2 //-----------------------------------------------------------------------------
6 #define BITS_IN_JSAMPLE 8
9 #define GDCM_jpr_DEBUG 0
13 DICOM provides a mechanism for supporting the use of JPEG Image Compression
14 through the Encapsulated Format (see PS 3.3 of the DICOM Standard).
15 Annex A defines a number of Transfer Syntaxes which reference
16 the JPEG Standard and provide a number of lossless (bit preserving)
17 and lossy compression schemes.
18 In order to facilitate interoperability of implementations conforming
19 to the DICOM Standard which elect to use one or more
20 of the Transfer Syntaxes for JPEG Image Compression, the following policy is specified:
22 Any implementation which conforms to the DICOM Standard and has elected
23 to support any one of the Transfer Syntaxes for lossless JPEG Image Compression,
24 shall support the following lossless compression:
25 The subset (first-order horizontal prediction [Selection Value 1) of JPEG Process 14
26 (DPCM, non-hierarchical with Huffman coding) (see Annex F of the DICOM Standard).
28 Any implementation which conforms to the DICOM Standard and has elected
29 to support any one of the Transfer Syntaxes for 8-bit lossy JPEG Image Compression,
30 shall support the JPEG Baseline Compression (coding Process 1).
32 Any implementation which conforms to the DICOM Standard and has elected
33 to support any one of the Transfer Syntaxes for 12-bit lossy JPEG Image Compression,
34 shall support the JPEG Compression Process 4.
36 Note: The DICOM conformance statement shall differentiate between implementations
37 that can simply receive JPEG encoded images and those that can receive and process
38 JPEG encoded images (see PS 3.2 of the DICOM Standard).
40 The use of the DICOM Encapsulated Format to support JPEG Compressed Pixel Data
41 implies that the Data Elements which are related to the Native Format Pixel Data encoding
42 (e.g. Bits Allocated, Bits Stored, High Bit, Pixel Representation, Rows, Columns, etc.)
43 shall contain values which are consistent with the characteristics
44 of the uncompressed pixel data from which the compressed Data Stream was derived.
45 The Pixel Data characteristics included in the JPEG Interchange Format
46 shall be used to decode the compressed data stream.
48 Run Length Encoding Compression
50 DICOM provides a mechanism for supporting the use of Run Length Encoding (RLE)
51 Compression which is a byte oriented lossless compression scheme through
52 the encapsulated Format (see PS 3.3 of this Standard).
53 Annex G of the DICOM Standard defines RLE Compression and its Transfer Syntax.
55 Note: The RLE Compression algorithm described in Annex G
56 of the DICOM Standard is the compression used in
57 the TIFF 6.0 specification known as the "PackBits" scheme.
59 The use of the DICOM Encapsulated Format to support RLE Compressed Pixel Data
60 implies that the Data Elements which are related to the Native Format Pixel Data encoding (
61 e.g. Bits Allocated, Bits Stored, High Bit, Pixel Representation, Rows, Columns, etc.)
62 shall contain values which are consistent with the characteristics
63 of the uncompressed pixel data from which the compressed data is derived
67 * <setjmp.h> is used for the optional error recovery mechanism shown in
68 * the second part of the example.
72 * Include file for users of JPEG library.
73 * You will need to have included system headers that define at least
74 * the typedefs FILE and size_t before you can include jpeglib.h.
75 * (stdio.h is sufficient on ANSI-conforming systems.)
76 * You may also wish to include "jerror.h".
85 /******************** JPEG COMPRESSION SAMPLE INTERFACE *******************/
87 /* This half of the example shows how to feed data into the JPEG compressor.
88 * We present a minimal version that does not worry about refinements such
89 * as error recovery (the JPEG code will just exit() if it gets an error).
95 * The standard input image format is a rectangular array of pixels, with
96 * each pixel having the same number of "component" values (color channels).
97 * Each pixel row is an array of JSAMPLEs (which typically are unsigned chars).
98 * If you are working with color data, then the color values for each pixel
99 * must be adjacent in the row; for example, R,G,B,R,G,B,R,G,B,... for 24-bit
102 * For this example, we'll assume that this data structure matches the way
103 * our application has stored the image in memory, so we can just pass a
104 * pointer to our image buffer. In particular, let's say that the image is
105 * RGB color and is described by:
110 //extern JSAMPLE * image_buffer; /* Points to large array of R,G,B-order data */
111 //extern int image_height; /* Number of rows in image */
112 //extern int image_width; /* Number of columns in image */
117 * Sample routine for JPEG compression. We assume that the target file name
118 * and a compression quality factor are passed in.
123 * \brief routine for JPEG decompression
124 * @param fp pointer to an already open file descriptor
125 * 8 significant bits per pixel
126 * @param image_buffer Points to array (of R,G,B-order) data to compress
127 * @param quality compression quality
128 * @param image_height Number of rows in image
129 * @param image_width Number of columns in image
130 * @return 1 on success, 0 on error
133 bool gdcm_write_JPEG_file (FILE *fp, void * im_buf,
134 int image_width, int image_height, int quality)
137 JSAMPLE* image_buffer = (JSAMPLE*) im_buf;
139 /* This struct contains the JPEG compression parameters and pointers to
140 * working space (which is allocated as needed by the JPEG library).
141 * It is possible to have several such structures, representing multiple
142 * compression/decompression processes, in existence at once. We refer
143 * to any one struct (and its associated working data) as a "JPEG object".
145 struct jpeg_compress_struct cinfo;
146 /* This struct represents a JPEG error handler. It is declared separately
147 * because applications often want to supply a specialized error handler
148 * (see the second half of this file for an example). But here we just
149 * take the easy way out and use the standard error handler, which will
150 * print a message on stderr and call exit() if compression fails.
151 * Note that this struct must live as long as the main JPEG parameter
152 * struct, to avoid dangling-pointer problems.
154 struct jpeg_error_mgr jerr;
156 //FILE * outfile; /* target file */
157 JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
158 int row_stride; /* physical row width in image buffer */
160 /* Step 1: allocate and initialize JPEG compression object */
162 /* We have to set up the error handler first, in case the initialization
163 * step fails. (Unlikely, but it could happen if you are out of memory.)
164 * This routine fills in the contents of struct jerr, and returns jerr's
165 * address which we place into the link field in cinfo.
167 cinfo.err = jpeg_std_error(&jerr);
168 /* Now we can initialize the JPEG compression object. */
169 jpeg_create_compress(&cinfo);
171 /* Step 2: specify data destination (eg, a file) */
172 /* Note: steps 2 and 3 can be done in either order. */
174 /* Here we use the library-supplied code to send compressed data to a
175 * stdio stream. You can also write your own code to do something else.
176 * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
177 * requires it in order to write binary files.
179 // if ((outfile = fopen(filename, "wb")) == NULL) {
180 // fprintf(stderr, "can't open %s\n", filename);
184 jpeg_stdio_dest(&cinfo, fp);
186 /* Step 3: set parameters for compression */
188 /* First we supply a description of the input image.
189 * Four fields of the cinfo struct must be filled in:
191 cinfo.image_width = image_width;/* image width and height, in pixels */
192 cinfo.image_height = image_height;
193 cinfo.input_components = 3; /* # of color components per pixel */
194 cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
195 /* Now use the library's routine to set default compression parameters.
196 * (You must set at least cinfo.in_color_space before calling this,
197 * since the defaults depend on the source color space.)
199 jpeg_set_defaults(&cinfo);
200 /* Now you can set any non-default parameters you wish to.
201 * Here we just illustrate the use of quality (quantization table) scaling:
203 jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
205 /* Step 4: Start compressor */
207 /* TRUE ensures that we will write a complete interchange-JPEG file.
208 * Pass TRUE unless you are very sure of what you're doing.
210 jpeg_start_compress(&cinfo, TRUE);
212 /* Step 5: while (scan lines remain to be written) */
213 /* jpeg_write_scanlines(...); */
215 /* Here we use the library's state variable cinfo.next_scanline as the
216 * loop counter, so that we don't have to keep track ourselves.
217 * To keep things simple, we pass one scanline per call; you can pass
218 * more if you wish, though.
220 row_stride = image_width * 3;/* JSAMPLEs per row in image_buffer */
222 while (cinfo.next_scanline < cinfo.image_height) {
223 /* jpeg_write_scanlines expects an array of pointers to scanlines.
224 * Here the array is only one element long, but you could pass
225 * more than one scanline at a time if that's more convenient.
227 row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride];
229 (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
232 /* Step 6: Finish compression */
234 jpeg_finish_compress(&cinfo);
236 /* After finish_compress, we can close the output file. */
238 // fclose(fp); --> the caller will close (multiframe treatement)
240 /* Step 7: release JPEG compression object */
242 /* This is an important step since it will release a good deal of memory. */
243 jpeg_destroy_compress(&cinfo);
245 /* And we're done! */
253 * In the above loop, we ignored the return value of jpeg_write_scanlines,
254 * which is the number of scanlines actually written. We could get away
255 * with this because we were only relying on the value of cinfo.next_scanline,
256 * which will be incremented correctly. If you maintain additional loop
257 * variables then you should be careful to increment them properly.
258 * Actually, for output to a stdio stream you needn't worry, because
259 * then jpeg_write_scanlines will write all the lines passed (or else exit
260 * with a fatal error). Partial writes can only occur if you use a data
261 * destination module that can demand suspension of the compressor.
262 * (If you don't know what that's for, you don't need it.)
264 * If the compressor requires full-image buffers (for entropy-coding
265 * optimization or a multi-scan JPEG file), it will create temporary
266 * files for anything that doesn't fit within the maximum-memory setting.
267 * (Note that temp files are NOT needed if you use the default parameters.)
268 * On some systems you may need to set up a signal handler to ensure that
269 * temporary files are deleted if the program is interrupted. See libjpeg.doc.
271 * Scanlines MUST be supplied in top-to-bottom order if you want your JPEG
272 * files to be compatible with everyone else's. If you cannot readily read
273 * your data in that order, you'll need an intermediate array to hold the
274 * image. See rdtarga.c or rdbmp.c for examples of handling bottom-to-top
275 * source data using the JPEG code's internal virtual-array mechanisms.
280 /******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/
282 /* This half of the example shows how to read data from the JPEG decompressor.
283 * It's a bit more refined than the above, in that we show:
284 * (a) how to modify the JPEG library's standard error-reporting behavior;
285 * (b) how to allocate workspace using the library's memory manager.
287 * Just to make this example a little different from the first one, we'll
288 * assume that we do not intend to put the whole image into an in-memory
289 * buffer, but to send it line-by-line someplace else. We need a one-
290 * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG
291 * memory manager allocate it for us. This approach is actually quite useful
292 * because we don't need to remember to deallocate the buffer separately: it
293 * will go away automatically when the JPEG object is cleaned up.
299 * The JPEG library's standard error handler (jerror.c) is divided into
300 * several "methods" which you can override individually. This lets you
301 * adjust the behavior without duplicating a lot of code, which you might
302 * have to update with each future release.
304 * Our example here shows how to override the "error_exit" method so that
305 * control is returned to the library's caller when a fatal error occurs,
306 * rather than calling exit() as the standard error_exit method does.
308 * We use C's setjmp/longjmp facility to return control. This means that the
309 * routine which calls the JPEG library must first execute a setjmp() call to
310 * establish the return point. We want the replacement error_exit to do a
311 * longjmp(). But we need to make the setjmp buffer accessible to the
312 * error_exit routine. To do this, we make a private extension of the
313 * standard JPEG error handler object. (If we were using C++, we'd say we
314 * were making a subclass of the regular error handler.)
316 * Here's the extended error handler struct:
319 //-----------------------------------------------------------------------------
320 struct my_error_mgr {
321 struct jpeg_error_mgr pub; /* "public" fields */
322 jmp_buf setjmp_buffer; /* for return to caller */
325 //-----------------------------------------------------------------------------
326 typedef struct my_error_mgr * my_error_ptr;
329 * Here's the routine that will replace the standard error_exit method:
331 METHODDEF(void) my_error_exit (j_common_ptr cinfo) {
332 /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
333 my_error_ptr myerr = (my_error_ptr) cinfo->err;
335 /* Always display the message. */
336 /* We could postpone this until after returning, if we chose. */
337 (*cinfo->err->output_message) (cinfo);
339 /* Return control to the setjmp point */
340 longjmp(myerr->setjmp_buffer, 1);
343 //-----------------------------------------------------------------------------
345 * Sample routine for JPEG decompression. We assume that the source file name
346 * is passed in. We want to return 1 on success, 0 on error.
351 * \brief routine for JPEG decompression
352 * @param fp pointer to an already open file descriptor
353 * 8 significant bits per pixel
354 * @param image_buffer to receive uncompressed pixels
355 * @return 1 on success, 0 on error
358 bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) {
361 /* This struct contains the JPEG decompression parameters and pointers to
362 * working space (which is allocated as needed by the JPEG library).
364 struct jpeg_decompress_struct cinfo;
366 /* -------------- inside, we found :
367 * JDIMENSION image_width; // input image width
368 * JDIMENSION image_height; // input image height
369 * int input_components; // nb of color components in input image
370 * J_COLOR_SPACE in_color_space; // colorspace of input image
371 * double input_gamma; // image gamma of input image
374 /* We use our private extension JPEG error handler.
375 * Note that this struct must live as long as the main JPEG parameter
376 * struct, to avoid dangling-pointer problems.
378 struct my_error_mgr jerr;
381 JSAMPARRAY buffer;/* Output row buffer */
385 // typedef unsigned char JSAMPLE;
386 // typedef JSAMPLE FAR *JSAMPROW;/* ptr to one image row of pixel samples. */
387 // typedef JSAMPROW *JSAMPARRAY;/* ptr to some rows (a 2-D sample array) */
388 // typedef JSAMPARRAY *JSAMPIMAGE;/* a 3-D sample array: top index is color */
390 int row_stride;/* physical row width in output buffer */
392 #ifdef GDCM_JPG_DEBUG
393 printf("entree dans gdcmFile::gdcm_read_JPEG_file (i.e. 8), depuis gdcmJpeg\n");
394 #endif //GDCM_JPG_DEBUG
396 /* In this example we want to open the input file before doing anything else,
397 * so that the setjmp() error recovery below can assume the file is open.
398 * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
399 * requires it in order to read binary files.
402 /* Step 1: allocate and initialize JPEG decompression object */
403 #ifdef GDCM_JPG_DEBUG
404 printf("Entree Step 1\n");
405 #endif //GDCM_JPG_DEBUG
407 /* We set up the normal JPEG error routines, then override error_exit. */
409 cinfo.err = jpeg_std_error(&jerr.pub);
410 jerr.pub.error_exit = my_error_exit;
412 /* Establish the setjmp return context for my_error_exit to use. */
413 if (setjmp(jerr.setjmp_buffer)) {
414 /* If we get here, the JPEG code has signaled an error.
415 * We need to clean up the JPEG object, close the input file, and return.
417 jpeg_destroy_decompress(&cinfo);
420 /* Now we can initialize the JPEG decompression object. */
421 jpeg_create_decompress(&cinfo);
423 /* Step 2: specify data source (eg, a file) */
424 #ifdef GDCM_JPG_DEBUG
425 printf("Entree Step 2\n");
426 #endif //GDCM_JPG_DEBUG
428 jpeg_stdio_src(&cinfo, fp);
430 /* Step 3: read file parameters with jpeg_read_header() */
431 #ifdef GDCM_JPG_DEBUG
432 printf("Entree Step 3\n");
433 #endif //GDCM_JPG_DEBUG
435 (void) jpeg_read_header(&cinfo, TRUE);
437 /* We can ignore the return value from jpeg_read_header since
438 * (a) suspension is not possible with the stdio data source, and
439 * (b) we passed TRUE to reject a tables-only JPEG file as an error.
440 * See libjpeg.doc for more info.
443 #ifdef GDCM_JPG_DEBUG
444 printf("--------------Header contents :----------------\n");
445 printf("image_width %d image_height %d\n",
446 cinfo.image_width , cinfo.image_height);
447 printf("bits of precision in image data %d \n",
448 cinfo.output_components);
449 printf("nb of color components returned %d \n",
450 cinfo.data_precision);
451 #endif //GDCM_JPG_DEBUG
455 * JDIMENSION image_width; // input image width
456 * JDIMENSION image_height; // input image height
457 * int output_components; // # of color components returned
458 * J_COLOR_SPACE in_color_space; // colorspace of input image
459 * double input_gamma; // image gamma of input image
460 * int data_precision; // bits of precision in image data
463 /* Step 4: set parameters for decompression */
464 #ifdef GDCM_JPG_DEBUG
465 printf("Entree Step 4\n");
466 #endif //GDCM_JPG_DEBUG
467 /* In this example, we don't need to change any of the defaults set by
468 * jpeg_read_header(), so we do nothing here.
471 /* Step 5: Start decompressor */
472 #ifdef GDCM_JPG_DEBUG
473 printf("Entree Step 5\n");
474 #endif //GDCM_JPG_DEBUG
476 (void) jpeg_start_decompress(&cinfo);
477 /* We can ignore the return value since suspension is not possible
478 * with the stdio data source.
481 /* We may need to do some setup of our own at this point before reading
482 * the data. After jpeg_start_decompress() we have the correct scaled
483 * output image dimensions available, as well as the output colormap
484 * if we asked for color quantization.
485 * In this example, we need to make an output work buffer of the right size.
488 /* JSAMPLEs per row in output buffer */
489 row_stride = cinfo.output_width * cinfo.output_components;
491 #ifdef GDCM_JPG_DEBUG
492 printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n",
493 cinfo.output_width, cinfo.output_components,row_stride);
494 #endif //GDCM_JPG_DEBUG
496 /* Make a one-row-high sample array that will go away when done with image */
497 buffer = (*cinfo.mem->alloc_sarray)
498 ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
500 /* Step 6: while (scan lines remain to be read) */
501 #ifdef GDCM_JPG_DEBUG
502 printf("Entree Step 6\n");
503 #endif //GDCM_JPG_DEBUG
504 /* jpeg_read_scanlines(...); */
506 /* Here we use the library's state variable cinfo.output_scanline as the
507 * loop counter, so that we don't have to keep track ourselves.
509 #ifdef GDCM_JPG_DEBUG
510 printf ("cinfo.output_height %d cinfo.output_width %d\n",
511 cinfo.output_height,cinfo.output_width);
512 #endif //GDCM_JPG_DEBUG
513 pimage=(char *)image_buffer;
515 while (cinfo.output_scanline < cinfo.output_height) {
516 /* jpeg_read_scanlines expects an array of pointers to scanlines.
517 * Here the array is only one element long, but you could ask for
518 * more than one scanline at a time if that's more convenient.
521 // l'image est deja allouée (et passée en param)
522 // on ecrit directement les pixels
523 // (on DEVRAIT pouvoir)
525 //(void) jpeg_read_scanlines(&cinfo, pimage, 1);
527 (void) jpeg_read_scanlines(&cinfo, buffer, 1);
529 if ( BITS_IN_JSAMPLE == 8) {
530 memcpy( pimage, buffer[0],row_stride);
533 memcpy( pimage, buffer[0],row_stride*2 ); // FIXME : *2 car 16 bits?!?
534 pimage+=row_stride*2; // FIXME : *2 car 16 bits?!?
538 /* Step 7: Finish decompression */
539 #ifdef GDCM_JPG_DEBUG
540 printf("Entree Step 7\n");
541 #endif //GDCM_JPG_DEBUG
543 (void) jpeg_finish_decompress(&cinfo);
545 /* We can ignore the return value since suspension is not possible
546 * with the stdio data source.
549 /* Step 8: Release JPEG decompression object */
551 #ifdef GDCM_JPG_DEBUG
552 printf("Entree Step 8\n");
553 #endif //GDCM_JPG_DEBUG
555 /* This is an important step since it will release a good deal of memory. */
557 jpeg_destroy_decompress(&cinfo);
559 /* After finish_decompress, we can close the input file.
560 * Here we postpone it until after no more JPEG errors are possible,
561 * so as to simplify the setjmp error logic above. (Actually, I don't
562 * think that jpeg_destroy can do an error exit, but why assume anything...)
565 /* At this point you may want to check to see whether any corrupt-data
566 * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
569 /* And we're done! */
578 * In the above code, we ignored the return value of jpeg_read_scanlines,
579 * which is the number of scanlines actually read. We could get away with
580 * this because we asked for only one line at a time and we weren't using
581 * a suspending data source. See libjpeg.doc for more info.
583 * We cheated a bit by calling alloc_sarray() after jpeg_start_decompress();
584 * we should have done it beforehand to ensure that the space would be
585 * counted against the JPEG max_memory setting. In some systems the above
586 * code would risk an out-of-memory error. However, in general we don't
587 * know the output image dimensions before jpeg_start_decompress(), unless we
588 * call jpeg_calc_output_dimensions(). See libjpeg.doc for more about this.
590 * Scanlines are returned in the same order as they appear in the JPEG file,
591 * which is standardly top-to-bottom. If you must emit data bottom-to-top,
592 * you can use one of the virtual arrays provided by the JPEG memory manager
593 * to invert the data. See wrbmp.c for an example.
595 * As with compression, some operating modes may require temporary files.
596 * On some systems you may need to set up a signal handler to ensure that
597 * temporary files are deleted if the program is interrupted. See libjpeg.doc.
600 //----------------------------------------------------------------------------