/*========================================================================= Program: gdcm Module: $RCSfile: gdcmJpeg12.cxx,v $ Language: C++ Date: $Date: 2004/10/10 16:44:00 $ Version: $Revision: 1.20 $ Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de l'Image). All rights reserved. See Doc/License.txt or http://www.creatis.insa-lyon.fr/Public/Gdcm/License.html for details. This software is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the above copyright notices for more information. =========================================================================*/ #include "gdcmFile.h" /* * is used for the optional error recovery mechanism shown in * the second part of the example. */ /* * Include file for users of JPEG library. * You will need to have included system headers that define at least * the typedefs FILE and size_t before you can include jpeglib.h. * (stdio.h is sufficient on ANSI-conforming systems.) * You may also wish to include "jerror.h". */ extern "C" { #include "src/jpeg/libijg12/jconfig.h" #include "src/jpeg/libijg12/jpeglib.h" #include } /******************** JPEG COMPRESSION SAMPLE INTERFACE *******************/ // // TODO // bool gdcm_write_JPEG_file12 (FILE* fp, void* im_buff, int image_width, int image_heigh, int quality) { (void)fp; (void)im_buff; (void)image_width; (void)image_heigh; (void)quality; return true; //??? } /******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/ /* This half of the example shows how to read data from the JPEG decompressor. * It's a bit more refined than the above, in that we show: * (a) how to modify the JPEG library's standard error-reporting behavior; * (b) how to allocate workspace using the library's memory manager. * * Just to make this example a little different from the first one, we'll * assume that we do not intend to put the whole image into an in-memory * buffer, but to send it line-by-line someplace else. We need a one- * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG * memory manager allocate it for us. This approach is actually quite useful * because we don't need to remember to deallocate the buffer separately: it * will go away automatically when the JPEG object is cleaned up. */ /* * ERROR HANDLING: * * The JPEG library's standard error handler (jerror.c) is divided into * several "methods" which you can override individually. This lets you * adjust the behavior without duplicating a lot of code, which you might * have to update with each future release. * * Our example here shows how to override the "error_exit" method so that * control is returned to the library's caller when a fatal error occurs, * rather than calling exit() as the standard error_exit method does. * * We use C's setjmp/longjmp facility to return control. This means that the * routine which calls the JPEG library must first execute a setjmp() call to * establish the return point. We want the replacement error_exit to do a * longjmp(). But we need to make the setjmp buffer accessible to the * error_exit routine. To do this, we make a private extension of the * standard JPEG error handler object. (If we were using C++, we'd say we * were making a subclass of the regular error handler.) * * Here's the extended error handler struct: */ //----------------------------------------------------------------------------- struct my_error_mgr { struct jpeg_error_mgr pub; /* "public" fields */ jmp_buf setjmp_buffer; /* for return to caller */ }; //----------------------------------------------------------------------------- typedef struct my_error_mgr * my_error_ptr; /* * Here's the routine that will replace the standard error_exit method: */ METHODDEF(void) my_error_exit (j_common_ptr cinfo) { /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */ my_error_ptr myerr = (my_error_ptr) cinfo->err; /* Always display the message. */ /* We could postpone this until after returning, if we chose. */ (*cinfo->err->output_message) (cinfo); /* Return control to the setjmp point */ longjmp(myerr->setjmp_buffer, 1); } //----------------------------------------------------------------------------- /* * Sample routine for JPEG decompression. We assume that the source file name * is passed in. We want to return 1 on success, 0 on error. */ /** * \ingroup gdcmFile * \brief routine for JPEG decompression * @param fp pointer to an already open file descriptor * 12 significant bits per pixel * @param image_buffer to receive uncompressed pixels * @return 1 on success, 0 on error */ bool gdcm_read_JPEG_file12 ( FILE* fp,void* image_buffer ) { char *pimage; /* This struct contains the JPEG decompression parameters and pointers to * working space (which is allocated as needed by the JPEG library). */ struct jpeg_decompress_struct cinfo; /* -------------- inside, we found : * JDIMENSION image_width; // input image width * JDIMENSION image_height; // input image height * int input_components; // nb of color components in input image * J_COLOR_SPACE in_color_space;// colorspace of input image * double input_gamma; // image gamma of input image * -------------- */ /* We use our private extension JPEG error handler. * Note that this struct must live as long as the main JPEG parameter * struct, to avoid dangling-pointer problems. */ struct my_error_mgr jerr; /* More stuff */ JSAMPARRAY buffer;/* Output row buffer */ // rappel : // ------ // typedef unsigned char JSAMPLE; // typedef JSAMPLE FAR *JSAMPROW;/* ptr to one image row of pixel samples. */ // typedef JSAMPROW *JSAMPARRAY;/* ptr to some rows (a 2-D sample array) */ // typedef JSAMPARRAY *JSAMPIMAGE;/* a 3-D sample array: top index is color */ int row_stride;/* physical row width in output buffer */ #ifdef GDCM_JPG_DEBUG printf("entree dans gdcmFile::gdcm_read_JPEG_file12, depuis gdcmJpeg\n"); #endif //GDCM_JPG_DEBUG /* In this example we want to open the input file before doing anything else, * so that the setjmp() error recovery below can assume the file is open. * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that * requires it in order to read binary files. */ /* Step 1: allocate and initialize JPEG decompression object */ #ifdef GDCM_JPG_DEBUG printf("Entree Step 1\n"); #endif //GDCM_JPG_DEBUG /* We set up the normal JPEG error routines, then override error_exit. */ cinfo.err = jpeg_std_error(&jerr.pub); jerr.pub.error_exit = my_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_decompress(&cinfo); return(false); } /* Now we can initialize the JPEG decompression object. */ jpeg_create_decompress(&cinfo); /* Step 2: specify data source (eg, a file) */ #ifdef GDCM_JPG_DEBUG printf("Entree Step 2\n"); #endif //GDCM_JPG_DEBUG jpeg_stdio_src(&cinfo, fp); /* Step 3: read file parameters with jpeg_read_header() */ #ifdef GDCM_JPG_DEBUG printf("Entree Step 3\n"); #endif //GDCM_JPG_DEBUG (void) jpeg_read_header(&cinfo, TRUE); /* We can ignore the return value from jpeg_read_header since * (a) suspension is not possible with the stdio data source, and * (b) we passed TRUE to reject a tables-only JPEG file as an error. * See libjpeg.doc for more info. */ #ifdef GDCM_JPG_DEBUG printf("--------------Header contents :----------------\n"); printf("image_width %d image_height %d\n", cinfo.image_width , cinfo.image_height); printf("bits of precision in image data %d \n", cinfo.output_components); printf("nb of color components returned %d \n", cinfo.data_precision); #endif //GDCM_JPG_DEBUG /* * JDIMENSION image_width; // input image width * JDIMENSION image_height; // input image height * int output_components; // # of color components returned * J_COLOR_SPACE in_color_space; // colorspace of input image * double input_gamma; // image gamma of input image * int data_precision; // bits of precision in image data */ /* Step 4: set parameters for decompression */ #ifdef GDCM_JPG_DEBUG printf("Entree Step 4\n"); #endif //GDCM_JPG_DEBUG /* In this example, we don't need to change any of the defaults set by * jpeg_read_header(), so we do nothing here. */ /* Step 5: Start decompressor */ #ifdef GDCM_JPG_DEBUG printf("Entree Step 5\n"); #endif //GDCM_JPG_DEBUG (void) jpeg_start_decompress(&cinfo); /* We can ignore the return value since suspension is not possible * with the stdio data source. */ /* We may need to do some setup of our own at this point before reading * the data. After jpeg_start_decompress() we have the correct scaled * output image dimensions available, as well as the output colormap * if we asked for color quantization. * In this example, we need to make an output work buffer of the right size. */ /* JSAMPLEs per row in output buffer */ row_stride = cinfo.output_width * cinfo.output_components; #ifdef GDCM_JPG_DEBUG printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n", cinfo.output_width, cinfo.output_components,row_stride); #endif //GDCM_JPG_DEBUG /* Make a one-row-high sample array that will go away when done with image */ buffer = (*cinfo.mem->alloc_sarray) ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1); /* Step 6: while (scan lines remain to be read) */ #ifdef GDCM_JPG_DEBUG printf("Entree Step 6\n"); #endif //GDCM_JPG_DEBUG /* jpeg_read_scanlines(...); */ /* Here we use the library's state variable cinfo.output_scanline as the * loop counter, so that we don't have to keep track ourselves. */ #ifdef GDCM_JPG_DEBUG printf ("cinfo.output_height %d cinfo.output_width %d\n", cinfo.output_height,cinfo.output_width); #endif //GDCM_JPG_DEBUG pimage=(char *)image_buffer; while (cinfo.output_scanline < cinfo.output_height) { /* jpeg_read_scanlines expects an array of pointers to scanlines. * Here the array is only one element long, but you could ask for * more than one scanline at a time if that's more convenient. */ (void) jpeg_read_scanlines(&cinfo, buffer, 1); if ( BITS_IN_JSAMPLE == 8) { memcpy( pimage, buffer[0],row_stride); pimage+=row_stride; } else { memcpy( pimage, buffer[0],row_stride*2 ); // FIXME : *2 car 16 bits?!? pimage+=row_stride*2; // FIXME : *2 car 16 bits?!? } } /* Step 7: Finish decompression */ #ifdef GDCM_JPG_DEBUG printf("Entree Step 7\n"); #endif //GDCM_JPG_DEBUG (void) jpeg_finish_decompress(&cinfo); /* We can ignore the return value since suspension is not possible * with the stdio data source. */ /* Step 8: Release JPEG decompression object */ #ifdef GDCM_JPG_DEBUG printf("Entree Step 8\n"); #endif //GDCM_JPG_DEBUG /* This is an important step since it will release a good deal of memory. */ jpeg_destroy_decompress(&cinfo); /* After finish_decompress, we can close the input file. * Here we postpone it until after no more JPEG errors are possible, * so as to simplify the setjmp error logic above. (Actually, I don't * think that jpeg_destroy can do an error exit, but why assume anything...) */ /* At this point you may want to check to see whether any corrupt-data * warnings occurred (test whether jerr.pub.num_warnings is nonzero). */ /* And we're done! */ return true; } /* * SOME FINE POINTS: * * In the above code, we ignored the return value of jpeg_read_scanlines, * which is the number of scanlines actually read. We could get away with * this because we asked for only one line at a time and we weren't using * a suspending data source. See libjpeg.doc for more info. * * We cheated a bit by calling alloc_sarray() after jpeg_start_decompress(); * we should have done it beforehand to ensure that the space would be * counted against the JPEG max_memory setting. In some systems the above * code would risk an out-of-memory error. However, in general we don't * know the output image dimensions before jpeg_start_decompress(), unless we * call jpeg_calc_output_dimensions(). See libjpeg.doc for more about this. * * Scanlines are returned in the same order as they appear in the JPEG file, * which is standardly top-to-bottom. If you must emit data bottom-to-top, * you can use one of the virtual arrays provided by the JPEG memory manager * to invert the data. See wrbmp.c for an example. * * As with compression, some operating modes may require temporary files. * On some systems you may need to set up a signal handler to ensure that * temporary files are deleted if the program is interrupted. See libjpeg.doc. */ //-----------------------------------------------------------------------------