_JPEG_SUPPORT + +#endif // DLIB_JPEG_SAVER_CPp_ + + + |