1 /*=========================================================================
4 Module: $RCSfile: gdcmJpeg.cxx,v $
6 Date: $Date: 2004/10/18 02:17:07 $
7 Version: $Revision: 1.27 $
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 =========================================================================*/
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".
92 /******************** JPEG COMPRESSION SAMPLE INTERFACE *******************/
94 /* This half of the example shows how to feed data into the JPEG compressor.
95 * We present a minimal version that does not worry about refinements such
96 * as error recovery (the JPEG code will just exit() if it gets an error).
100 * IMAGE DATA FORMATS:
102 * The standard input image format is a rectangular array of pixels, with
103 * each pixel having the same number of "component" values (color channels).
104 * Each pixel row is an array of JSAMPLEs (which typically are unsigned chars).
105 * If you are working with color data, then the color values for each pixel
106 * must be adjacent in the row; for example, R,G,B,R,G,B,R,G,B,... for 24-bit
109 * For this example, we'll assume that this data structure matches the way
110 * our application has stored the image in memory, so we can just pass a
111 * pointer to our image buffer. In particular, let's say that the image is
112 * RGB color and is described by:
116 //extern JSAMPLE * image_buffer; /* Points to large array of R,G,B-order data */
117 //extern int image_height; /* Number of rows in image */
118 //extern int image_width; /* Number of columns in image */
123 * Sample routine for JPEG compression. We assume that the target file name
124 * and a compression quality factor are passed in.
129 * \brief routine for JPEG decompression
130 * @param fp pointer to an already open file descriptor
131 * 8 significant bits per pixel
132 * @param im_buf Points to array (of R,G,B-order) data to compress
133 * @param quality compression quality
134 * @param image_height Number of rows in image
135 * @param image_width Number of columns in image
136 * @return 1 on success, 0 on error
139 bool gdcm_write_JPEG_file (FILE* fp, void* im_buf,
140 int image_width, int image_height, int quality)
143 JSAMPLE* image_buffer = (JSAMPLE*) im_buf;
145 /* This struct contains the JPEG compression parameters and pointers to
146 * working space (which is allocated as needed by the JPEG library).
147 * It is possible to have several such structures, representing multiple
148 * compression/decompression processes, in existence at once. We refer
149 * to any one struct (and its associated working data) as a "JPEG object".
151 struct jpeg_compress_struct cinfo;
152 /* This struct represents a JPEG error handler. It is declared separately
153 * because applications often want to supply a specialized error handler
154 * (see the second half of this file for an example). But here we just
155 * take the easy way out and use the standard error handler, which will
156 * print a message on stderr and call exit() if compression fails.
157 * Note that this struct must live as long as the main JPEG parameter
158 * struct, to avoid dangling-pointer problems.
160 struct jpeg_error_mgr jerr;
162 //FILE* outfile; /* target FILE* /
163 JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
164 int row_stride; /* physical row width in image buffer */
166 /* Step 1: allocate and initialize JPEG compression object */
168 /* We have to set up the error handler first, in case the initialization
169 * step fails. (Unlikely, but it could happen if you are out of memory.)
170 * This routine fills in the contents of struct jerr, and returns jerr's
171 * address which we place into the link field in cinfo.
173 cinfo.err = jpeg_std_error(&jerr);
174 /* Now we can initialize the JPEG compression object. */
175 jpeg_create_compress(&cinfo);
177 /* Step 2: specify data destination (eg, a file) */
178 /* Note: steps 2 and 3 can be done in either order. */
180 /* Here we use the library-supplied code to send compressed data to a
181 * stdio stream. You can also write your own code to do something else.
182 * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
183 * requires it in order to write binary files.
185 // if ((outfile = fopen(filename, "wb")) == NULL) {
186 // fprintf(stderr, "can't open %s\n", filename);
190 jpeg_stdio_dest(&cinfo, fp);
192 /* Step 3: set parameters for compression */
194 /* First we supply a description of the input image.
195 * Four fields of the cinfo struct must be filled in:
197 cinfo.image_width = image_width;/* image width and height, in pixels */
198 cinfo.image_height = image_height;
199 cinfo.input_components = 3; /* # of color components per pixel */
200 cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
201 /* Now use the library's routine to set default compression parameters.
202 * (You must set at least cinfo.in_color_space before calling this,
203 * since the defaults depend on the source color space.)
205 jpeg_set_defaults(&cinfo);
206 /* Now you can set any non-default parameters you wish to.
207 * Here we just illustrate the use of quality (quantization table) scaling:
209 jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
211 /* Step 4: Start compressor */
213 /* TRUE ensures that we will write a complete interchange-JPEG file.
214 * Pass TRUE unless you are very sure of what you're doing.
216 jpeg_start_compress(&cinfo, TRUE);
218 /* Step 5: while (scan lines remain to be written) */
219 /* jpeg_write_scanlines(...); */
221 /* Here we use the library's state variable cinfo.next_scanline as the
222 * loop counter, so that we don't have to keep track ourselves.
223 * To keep things simple, we pass one scanline per call; you can pass
224 * more if you wish, though.
226 row_stride = image_width * 3;/* JSAMPLEs per row in image_buffer */
228 while (cinfo.next_scanline < cinfo.image_height) {
229 /* jpeg_write_scanlines expects an array of pointers to scanlines.
230 * Here the array is only one element long, but you could pass
231 * more than one scanline at a time if that's more convenient.
233 row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride];
235 (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
238 /* Step 6: Finish compression */
240 jpeg_finish_compress(&cinfo);
242 /* After finish_compress, we can close the output file. */
244 // fclose(fp); --> the caller will close (multiframe treatement)
246 /* Step 7: release JPEG compression object */
248 /* This is an important step since it will release a good deal of memory. */
249 jpeg_destroy_compress(&cinfo);
251 /* And we're done! */
261 * In the above loop, we ignored the return value of jpeg_write_scanlines,
262 * which is the number of scanlines actually written. We could get away
263 * with this because we were only relying on the value of cinfo.next_scanline,
264 * which will be incremented correctly. If you maintain additional loop
265 * variables then you should be careful to increment them properly.
266 * Actually, for output to a stdio stream you needn't worry, because
267 * then jpeg_write_scanlines will write all the lines passed (or else exit
268 * with a fatal error). Partial writes can only occur if you use a data
269 * destination module that can demand suspension of the compressor.
270 * (If you don't know what that's for, you don't need it.)
272 * If the compressor requires full-image buffers (for entropy-coding
273 * optimization or a multi-scan JPEG file), it will create temporary
274 * files for anything that doesn't fit within the maximum-memory setting.
275 * (Note that temp files are NOT needed if you use the default parameters.)
276 * On some systems you may need to set up a signal handler to ensure that
277 * temporary files are deleted if the program is interrupted. See libjpeg.doc.
279 * Scanlines MUST be supplied in top-to-bottom order if you want your JPEG
280 * files to be compatible with everyone else's. If you cannot readily read
281 * your data in that order, you'll need an intermediate array to hold the
282 * image. See rdtarga.c or rdbmp.c for examples of handling bottom-to-top
283 * source data using the JPEG code's internal virtual-array mechanisms.
288 /******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/
290 /* This half of the example shows how to read data from the JPEG decompressor.
291 * It's a bit more refined than the above, in that we show:
292 * (a) how to modify the JPEG library's standard error-reporting behavior;
293 * (b) how to allocate workspace using the library's memory manager.
295 * Just to make this example a little different from the first one, we'll
296 * assume that we do not intend to put the whole image into an in-memory
297 * buffer, but to send it line-by-line someplace else. We need a one-
298 * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG
299 * memory manager allocate it for us. This approach is actually quite useful
300 * because we don't need to remember to deallocate the buffer separately: it
301 * will go away automatically when the JPEG object is cleaned up.
307 * The JPEG library's standard error handler (jerror.c) is divided into
308 * several "methods" which you can override individually. This lets you
309 * adjust the behavior without duplicating a lot of code, which you might
310 * have to update with each future release.
312 * Our example here shows how to override the "error_exit" method so that
313 * control is returned to the library's caller when a fatal error occurs,
314 * rather than calling exit() as the standard error_exit method does.
316 * We use C's setjmp/longjmp facility to return control. This means that the
317 * routine which calls the JPEG library must first execute a setjmp() call to
318 * establish the return point. We want the replacement error_exit to do a
319 * longjmp(). But we need to make the setjmp buffer accessible to the
320 * error_exit routine. To do this, we make a private extension of the
321 * standard JPEG error handler object. (If we were using C++, we'd say we
322 * were making a subclass of the regular error handler.)
324 * Here's the extended error handler struct:
327 //-----------------------------------------------------------------------------
328 struct my_error_mgr {
329 struct jpeg_error_mgr pub; /* "public" fields */
330 jmp_buf setjmp_buffer; /* for return to caller */
333 //-----------------------------------------------------------------------------
334 typedef struct my_error_mgr* my_error_ptr;
337 * Here's the routine that will replace the standard error_exit method:
339 METHODDEF(void) my_error_exit (j_common_ptr cinfo) {
340 /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
341 my_error_ptr myerr = (my_error_ptr) cinfo->err;
343 /* Always display the message. */
344 /* We could postpone this until after returning, if we chose. */
345 (*cinfo->err->output_message) (cinfo);
347 /* Return control to the setjmp point */
348 longjmp(myerr->setjmp_buffer, 1);
351 //-----------------------------------------------------------------------------
353 * Sample routine for JPEG decompression. We assume that the source file name
354 * is passed in. We want to return 1 on success, 0 on error.
358 * \brief routine for JPEG decompression
359 * @param fp pointer to an already open file descriptor
360 * 8 significant bits per pixel
361 * @param image_buffer to receive uncompressed pixels
362 * @return 1 on success, 0 on error
365 bool gdcm_read_JPEG_file ( FILE* fp, void* image_buffer )
369 /* This struct contains the JPEG decompression parameters and pointers to
370 * working space (which is allocated as needed by the JPEG library).
372 struct jpeg_decompress_struct cinfo;
374 /* -------------- inside, we found :
375 * JDIMENSION image_width; // input image width
376 * JDIMENSION image_height; // input image height
377 * int input_components; // nb of color components in input image
378 * J_COLOR_SPACE in_color_space; // colorspace of input image
379 * double input_gamma; // image gamma of input image
382 /* We use our private extension JPEG error handler.
383 * Note that this struct must live as long as the main JPEG parameter
384 * struct, to avoid dangling-pointer problems.
386 struct my_error_mgr jerr;
389 JSAMPARRAY buffer;/* Output row buffer */
393 // typedef unsigned char JSAMPLE;
394 // typedef JSAMPLE FAR *JSAMPROW;/* ptr to one image row of pixel samples. */
395 // typedef JSAMPROW *JSAMPARRAY;/* ptr to some rows (a 2-D sample array) */
396 // typedef JSAMPARRAY *JSAMPIMAGE;/* a 3-D sample array: top index is color */
398 int row_stride;/* physical row width in output buffer */
400 #ifdef GDCM_JPG_DEBUG
401 printf("entree dans File::gdcm_read_JPEG_file (i.e. 8), depuis gdcmJpeg\n");
402 #endif //GDCM_JPG_DEBUG
404 /* In this example we want to open the input file before doing anything else,
405 * so that the setjmp() error recovery below can assume the file is open.
406 * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
407 * requires it in order to read binary files.
410 /* Step 1: allocate and initialize JPEG decompression object */
411 #ifdef GDCM_JPG_DEBUG
412 printf("Entree Step 1\n");
413 #endif //GDCM_JPG_DEBUG
415 /* We set up the normal JPEG error routines, then override error_exit. */
417 cinfo.err = jpeg_std_error(&jerr.pub);
418 jerr.pub.error_exit = my_error_exit;
420 /* Establish the setjmp return context for my_error_exit to use. */
421 if (setjmp(jerr.setjmp_buffer))
423 /* If we get here, the JPEG code has signaled an error.
424 * We need to clean up the JPEG object, close the input file, and return.
426 jpeg_destroy_decompress(&cinfo);
429 /* Now we can initialize the JPEG decompression object. */
430 jpeg_create_decompress(&cinfo);
432 /* Step 2: specify data source (eg, a file) */
433 #ifdef GDCM_JPG_DEBUG
434 printf("Entree Step 2\n");
435 #endif //GDCM_JPG_DEBUG
437 jpeg_stdio_src(&cinfo, fp);
439 /* Step 3: read file parameters with jpeg_read_header() */
440 #ifdef GDCM_JPG_DEBUG
441 printf("Entree Step 3\n");
442 #endif //GDCM_JPG_DEBUG
444 (void) jpeg_read_header(&cinfo, TRUE);
446 /* We can ignore the return value from jpeg_read_header since
447 * (a) suspension is not possible with the stdio data source, and
448 * (b) we passed TRUE to reject a tables-only JPEG file as an error.
449 * See libjpeg.doc for more info.
452 // prevent the library from performing any color space conversion
453 if( cinfo.process == JPROC_LOSSLESS )
455 cinfo.jpeg_color_space = JCS_UNKNOWN;
456 cinfo.out_color_space = JCS_UNKNOWN;
460 #ifdef GDCM_JPG_DEBUG
461 printf("--------------Header contents :----------------\n");
462 printf("image_width %d image_height %d\n",
463 cinfo.image_width , cinfo.image_height);
464 printf("bits of precision in image data %d \n",
465 cinfo.output_components);
466 printf("nb of color components returned %d \n",
467 cinfo.data_precision);
468 #endif //GDCM_JPG_DEBUG
472 * JDIMENSION image_width; // input image width
473 * JDIMENSION image_height; // input image height
474 * int output_components; // # of color components returned
475 * J_COLOR_SPACE in_color_space; // colorspace of input image
476 * double input_gamma; // image gamma of input image
477 * int data_precision; // bits of precision in image data
480 /* Step 4: set parameters for decompression */
481 #ifdef GDCM_JPG_DEBUG
482 printf("Entree Step 4\n");
483 #endif //GDCM_JPG_DEBUG
484 /* In this example, we don't need to change any of the defaults set by
485 * jpeg_read_header(), so we do nothing here.
488 /* Step 5: Start decompressor */
489 #ifdef GDCM_JPG_DEBUG
490 printf("Entree Step 5\n");
491 #endif //GDCM_JPG_DEBUG
493 (void) jpeg_start_decompress(&cinfo);
494 /* We can ignore the return value since suspension is not possible
495 * with the stdio data source.
498 /* We may need to do some setup of our own at this point before reading
499 * the data. After jpeg_start_decompress() we have the correct scaled
500 * output image dimensions available, as well as the output colormap
501 * if we asked for color quantization.
502 * In this example, we need to make an output work buffer of the right size.
505 /* JSAMPLEs per row in output buffer */
506 row_stride = cinfo.output_width * cinfo.output_components;
508 #ifdef GDCM_JPG_DEBUG
509 printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n",
510 cinfo.output_width, cinfo.output_components,row_stride);
511 #endif //GDCM_JPG_DEBUG
513 /* Make a one-row-high sample array that will go away when done with image */
514 buffer = (*cinfo.mem->alloc_sarray)
515 ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
517 /* Step 6: while (scan lines remain to be read) */
518 #ifdef GDCM_JPG_DEBUG
519 printf("Entree Step 6\n");
520 #endif //GDCM_JPG_DEBUG
521 /* jpeg_read_scanlines(...); */
523 /* Here we use the library's state variable cinfo.output_scanline as the
524 * loop counter, so that we don't have to keep track ourselves.
526 #ifdef GDCM_JPG_DEBUG
527 printf ("cinfo.output_height %d cinfo.output_width %d\n",
528 cinfo.output_height,cinfo.output_width);
529 #endif //GDCM_JPG_DEBUG
530 pimage=(char *)image_buffer;
532 int bufsize = cinfo.output_width * cinfo.output_components;
533 size_t rowsize = bufsize * sizeof(JSAMPLE);
535 while (cinfo.output_scanline < cinfo.output_height) {
536 /* jpeg_read_scanlines expects an array of pointers to scanlines.
537 * Here the array is only one element long, but you could ask for
538 * more than one scanline at a time if that's more convenient.
541 //printf( "scanlines: %d\n",cinfo.output_scanline);
542 (void) jpeg_read_scanlines(&cinfo, buffer, 1);
543 memcpy( pimage, *buffer,rowsize);
547 /* Step 7: Finish decompression */
548 #ifdef GDCM_JPG_DEBUG
549 printf("Entree Step 7\n");
550 #endif //GDCM_JPG_DEBUG
552 (void) jpeg_finish_decompress(&cinfo);
554 /* We can ignore the return value since suspension is not possible
555 * with the stdio data source.
558 /* Step 8: Release JPEG decompression object */
560 #ifdef GDCM_JPG_DEBUG
561 printf("Entree Step 8\n");
562 #endif //GDCM_JPG_DEBUG
564 /* This is an important step since it will release a good deal of memory. */
566 jpeg_destroy_decompress(&cinfo);
568 /* After finish_decompress, we can close the input file.
569 * Here we postpone it until after no more JPEG errors are possible,
570 * so as to simplify the setjmp error logic above. (Actually, I don't
571 * think that jpeg_destroy can do an error exit, but why assume anything...)
574 /* At this point you may want to check to see whether any corrupt-data
575 * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
578 /* And we're done! */
587 * In the above code, we ignored the return value of jpeg_read_scanlines,
588 * which is the number of scanlines actually read. We could get away with
589 * this because we asked for only one line at a time and we weren't using
590 * a suspending data source. See libjpeg.doc for more info.
592 * We cheated a bit by calling alloc_sarray() after jpeg_start_decompress();
593 * we should have done it beforehand to ensure that the space would be
594 * counted against the JPEG max_memory setting. In some systems the above
595 * code would risk an out-of-memory error. However, in general we don't
596 * know the output image dimensions before jpeg_start_decompress(), unless we
597 * call jpeg_calc_output_dimensions(). See libjpeg.doc for more about this.
599 * Scanlines are returned in the same order as they appear in the JPEG file,
600 * which is standardly top-to-bottom. If you must emit data bottom-to-top,
601 * you can use one of the virtual arrays provided by the JPEG memory manager
602 * to invert the data. See wrbmp.c for an example.
604 * As with compression, some operating modes may require temporary files.
605 * On some systems you may need to set up a signal handler to ensure that
606 * temporary files are deleted if the program is interrupted. See libjpeg.doc.
609 //----------------------------------------------------------------------------
611 } // end namespace gdcm