1 /*=========================================================================
4 Module: $RCSfile: gdcmJpeg.cxx,v $
6 Date: $Date: 2005/01/20 17:17:13 $
7 Version: $Revision: 1.34 $
9 Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
10 l'Image). All rights reserved. See Doc/License.txt or
11 http://www.creatis.insa-lyon.fr/Public/Gdcm/License.html for details.
13 This software is distributed WITHOUT ANY WARRANTY; without even
14 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
15 PURPOSE. See the above copyright notices for more information.
17 =========================================================================*/
18 #include "gdcmFileHelper.h"
21 DICOM provides a mechanism for supporting the use of JPEG Image Compression
22 through the Encapsulated Format (see PS 3.3 of the DICOM Standard).
23 Annex A defines a number of Transfer Syntaxes which reference
24 the JPEG Standard and provide a number of lossless (bit preserving)
25 and lossy compression schemes.
26 In order to facilitate interoperability of implementations conforming
27 to the DICOM Standard which elect to use one or more
28 of the Transfer Syntaxes for JPEG Image Compression, the following policy is specified:
30 Any implementation which conforms to the DICOM Standard and has elected
31 to support any one of the Transfer Syntaxes for lossless JPEG Image Compression,
32 shall support the following lossless compression:
33 The subset (first-order horizontal prediction [Selection Value 1) of JPEG Process 14
34 (DPCM, non-hierarchical with Huffman coding) (see Annex F of the DICOM Standard).
36 Any implementation which conforms to the DICOM Standard and has elected
37 to support any one of the Transfer Syntaxes for 8-bit lossy JPEG Image Compression,
38 shall support the JPEG Baseline Compression (coding Process 1).
40 Any implementation which conforms to the DICOM Standard and has elected
41 to support any one of the Transfer Syntaxes for 12-bit lossy JPEG Image Compression,
42 shall support the JPEG Compression Process 4.
44 Note: The DICOM conformance statement shall differentiate between implementations
45 that can simply receive JPEG encoded images and those that can receive and process
46 JPEG encoded images (see PS 3.2 of the DICOM Standard).
48 The use of the DICOM Encapsulated Format to support JPEG Compressed Pixel Data
49 implies that the Data Elements which are related to the Native Format Pixel Data encoding
50 (e.g. Bits Allocated, Bits Stored, High Bit, Pixel Representation, Rows, Columns, etc.)
51 shall contain values which are consistent with the characteristics
52 of the uncompressed pixel data from which the compressed Data Stream was derived.
53 The Pixel Data characteristics included in the JPEG Interchange Format
54 shall be used to decode the compressed data stream.
56 Run Length Encoding Compression
58 DICOM provides a mechanism for supporting the use of Run Length Encoding (RLE)
59 Compression which is a byte oriented lossless compression scheme through
60 the encapsulated Format (see PS 3.3 of this Standard).
61 Annex G of the DICOM Standard defines RLE Compression and its Transfer Syntax.
63 Note: The RLE Compression algorithm described in Annex G
64 of the DICOM Standard is the compression used in
65 the TIFF 6.0 specification known as the "PackBits" scheme.
67 The use of the DICOM Encapsulated Format to support RLE Compressed Pixel Data
68 implies that the Data Elements which are related to the Native Format Pixel Data encoding (
69 e.g. Bits Allocated, Bits Stored, High Bit, Pixel Representation, Rows, Columns, etc.)
70 shall contain values which are consistent with the characteristics
71 of the uncompressed pixel data from which the compressed data is derived
75 * <setjmp.h> is used for the optional error recovery mechanism shown in
76 * the second part of the example.
80 * Include file for users of JPEG library.
81 * You will need to have included system headers that define at least
82 * the typedefs FILE and size_t before you can include jpeglib.h.
83 * (stdio.h is sufficient on ANSI-conforming systems.)
84 * You may also wish to include "jerror.h".
89 #include "jdatasrc.cxx"
90 #include "jdatadst.cxx"
94 /******************** JPEG COMPRESSION SAMPLE INTERFACE *******************/
96 /* This half of the example shows how to feed data into the JPEG compressor.
97 * We present a minimal version that does not worry about refinements such
98 * as error recovery (the JPEG code will just exit() if it gets an error).
102 * IMAGE DATA FORMATS:
104 * The standard input image format is a rectangular array of pixels, with
105 * each pixel having the same number of "component" values (color channels).
106 * Each pixel row is an array of JSAMPLEs (which typically are unsigned chars).
107 * If you are working with color data, then the color values for each pixel
108 * must be adjacent in the row; for example, R,G,B,R,G,B,R,G,B,... for 24-bit
111 * For this example, we'll assume that this data structure matches the way
112 * our application has stored the image in memory, so we can just pass a
113 * pointer to our image buffer. In particular, let's say that the image is
114 * RGB color and is described by:
118 //extern JSAMPLE * image_buffer; /* Points to large array of R,G,B-order data */
119 //extern int image_height; /* Number of rows in image */
120 //extern int image_width; /* Number of columns in image */
125 * Sample routine for JPEG compression. We assume that the target file name
126 * and a compression quality factor are passed in.
130 * \brief routine for JPEG decompression
131 * @param fp pointer to an already open file descriptor
132 * 8 significant bits per pixel
133 * @param im_buf Points to array (of R,G,B-order) data to compress
134 * @param quality compression quality
135 * @param image_height Number of rows in image
136 * @param image_width Number of columns in image
137 * @return 1 on success, 0 on error
140 bool gdcm_write_JPEG_file (std::ofstream* fp, void* im_buf,
141 int image_width, int image_height, int quality)
144 JSAMPLE* image_buffer = (JSAMPLE*) im_buf;
146 /* This struct contains the JPEG compression parameters and pointers to
147 * working space (which is allocated as needed by the JPEG library).
148 * It is possible to have several such structures, representing multiple
149 * compression/decompression processes, in existence at once. We refer
150 * to any one struct (and its associated working data) as a "JPEG object".
152 struct jpeg_compress_struct cinfo;
153 /* This struct represents a JPEG error handler. It is declared separately
154 * because applications often want to supply a specialized error handler
155 * (see the second half of this file for an example). But here we just
156 * take the easy way out and use the standard error handler, which will
157 * print a message on stderr and call exit() if compression fails.
158 * Note that this struct must live as long as the main JPEG parameter
159 * struct, to avoid dangling-pointer problems.
161 struct jpeg_error_mgr jerr;
163 //FILE* outfile; /* target FILE* /
164 JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
165 int row_stride; /* physical row width in image buffer */
167 /* Step 1: allocate and initialize JPEG compression object */
169 /* We have to set up the error handler first, in case the initialization
170 * step fails. (Unlikely, but it could happen if you are out of memory.)
171 * This routine fills in the contents of struct jerr, and returns jerr's
172 * address which we place into the link field in cinfo.
174 cinfo.err = jpeg_std_error(&jerr);
175 /* Now we can initialize the JPEG compression object. */
176 jpeg_create_compress(&cinfo);
178 /* Step 2: specify data destination (eg, a file) */
179 /* Note: steps 2 and 3 can be done in either order. */
181 /* Here we use the library-supplied code to send compressed data to a
182 * stdio stream. You can also write your own code to do something else.
183 * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
184 * requires it in order to write binary files.
186 // if ((outfile = fopen(filename, "wb")) == NULL) {
187 // fprintf(stderr, "can't open %s\n", filename);
191 jpeg_stdio_dest(&cinfo, fp);
193 /* Step 3: set parameters for compression */
195 /* First we supply a description of the input image.
196 * Four fields of the cinfo struct must be filled in:
198 cinfo.image_width = image_width;/* image width and height, in pixels */
199 cinfo.image_height = image_height;
200 cinfo.input_components = 3; /* # of color components per pixel */
201 cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
202 /* Now use the library's routine to set default compression parameters.
203 * (You must set at least cinfo.in_color_space before calling this,
204 * since the defaults depend on the source color space.)
206 jpeg_set_defaults(&cinfo);
207 /* Now you can set any non-default parameters you wish to.
208 * Here we just illustrate the use of quality (quantization table) scaling:
210 jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
212 /* Step 4: Start compressor */
214 /* TRUE ensures that we will write a complete interchange-JPEG file.
215 * Pass TRUE unless you are very sure of what you're doing.
217 jpeg_start_compress(&cinfo, TRUE);
219 /* Step 5: while (scan lines remain to be written) */
220 /* jpeg_write_scanlines(...); */
222 /* Here we use the library's state variable cinfo.next_scanline as the
223 * loop counter, so that we don't have to keep track ourselves.
224 * To keep things simple, we pass one scanline per call; you can pass
225 * more if you wish, though.
227 row_stride = image_width * 3;/* JSAMPLEs per row in image_buffer */
229 while (cinfo.next_scanline < cinfo.image_height) {
230 /* jpeg_write_scanlines expects an array of pointers to scanlines.
231 * Here the array is only one element long, but you could pass
232 * more than one scanline at a time if that's more convenient.
234 row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride];
236 (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
239 /* Step 6: Finish compression */
241 jpeg_finish_compress(&cinfo);
243 /* After finish_compress, we can close the output file. */
245 // fclose(fp); --> the caller will close (multiframe treatement)
247 /* Step 7: release JPEG compression object */
249 /* This is an important step since it will release a good deal of memory. */
250 jpeg_destroy_compress(&cinfo);
252 /* And we're done! */
262 * In the above loop, we ignored the return value of jpeg_write_scanlines,
263 * which is the number of scanlines actually written. We could get away
264 * with this because we were only relying on the value of cinfo.next_scanline,
265 * which will be incremented correctly. If you maintain additional loop
266 * variables then you should be careful to increment them properly.
267 * Actually, for output to a stdio stream you needn't worry, because
268 * then jpeg_write_scanlines will write all the lines passed (or else exit
269 * with a fatal error). Partial writes can only occur if you use a data
270 * destination module that can demand suspension of the compressor.
271 * (If you don't know what that's for, you don't need it.)
273 * If the compressor requires full-image buffers (for entropy-coding
274 * optimization or a multi-scan JPEG file), it will create temporary
275 * files for anything that doesn't fit within the maximum-memory setting.
276 * (Note that temp files are NOT needed if you use the default parameters.)
277 * On some systems you may need to set up a signal handler to ensure that
278 * temporary files are deleted if the program is interrupted. See libjpeg.doc.
280 * Scanlines MUST be supplied in top-to-bottom order if you want your JPEG
281 * files to be compatible with everyone else's. If you cannot readily read
282 * your data in that order, you'll need an intermediate array to hold the
283 * image. See rdtarga.c or rdbmp.c for examples of handling bottom-to-top
284 * source data using the JPEG code's internal virtual-array mechanisms.
289 /******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/
291 /* This half of the example shows how to read data from the JPEG decompressor.
292 * It's a bit more refined than the above, in that we show:
293 * (a) how to modify the JPEG library's standard error-reporting behavior;
294 * (b) how to allocate workspace using the library's memory manager.
296 * Just to make this example a little different from the first one, we'll
297 * assume that we do not intend to put the whole image into an in-memory
298 * buffer, but to send it line-by-line someplace else. We need a one-
299 * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG
300 * memory manager allocate it for us. This approach is actually quite useful
301 * because we don't need to remember to deallocate the buffer separately: it
302 * will go away automatically when the JPEG object is cleaned up.
308 * The JPEG library's standard error handler (jerror.c) is divided into
309 * several "methods" which you can override individually. This lets you
310 * adjust the behavior without duplicating a lot of code, which you might
311 * have to update with each future release.
313 * Our example here shows how to override the "error_exit" method so that
314 * control is returned to the library's caller when a fatal error occurs,
315 * rather than calling exit() as the standard error_exit method does.
317 * We use C's setjmp/longjmp facility to return control. This means that the
318 * routine which calls the JPEG library must first execute a setjmp() call to
319 * establish the return point. We want the replacement error_exit to do a
320 * longjmp(). But we need to make the setjmp buffer accessible to the
321 * error_exit routine. To do this, we make a private extension of the
322 * standard JPEG error handler object. (If we were using C++, we'd say we
323 * were making a subclass of the regular error handler.)
325 * Here's the extended error handler struct:
328 //-----------------------------------------------------------------------------
329 struct my_error_mgr {
330 struct jpeg_error_mgr pub; /* "public" fields */
331 jmp_buf setjmp_buffer; /* for return to caller */
334 //-----------------------------------------------------------------------------
335 typedef struct my_error_mgr* my_error_ptr;
338 * Here's the routine that will replace the standard error_exit method:
340 METHODDEF(void) my_error_exit (j_common_ptr cinfo) {
341 /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
342 my_error_ptr myerr = (my_error_ptr) cinfo->err;
344 /* Always display the message. */
345 /* We could postpone this until after returning, if we chose. */
346 (*cinfo->err->output_message) (cinfo);
348 /* Return control to the setjmp point */
349 longjmp(myerr->setjmp_buffer, 1);
352 //-----------------------------------------------------------------------------
354 * Sample routine for JPEG decompression. We assume that the source file name
355 * is passed in. We want to return 1 on success, 0 on error.
359 * \brief routine for JPEG decompression
360 * @param fp pointer to an already open file descriptor
361 * 8 significant bits per pixel
362 * @param image_buffer to receive uncompressed pixels
363 * @return 1 on success, 0 on error
366 bool gdcm_read_JPEG_file ( std::ifstream* fp, void* image_buffer )
370 /* This struct contains the JPEG decompression parameters and pointers to
371 * working space (which is allocated as needed by the JPEG library).
373 struct jpeg_decompress_struct cinfo;
375 /* -------------- inside, we found :
376 * JDIMENSION image_width; // input image width
377 * JDIMENSION image_height; // input image height
378 * int input_components; // nb of color components in input image
379 * J_COLOR_SPACE in_color_space; // colorspace of input image
380 * double input_gamma; // image gamma of input image
383 /* We use our private extension JPEG error handler.
384 * Note that this struct must live as long as the main JPEG parameter
385 * struct, to avoid dangling-pointer problems.
387 struct my_error_mgr jerr;
390 JSAMPARRAY buffer;/* Output row buffer */
394 // typedef unsigned char JSAMPLE;
395 // typedef JSAMPLE FAR *JSAMPROW;/* ptr to one image row of pixel samples. */
396 // typedef JSAMPROW *JSAMPARRAY;/* ptr to some rows (a 2-D sample array) */
397 // typedef JSAMPARRAY *JSAMPIMAGE;/* a 3-D sample array: top index is color */
399 int row_stride;/* physical row width in output buffer */
401 #ifdef GDCM_JPG_DEBUG
402 printf("entree dans File::gdcm_read_JPEG_file (i.e. 8), depuis gdcmJpeg\n");
403 #endif //GDCM_JPG_DEBUG
405 /* In this example we want to open the input file before doing anything else,
406 * so that the setjmp() error recovery below can assume the file is open.
407 * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
408 * requires it in order to read binary files.
411 /* Step 1: allocate and initialize JPEG decompression object */
412 #ifdef GDCM_JPG_DEBUG
413 printf("Entree Step 1\n");
414 #endif //GDCM_JPG_DEBUG
416 /* We set up the normal JPEG error routines, then override error_exit. */
418 cinfo.err = jpeg_std_error(&jerr.pub);
419 jerr.pub.error_exit = my_error_exit;
421 /* Establish the setjmp return context for my_error_exit to use. */
422 if (setjmp(jerr.setjmp_buffer))
424 /* If we get here, the JPEG code has signaled an error.
425 * We need to clean up the JPEG object, close the input file, and return.
427 jpeg_destroy_decompress(&cinfo);
430 /* Now we can initialize the JPEG decompression object. */
431 jpeg_create_decompress(&cinfo);
433 /* Step 2: specify data source (eg, a file) */
434 #ifdef GDCM_JPG_DEBUG
435 printf("Entree Step 2\n");
436 #endif //GDCM_JPG_DEBUG
438 jpeg_stdio_src(&cinfo, fp);
440 /* Step 3: read file parameters with jpeg_read_header() */
441 #ifdef GDCM_JPG_DEBUG
442 printf("Entree Step 3\n");
443 #endif //GDCM_JPG_DEBUG
445 (void) jpeg_read_header(&cinfo, TRUE);
447 /* We can ignore the return value from jpeg_read_header since
448 * (a) suspension is not possible with the stdio data source, and
449 * (b) we passed TRUE to reject a tables-only JPEG file as an error.
450 * See libjpeg.doc for more info.
453 // prevent the library from performing any color space conversion
454 if( cinfo.process == JPROC_LOSSLESS )
456 cinfo.jpeg_color_space = JCS_UNKNOWN;
457 cinfo.out_color_space = JCS_UNKNOWN;
461 #ifdef GDCM_JPG_DEBUG
462 printf("--------------Header contents :----------------\n");
463 printf("image_width %d image_height %d\n",
464 cinfo.image_width , cinfo.image_height);
465 printf("bits of precision in image data %d \n",
466 cinfo.output_components);
467 printf("nb of color components returned %d \n",
468 cinfo.data_precision);
469 #endif //GDCM_JPG_DEBUG
473 * JDIMENSION image_width; // input image width
474 * JDIMENSION image_height; // input image height
475 * int output_components; // # of color components returned
476 * J_COLOR_SPACE in_color_space; // colorspace of input image
477 * double input_gamma; // image gamma of input image
478 * int data_precision; // bits of precision in image data
481 /* Step 4: set parameters for decompression */
482 #ifdef GDCM_JPG_DEBUG
483 printf("Entree Step 4\n");
484 #endif //GDCM_JPG_DEBUG
485 /* In this example, we don't need to change any of the defaults set by
486 * jpeg_read_header(), so we do nothing here.
489 /* Step 5: Start decompressor */
490 #ifdef GDCM_JPG_DEBUG
491 printf("Entree Step 5\n");
492 #endif //GDCM_JPG_DEBUG
494 (void) jpeg_start_decompress(&cinfo);
495 /* We can ignore the return value since suspension is not possible
496 * with the stdio data source.
499 /* We may need to do some setup of our own at this point before reading
500 * the data. After jpeg_start_decompress() we have the correct scaled
501 * output image dimensions available, as well as the output colormap
502 * if we asked for color quantization.
503 * In this example, we need to make an output work buffer of the right size.
506 /* JSAMPLEs per row in output buffer */
507 row_stride = cinfo.output_width * cinfo.output_components*2;
509 #ifdef GDCM_JPG_DEBUG
510 printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n",
511 cinfo.output_width, cinfo.output_components,row_stride);
512 #endif //GDCM_JPG_DEBUG
514 /* Make a one-row-high sample array that will go away when done with image */
515 buffer = (*cinfo.mem->alloc_sarray)
516 ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
518 /* Step 6: while (scan lines remain to be read) */
519 #ifdef GDCM_JPG_DEBUG
520 printf("Entree Step 6\n");
521 #endif //GDCM_JPG_DEBUG
522 /* jpeg_read_scanlines(...); */
524 /* Here we use the library's state variable cinfo.output_scanline as the
525 * loop counter, so that we don't have to keep track ourselves.
527 #ifdef GDCM_JPG_DEBUG
528 printf ("cinfo.output_height %d cinfo.output_width %d\n",
529 cinfo.output_height,cinfo.output_width);
530 #endif //GDCM_JPG_DEBUG
531 pimage=(char *)image_buffer;
533 int bufsize = cinfo.output_width * cinfo.output_components;
534 size_t rowsize = bufsize * sizeof(JSAMPLE);
536 while (cinfo.output_scanline < cinfo.output_height) {
537 /* jpeg_read_scanlines expects an array of pointers to scanlines.
538 * Here the array is only one element long, but you could ask for
539 * more than one scanline at a time if that's more convenient.
542 //printf( "scanlines: %d\n",cinfo.output_scanline);
543 (void) jpeg_read_scanlines(&cinfo, buffer, 1);
544 // The ijg has no notion of big endian, therefore always swap the jpeg stream
545 #if defined(GDCM_WORDS_BIGENDIAN) && (CMAKE_BITS_IN_JSAMPLE != 8)
546 uint16_t *buffer16 = (uint16_t*)*buffer;
547 uint16_t *pimage16 = (uint16_t*)pimage;
548 for(unsigned int i=0;i<rowsize/2;i++)
549 pimage16[i] = (buffer16[i] >> 8) | (buffer16[i] << 8 );
551 memcpy( pimage, *buffer,rowsize);
552 #endif //GDCM_WORDS_BIGENDIAN
556 /* Step 7: Finish decompression */
557 #ifdef GDCM_JPG_DEBUG
558 printf("Entree Step 7\n");
559 #endif //GDCM_JPG_DEBUG
561 (void) jpeg_finish_decompress(&cinfo);
563 /* We can ignore the return value since suspension is not possible
564 * with the stdio data source.
567 /* Step 8: Release JPEG decompression object */
569 #ifdef GDCM_JPG_DEBUG
570 printf("Entree Step 8\n");
571 #endif //GDCM_JPG_DEBUG
573 /* This is an important step since it will release a good deal of memory. */
575 jpeg_destroy_decompress(&cinfo);
577 /* After finish_decompress, we can close the input file.
578 * Here we postpone it until after no more JPEG errors are possible,
579 * so as to simplify the setjmp error logic above. (Actually, I don't
580 * think that jpeg_destroy can do an error exit, but why assume anything...)
583 /* At this point you may want to check to see whether any corrupt-data
584 * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
587 /* And we're done! */
596 * In the above code, we ignored the return value of jpeg_read_scanlines,
597 * which is the number of scanlines actually read. We could get away with
598 * this because we asked for only one line at a time and we weren't using
599 * a suspending data source. See libjpeg.doc for more info.
601 * We cheated a bit by calling alloc_sarray() after jpeg_start_decompress();
602 * we should have done it beforehand to ensure that the space would be
603 * counted against the JPEG max_memory setting. In some systems the above
604 * code would risk an out-of-memory error. However, in general we don't
605 * know the output image dimensions before jpeg_start_decompress(), unless we
606 * call jpeg_calc_output_dimensions(). See libjpeg.doc for more about this.
608 * Scanlines are returned in the same order as they appear in the JPEG file,
609 * which is standardly top-to-bottom. If you must emit data bottom-to-top,
610 * you can use one of the virtual arrays provided by the JPEG memory manager
611 * to invert the data. See wrbmp.c for an example.
613 * As with compression, some operating modes may require temporary files.
614 * On some systems you may need to set up a signal handler to ensure that
615 * temporary files are deleted if the program is interrupted. See libjpeg.doc.
618 //----------------------------------------------------------------------------
622 * \brief routine for JPEG decompression from a memory buffer.
623 * routine for JPEG decompression from a memory buffer. This routine
624 * only reads one JPEG image at a time, but returns information about
625 * how many bytes have been consumed from the \c input_buffer, and
626 * how many bytes have been written into the output \c image_buffer.
628 * @param input_buffer pointer to a memory buffer containing the jpeg
630 * @param buflen length of the memory buffer.
631 * @param image_buffer pointer to the location where the decompressed
632 * image will be filled.
633 * @param howManyRead returns how many bytes have been consumed from the
635 * @param howManyWritten returns how many bytes have been written into
636 * the output image_buffer.
637 * @return 1 on success, 0 on error
640 bool gdcm_read_JPEG_memory ( const JOCTET* input_buffer, const size_t buflen,
642 size_t *howManyRead, size_t *howManyWritten)
644 char* pimage=(char *)image_buffer;
645 JOCTET* input = (JOCTET*) input_buffer;
647 /* This struct contains the JPEG decompression parameters and pointers to
648 * working space (which is allocated as needed by the JPEG library).
650 struct jpeg_decompress_struct cinfo;
652 /* -------------- inside, we found :
653 * JDIMENSION image_width; // input image width
654 * JDIMENSION image_height; // input image height
655 * int input_components; // nb of color components in input image
656 * J_COLOR_SPACE in_color_space; // colorspace of input image
657 * double input_gamma; // image gamma of input image
660 /* We use our private extension JPEG error handler.
661 * Note that this struct must live as long as the main JPEG parameter
662 * struct, to avoid dangling-pointer problems.
664 struct my_error_mgr jerr;
667 JSAMPARRAY buffer;/* Output row buffer */
671 // typedef unsigned char JSAMPLE;
672 // typedef JSAMPLE FAR *JSAMPROW;/* ptr to one image row of pixel samples. */
673 // typedef JSAMPROW *JSAMPARRAY;/* ptr to some rows (a 2-D sample array) */
674 // typedef JSAMPARRAY *JSAMPIMAGE;/* a 3-D sample array: top index is color */
676 int row_stride;/* physical row width in output buffer */
678 #ifdef GDCM_JPG_DEBUG
679 printf("entree dans File::gdcm_read_JPEG_file (i.e. 8), depuis gdcmJpeg\n");
680 #endif //GDCM_JPG_DEBUG
682 /* In this example we want to open the input file before doing anything else,
683 * so that the setjmp() error recovery below can assume the file is open.
684 * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
685 * requires it in order to read binary files.
688 /* Step 1: allocate and initialize JPEG decompression object */
689 #ifdef GDCM_JPG_DEBUG
690 printf("Entree Step 1\n");
691 #endif //GDCM_JPG_DEBUG
693 /* We set up the normal JPEG error routines, then override error_exit. */
695 cinfo.err = jpeg_std_error(&jerr.pub);
696 jerr.pub.error_exit = my_error_exit;
698 /* Establish the setjmp return context for my_error_exit to use. */
699 if (setjmp(jerr.setjmp_buffer))
701 /* If we get here, the JPEG code has signaled an error.
702 * We need to clean up the JPEG object, close the input file, and return.
704 jpeg_destroy_decompress(&cinfo);
706 *howManyRead += input - input_buffer;
707 *howManyWritten += pimage - (char *)image_buffer;
711 /* Now we can initialize the JPEG decompression object. */
712 jpeg_create_decompress(&cinfo);
714 /* Step 2: specify data source (eg, a file) */
715 #ifdef GDCM_JPG_DEBUG
716 printf("Entree Step 2\n");
717 #endif //GDCM_JPG_DEBUG
719 jpeg_memory_src(&cinfo, input, buflen);
721 /* Step 3: read file parameters with jpeg_read_header() */
722 #ifdef GDCM_JPG_DEBUG
723 printf("Entree Step 3\n");
724 #endif //GDCM_JPG_DEBUG
726 (void) jpeg_read_header(&cinfo, TRUE);
728 /* We can ignore the return value from jpeg_read_header since
729 * (a) suspension is not possible with the stdio data source, and
730 * (b) we passed TRUE to reject a tables-only JPEG file as an error.
731 * See libjpeg.doc for more info.
734 // prevent the library from performing any color space conversion
735 if( cinfo.process == JPROC_LOSSLESS )
737 cinfo.jpeg_color_space = JCS_UNKNOWN;
738 cinfo.out_color_space = JCS_UNKNOWN;
741 #ifdef GDCM_JPG_DEBUG
742 printf("--------------Header contents :----------------\n");
743 printf("image_width %d image_height %d\n",
744 cinfo.image_width , cinfo.image_height);
745 printf("bits of precision in image data %d \n",
746 cinfo.output_components);
747 printf("nb of color components returned %d \n",
748 cinfo.data_precision);
749 #endif //GDCM_JPG_DEBUG
753 * JDIMENSION image_width; // input image width
754 * JDIMENSION image_height; // input image height
755 * int output_components; // # of color components returned
756 * J_COLOR_SPACE in_color_space; // colorspace of input image
757 * double input_gamma; // image gamma of input image
758 * int data_precision; // bits of precision in image data
761 /* Step 4: set parameters for decompression */
762 #ifdef GDCM_JPG_DEBUG
763 printf("Entree Step 4\n");
764 #endif //GDCM_JPG_DEBUG
765 /* In this example, we don't need to change any of the defaults set by
766 * jpeg_read_header(), so we do nothing here.
769 /* Step 5: Start decompressor */
770 #ifdef GDCM_JPG_DEBUG
771 printf("Entree Step 5\n");
772 #endif //GDCM_JPG_DEBUG
774 (void) jpeg_start_decompress(&cinfo);
775 /* We can ignore the return value since suspension is not possible
776 * with the stdio data source.
779 /* We may need to do some setup of our own at this point before reading
780 * the data. After jpeg_start_decompress() we have the correct scaled
781 * output image dimensions available, as well as the output colormap
782 * if we asked for color quantization.
783 * In this example, we need to make an output work buffer of the right size.
786 /* JSAMPLEs per row in output buffer */
787 row_stride = cinfo.output_width * cinfo.output_components*2;
789 #ifdef GDCM_JPG_DEBUG
790 printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n",
791 cinfo.output_width, cinfo.output_components,row_stride);
792 #endif //GDCM_JPG_DEBUG
794 /* Make a one-row-high sample array that will go away when done with image */
795 buffer = (*cinfo.mem->alloc_sarray)
796 ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
799 /* Step 6: while (scan lines remain to be read) */
800 #ifdef GDCM_JPG_DEBUG
801 printf("Entree Step 6\n");
802 #endif //GDCM_JPG_DEBUG
803 /* jpeg_read_scanlines(...); */
805 /* Here we use the library's state variable cinfo.output_scanline as the
806 * loop counter, so that we don't have to keep track ourselves.
808 #ifdef GDCM_JPG_DEBUG
809 printf ("cinfo.output_height %d cinfo.output_width %d\n",
810 cinfo.output_height,cinfo.output_width);
811 #endif //GDCM_JPG_DEBUG
813 int bufsize = cinfo.output_width * cinfo.output_components;
814 size_t rowsize = bufsize * sizeof(JSAMPLE);
816 while (cinfo.output_scanline < cinfo.output_height) {
817 /* jpeg_read_scanlines expects an array of pointers to scanlines.
818 * Here the array is only one element long, but you could ask for
819 * more than one scanline at a time if that's more convenient.
822 //printf( "scanlines: %d\n",cinfo.output_scanline);
823 (void) jpeg_read_scanlines(&cinfo, buffer, 1);
824 #if defined(GDCM_WORDS_BIGENDIAN) && (CMAKE_BITS_IN_JSAMPLE != 8)
825 uint16_t *buffer16 = (uint16_t*)*buffer;
826 uint16_t *pimage16 = (uint16_t*)pimage;
827 for(unsigned int i=0;i<rowsize/2;i++)
828 pimage16[i] = (buffer16[i] >> 8) | (buffer16[i] << 8 );
830 memcpy( pimage, *buffer,rowsize);
831 #endif //GDCM_WORDS_BIGENDIAN
835 /* Step 7: Finish decompression */
836 #ifdef GDCM_JPG_DEBUG
837 printf("Entree Step 7\n");
838 #endif //GDCM_JPG_DEBUG
840 input = (JOCTET *)cinfo.src->next_input_byte;
842 (void) jpeg_finish_decompress(&cinfo);
844 /* We can ignore the return value since suspension is not possible
845 * with the stdio data source.
848 /* Step 8: Release JPEG decompression object */
850 #ifdef GDCM_JPG_DEBUG
851 printf("Entree Step 8\n");
852 #endif //GDCM_JPG_DEBUG
854 /* This is an important step since it will release a good deal of memory. */
856 jpeg_destroy_decompress(&cinfo);
859 /* After finish_decompress, we can close the input file.
860 * Here we postpone it until after no more JPEG errors are possible,
861 * so as to simplify the setjmp error logic above. (Actually, I don't
862 * think that jpeg_destroy can do an error exit, but why assume anything...)
865 /* At this point you may want to check to see whether any corrupt-data
866 * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
869 /* And we're done! */
870 *howManyRead += input - input_buffer;
871 *howManyWritten += pimage - (char *)image_buffer;
876 } // end namespace gdcm