X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=blobdiff_plain;f=src%2FgdcmJpeg.cxx;h=d7579773fdd75064f7a3f18d0de57a48b4cafd6b;hb=9ca4fd0ccbfea12ed7760856de3a8faf41625869;hp=123f68e1c1083f603075cfb0cee205b74ea7c775;hpb=b1520ca5b7b3665aa40c14b63169bfab92eece55;p=gdcm.git diff --git a/src/gdcmJpeg.cxx b/src/gdcmJpeg.cxx index 123f68e1..d7579773 100644 --- a/src/gdcmJpeg.cxx +++ b/src/gdcmJpeg.cxx @@ -1,12 +1,22 @@ -// gdcmJpeg.cxx -//----------------------------------------------------------------------------- -#include +/*========================================================================= + + Program: gdcm + Module: $RCSfile: gdcmJpeg.cxx,v $ + Language: C++ + Date: $Date: 2004/12/12 17:21:08 $ + Version: $Revision: 1.29 $ + + 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" -#define BITS_IN_JSAMPLE 8 - -#define GDCM_jpr_DEBUG 0 - /* DICOM provides a mechanism for supporting the use of JPEG Image Compression through the Encapsulated Format (see PS 3.3 of the DICOM Standard). @@ -74,11 +84,209 @@ of the uncompressed pixel data from which the compressed data is derived * You may also wish to include "jerror.h". */ -extern "C" { -#include "jpeglib.h" #include +#include +#include "jdatasrc.cxx" +#include "jdatadst.cxx" + +namespace gdcm +{ +/******************** JPEG COMPRESSION SAMPLE INTERFACE *******************/ + +/* This half of the example shows how to feed data into the JPEG compressor. + * We present a minimal version that does not worry about refinements such + * as error recovery (the JPEG code will just exit() if it gets an error). + */ + +/* + * IMAGE DATA FORMATS: + * + * The standard input image format is a rectangular array of pixels, with + * each pixel having the same number of "component" values (color channels). + * Each pixel row is an array of JSAMPLEs (which typically are unsigned chars). + * If you are working with color data, then the color values for each pixel + * must be adjacent in the row; for example, R,G,B,R,G,B,R,G,B,... for 24-bit + * RGB color. + * + * For this example, we'll assume that this data structure matches the way + * our application has stored the image in memory, so we can just pass a + * pointer to our image buffer. In particular, let's say that the image is + * RGB color and is described by: + */ + + +//extern JSAMPLE * image_buffer; /* Points to large array of R,G,B-order data */ +//extern int image_height; /* Number of rows in image */ +//extern int image_width; /* Number of columns in image */ + + + +/* + * Sample routine for JPEG compression. We assume that the target file name + * and a compression quality factor are passed in. + */ + + /** + * \ingroup File + * \brief routine for JPEG decompression + * @param fp pointer to an already open file descriptor + * 8 significant bits per pixel + * @param im_buf Points to array (of R,G,B-order) data to compress + * @param quality compression quality + * @param image_height Number of rows in image + * @param image_width Number of columns in image + * @return 1 on success, 0 on error + */ + +bool gdcm_write_JPEG_file (std::ofstream* fp, void* im_buf, + int image_width, int image_height, int quality) +{ + + JSAMPLE* image_buffer = (JSAMPLE*) im_buf; + + /* This struct contains the JPEG compression parameters and pointers to + * working space (which is allocated as needed by the JPEG library). + * It is possible to have several such structures, representing multiple + * compression/decompression processes, in existence at once. We refer + * to any one struct (and its associated working data) as a "JPEG object". + */ + struct jpeg_compress_struct cinfo; + /* This struct represents a JPEG error handler. It is declared separately + * because applications often want to supply a specialized error handler + * (see the second half of this file for an example). But here we just + * take the easy way out and use the standard error handler, which will + * print a message on stderr and call exit() if compression fails. + * Note that this struct must live as long as the main JPEG parameter + * struct, to avoid dangling-pointer problems. + */ + struct jpeg_error_mgr jerr; + /* More stuff */ + //FILE* outfile; /* target FILE* / + JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */ + int row_stride; /* physical row width in image buffer */ + + /* Step 1: allocate and initialize JPEG compression object */ + + /* We have to set up the error handler first, in case the initialization + * step fails. (Unlikely, but it could happen if you are out of memory.) + * This routine fills in the contents of struct jerr, and returns jerr's + * address which we place into the link field in cinfo. + */ + cinfo.err = jpeg_std_error(&jerr); + /* Now we can initialize the JPEG compression object. */ + jpeg_create_compress(&cinfo); + + /* Step 2: specify data destination (eg, a file) */ + /* Note: steps 2 and 3 can be done in either order. */ + + /* Here we use the library-supplied code to send compressed data to a + * stdio stream. You can also write your own code to do something else. + * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that + * requires it in order to write binary files. + */ + // if ((outfile = fopen(filename, "wb")) == NULL) { + // fprintf(stderr, "can't open %s\n", filename); + // exit(1); + // + // } + jpeg_stdio_dest(&cinfo, fp); + + /* Step 3: set parameters for compression */ + + /* First we supply a description of the input image. + * Four fields of the cinfo struct must be filled in: + */ + cinfo.image_width = image_width;/* image width and height, in pixels */ + cinfo.image_height = image_height; + cinfo.input_components = 3; /* # of color components per pixel */ + cinfo.in_color_space = JCS_RGB; /* colorspace of input image */ + /* Now use the library's routine to set default compression parameters. + * (You must set at least cinfo.in_color_space before calling this, + * since the defaults depend on the source color space.) + */ + jpeg_set_defaults(&cinfo); + /* Now you can set any non-default parameters you wish to. + * Here we just illustrate the use of quality (quantization table) scaling: + */ + jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */); + + /* Step 4: Start compressor */ + + /* TRUE ensures that we will write a complete interchange-JPEG file. + * Pass TRUE unless you are very sure of what you're doing. + */ + jpeg_start_compress(&cinfo, TRUE); + + /* Step 5: while (scan lines remain to be written) */ + /* jpeg_write_scanlines(...); */ + + /* Here we use the library's state variable cinfo.next_scanline as the + * loop counter, so that we don't have to keep track ourselves. + * To keep things simple, we pass one scanline per call; you can pass + * more if you wish, though. + */ + row_stride = image_width * 3;/* JSAMPLEs per row in image_buffer */ + + while (cinfo.next_scanline < cinfo.image_height) { + /* jpeg_write_scanlines expects an array of pointers to scanlines. + * Here the array is only one element long, but you could pass + * more than one scanline at a time if that's more convenient. + */ + row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride]; + + (void) jpeg_write_scanlines(&cinfo, row_pointer, 1); + } + + /* Step 6: Finish compression */ + + jpeg_finish_compress(&cinfo); + + /* After finish_compress, we can close the output file. */ + + // fclose(fp); --> the caller will close (multiframe treatement) + + /* Step 7: release JPEG compression object */ + + /* This is an important step since it will release a good deal of memory. */ + jpeg_destroy_compress(&cinfo); + + /* And we're done! */ + + return true; //??? } + + +/* + * SOME FINE POINTS: + * + * In the above loop, we ignored the return value of jpeg_write_scanlines, + * which is the number of scanlines actually written. We could get away + * with this because we were only relying on the value of cinfo.next_scanline, + * which will be incremented correctly. If you maintain additional loop + * variables then you should be careful to increment them properly. + * Actually, for output to a stdio stream you needn't worry, because + * then jpeg_write_scanlines will write all the lines passed (or else exit + * with a fatal error). Partial writes can only occur if you use a data + * destination module that can demand suspension of the compressor. + * (If you don't know what that's for, you don't need it.) + * + * If the compressor requires full-image buffers (for entropy-coding + * optimization or a multi-scan JPEG file), it will create temporary + * files for anything that doesn't fit within the maximum-memory setting. + * (Note that temp files are NOT needed if you use the default parameters.) + * 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. + * + * Scanlines MUST be supplied in top-to-bottom order if you want your JPEG + * files to be compatible with everyone else's. If you cannot readily read + * your data in that order, you'll need an intermediate array to hold the + * image. See rdtarga.c or rdbmp.c for examples of handling bottom-to-top + * source data using the JPEG code's internal virtual-array mechanisms. + */ + + + /******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/ /* This half of the example shows how to read data from the JPEG decompressor. @@ -120,12 +328,12 @@ extern "C" { //----------------------------------------------------------------------------- struct my_error_mgr { - struct jpeg_error_mgr pub; /* "public" fields */ - jmp_buf setjmp_buffer; /* for return to caller */ + struct jpeg_error_mgr pub; /* "public" fields */ + jmp_buf setjmp_buffer; /* for return to caller */ }; //----------------------------------------------------------------------------- -typedef struct my_error_mgr * my_error_ptr; +typedef struct my_error_mgr* my_error_ptr; /* * Here's the routine that will replace the standard error_exit method: @@ -149,7 +357,6 @@ METHODDEF(void) my_error_exit (j_common_ptr cinfo) { */ /** - * \ingroup gdcmFile * \brief routine for JPEG decompression * @param fp pointer to an already open file descriptor * 8 significant bits per pixel @@ -157,8 +364,9 @@ METHODDEF(void) my_error_exit (j_common_ptr cinfo) { * @return 1 on success, 0 on error */ -bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { - char *pimage; +bool gdcm_read_JPEG_file ( std::ifstream* 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). @@ -166,11 +374,11 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { 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 + * 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. @@ -180,20 +388,20 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { struct my_error_mgr jerr; /* More stuff */ - JSAMPARRAY buffer; /* Output row buffer */ + 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 */ + // 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 */ + int row_stride;/* physical row width in output buffer */ -#ifdef GDCM_jpr_DEBUG - printf("entree dans gdcmFile::gdcm_read_JPEG_file12, depuis gdcmJpeg\n"); -#endif //GDCM_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG + printf("entree dans File::gdcm_read_JPEG_file (i.e. 8), 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. @@ -202,9 +410,9 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { */ /* Step 1: allocate and initialize JPEG decompression object */ -#ifdef GDCM_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf("Entree Step 1\n"); -#endif //GDCM_jpr_DEBUG +#endif //GDCM_JPG_DEBUG /* We set up the normal JPEG error routines, then override error_exit. */ @@ -212,7 +420,8 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { jerr.pub.error_exit = my_error_exit; /* Establish the setjmp return context for my_error_exit to use. */ - if (setjmp(jerr.setjmp_buffer)) { + 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. */ @@ -223,16 +432,16 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { jpeg_create_decompress(&cinfo); /* Step 2: specify data source (eg, a file) */ -#ifdef GDCM_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf("Entree Step 2\n"); -#endif //GDCM_jpr_DEBUG +#endif //GDCM_JPG_DEBUG jpeg_stdio_src(&cinfo, fp); /* Step 3: read file parameters with jpeg_read_header() */ -#ifdef GDCM_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf("Entree Step 3\n"); -#endif //GDCM_jpr_DEBUG +#endif //GDCM_JPG_DEBUG (void) jpeg_read_header(&cinfo, TRUE); @@ -242,7 +451,15 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { * See libjpeg.doc for more info. */ -#ifdef GDCM_jpr_DEBUG + // prevent the library from performing any color space conversion + if( cinfo.process == JPROC_LOSSLESS ) + { + cinfo.jpeg_color_space = JCS_UNKNOWN; + cinfo.out_color_space = JCS_UNKNOWN; + } + + +#ifdef GDCM_JPG_DEBUG printf("--------------Header contents :----------------\n"); printf("image_width %d image_height %d\n", cinfo.image_width , cinfo.image_height); @@ -250,30 +467,30 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { cinfo.output_components); printf("nb of color components returned %d \n", cinfo.data_precision); -#endif //GDCM_jpr_DEBUG +#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 + * 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_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf("Entree Step 4\n"); -#endif //GDCM_jpr_DEBUG +#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_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf("Entree Step 5\n"); -#endif //GDCM_jpr_DEBUG +#endif //GDCM_JPG_DEBUG (void) jpeg_start_decompress(&cinfo); /* We can ignore the return value since suspension is not possible @@ -288,59 +505,51 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { */ /* JSAMPLEs per row in output buffer */ - row_stride = cinfo.output_width * cinfo.output_components; + row_stride = cinfo.output_width * cinfo.output_components*2; -#ifdef GDCM_jpr_DEBUG +#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_jpr_DEBUG +#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_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf("Entree Step 6\n"); -#endif //GDCM_jpr_DEBUG +#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_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf ("cinfo.output_height %d cinfo.output_width %d\n", cinfo.output_height,cinfo.output_width); -#endif //GDCM_jpr_DEBUG +#endif //GDCM_JPG_DEBUG pimage=(char *)image_buffer; + int bufsize = cinfo.output_width * cinfo.output_components; + size_t rowsize = bufsize * sizeof(JSAMPLE); + 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. */ - - // l'image est deja allouée (et passée en param) - // on ecrit directement les pixels - // (on DEVRAIT pouvoir) - - //(void) jpeg_read_scanlines(&cinfo, pimage, 1); - - (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?!? - } - } - + + //printf( "scanlines: %d\n",cinfo.output_scanline); + (void) jpeg_read_scanlines(&cinfo, buffer, 1); + memcpy( pimage, *buffer,rowsize); + pimage+=rowsize; + } + /* Step 7: Finish decompression */ -#ifdef GDCM_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf("Entree Step 7\n"); -#endif //GDCM_jpr_DEBUG +#endif //GDCM_JPG_DEBUG (void) jpeg_finish_decompress(&cinfo); @@ -350,9 +559,9 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { /* Step 8: Release JPEG decompression object */ -#ifdef GDCM_jpr_DEBUG +#ifdef GDCM_JPG_DEBUG printf("Entree Step 8\n"); -#endif //GDCM_jpr_DEBUG +#endif //GDCM_JPG_DEBUG /* This is an important step since it will release a good deal of memory. */ @@ -370,9 +579,10 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { /* And we're done! */ - return(true); + return true; } + /* * SOME FINE POINTS: * @@ -398,4 +608,255 @@ bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { * temporary files are deleted if the program is interrupted. See libjpeg.doc. */ -//----------------------------------------------------------------------------- +//---------------------------------------------------------------------------- + + +/** + * \brief routine for JPEG decompression from a memory buffer. + * routine for JPEG decompression from a memory buffer. This routine + * only reads one JPEG image at a time, but returns information about + * how many bytes have been consumed from the \c input_buffer, and + * how many bytes have been written into the output \c image_buffer. + * + * @param input_buffer pointer to a memory buffer containing the jpeg + * compressed data. + * @param buflen length of the memory buffer. + * @param image_buffer pointer to the location where the decompressed + * image will be filled. + * @param howManyRead returns how many bytes have been consumed from the + * input_buffer. + * @param howManyWritten returns how many bytes have been written into + * the output image_buffer. + * @return 1 on success, 0 on error + */ + +bool gdcm_read_JPEG_memory ( const JOCTET* input_buffer, const size_t buflen, + void* image_buffer, + size_t *howManyRead, size_t *howManyWritten) +{ + char* pimage=(char *)image_buffer; + JOCTET* input = (JOCTET*) input_buffer; + + /* 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 File::gdcm_read_JPEG_file (i.e. 8), 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); + + *howManyRead += input - input_buffer; + *howManyWritten += pimage - (char *)image_buffer; + return 0; + } + + /* 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_memory_src(&cinfo, input, buflen); + + /* 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. + */ + + // prevent the library from performing any color space conversion + if( cinfo.process == JPROC_LOSSLESS ) + { + cinfo.jpeg_color_space = JCS_UNKNOWN; + cinfo.out_color_space = JCS_UNKNOWN; + } + +#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*2; + +#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 + + int bufsize = cinfo.output_width * cinfo.output_components; + size_t rowsize = bufsize * sizeof(JSAMPLE); + + 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. + */ + + //printf( "scanlines: %d\n",cinfo.output_scanline); + (void) jpeg_read_scanlines(&cinfo, buffer, 1); + memcpy( pimage, *buffer,rowsize); + pimage+=rowsize; + } + + /* Step 7: Finish decompression */ +#ifdef GDCM_JPG_DEBUG + printf("Entree Step 7\n"); +#endif //GDCM_JPG_DEBUG + + input = (JOCTET *)cinfo.src->next_input_byte; + + (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! */ + *howManyRead += input - input_buffer; + *howManyWritten += pimage - (char *)image_buffer; + + return true; +} + +} // end namespace gdcm