Program: gdcm
Module: $RCSfile: gdcmJpeg12.cxx,v $
Language: C++
- Date: $Date: 2004/10/12 04:35:46 $
- Version: $Revision: 1.21 $
+ Date: $Date: 2004/10/14 22:35:01 $
+ Version: $Revision: 1.22 $
Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
l'Image). All rights reserved. See Doc/License.txt or
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
-
#include "gdcmFile.h"
-/*
- * <setjmp.h> is used for the optional error recovery mechanism shown in
- * the second part of the example.
- */
-
-/*
- * Include file for users of JPEG library.
- * You will need to have included system headers that define at least
- * the typedefs FILE and size_t before you can include jpeglib.h.
- * (stdio.h is sufficient on ANSI-conforming systems.)
- * You may also wish to include "jerror.h".
- */
-
extern "C" {
#include "src/jpeg/libijg12/jconfig.h"
#include "src/jpeg/libijg12/jpeglib.h"
-#include <setjmp.h>
-}
-namespace gdcm
-{
-/******************** JPEG COMPRESSION SAMPLE INTERFACE *******************/
-
-//
-// TODO
-//
-
-bool gdcm_write_JPEG_file12 (FILE* fp, void* im_buff,
- int image_width, int image_heigh, int quality)
-{
- (void)fp;
- (void)im_buff;
- (void)image_width;
- (void)image_heigh;
- (void)quality;
-
- return true; //???
-}
-
-/******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/
-
-/* This half of the example shows how to read data from the JPEG decompressor.
- * It's a bit more refined than the above, in that we show:
- * (a) how to modify the JPEG library's standard error-reporting behavior;
- * (b) how to allocate workspace using the library's memory manager.
- *
- * Just to make this example a little different from the first one, we'll
- * assume that we do not intend to put the whole image into an in-memory
- * buffer, but to send it line-by-line someplace else. We need a one-
- * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG
- * memory manager allocate it for us. This approach is actually quite useful
- * because we don't need to remember to deallocate the buffer separately: it
- * will go away automatically when the JPEG object is cleaned up.
- */
-
-/*
- * ERROR HANDLING:
- *
- * The JPEG library's standard error handler (jerror.c) is divided into
- * several "methods" which you can override individually. This lets you
- * adjust the behavior without duplicating a lot of code, which you might
- * have to update with each future release.
- *
- * Our example here shows how to override the "error_exit" method so that
- * control is returned to the library's caller when a fatal error occurs,
- * rather than calling exit() as the standard error_exit method does.
- *
- * We use C's setjmp/longjmp facility to return control. This means that the
- * routine which calls the JPEG library must first execute a setjmp() call to
- * establish the return point. We want the replacement error_exit to do a
- * longjmp(). But we need to make the setjmp buffer accessible to the
- * error_exit routine. To do this, we make a private extension of the
- * standard JPEG error handler object. (If we were using C++, we'd say we
- * were making a subclass of the regular error handler.)
- *
- * Here's the extended error handler struct:
- */
-
-//-----------------------------------------------------------------------------
-struct my_error_mgr {
- struct jpeg_error_mgr pub; /* "public" fields */
- jmp_buf setjmp_buffer; /* for return to caller */
-};
-
-//-----------------------------------------------------------------------------
-typedef struct my_error_mgr * my_error_ptr;
-
-/*
- * Here's the routine that will replace the standard error_exit method:
- */
-METHODDEF(void) my_error_exit (j_common_ptr cinfo)
-{
- /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
- my_error_ptr myerr = (my_error_ptr) cinfo->err;
-
- /* Always display the message. */
- /* We could postpone this until after returning, if we chose. */
- (*cinfo->err->output_message) (cinfo);
-
- /* Return control to the setjmp point */
- longjmp(myerr->setjmp_buffer, 1);
-}
-
-
-//-----------------------------------------------------------------------------
-/*
- * Sample routine for JPEG decompression. We assume that the source file name
- * is passed in. We want to return 1 on success, 0 on error.
- */
-
- /**
- * \ingroup File
- * \brief routine for JPEG decompression
- * @param fp pointer to an already open file descriptor
- * 12 significant bits per pixel
- * @param image_buffer to receive uncompressed pixels
- * @return 1 on success, 0 on error
- */
-
-bool gdcm_read_JPEG_file12 ( FILE* fp,void* image_buffer )
-{
- char *pimage;
-
- /* This struct contains the JPEG decompression parameters and pointers to
- * working space (which is allocated as needed by the JPEG library).
- */
- struct jpeg_decompress_struct cinfo;
-
- /* -------------- inside, we found :
- * JDIMENSION image_width; // input image width
- * JDIMENSION image_height; // input image height
- * int input_components; // nb of color components in input image
- * J_COLOR_SPACE in_color_space;// colorspace of input image
- * double input_gamma; // image gamma of input image
- * -------------- */
-
- /* We use our private extension JPEG error handler.
- * Note that this struct must live as long as the main JPEG parameter
- * struct, to avoid dangling-pointer problems.
- */
- struct my_error_mgr jerr;
- /* More stuff */
-
- JSAMPARRAY buffer;/* Output row buffer */
-
- // rappel :
- // ------
- // typedef unsigned char JSAMPLE;
- // typedef JSAMPLE FAR *JSAMPROW;/* ptr to one image row of pixel samples. */
- // typedef JSAMPROW *JSAMPARRAY;/* ptr to some rows (a 2-D sample array) */
- // typedef JSAMPARRAY *JSAMPIMAGE;/* a 3-D sample array: top index is color */
-
- int row_stride;/* physical row width in output buffer */
-#ifdef GDCM_JPG_DEBUG
- printf("entree dans File::gdcm_read_JPEG_file12, depuis gdcmJpeg\n");
-#endif //GDCM_JPG_DEBUG
-
- /* In this example we want to open the input file before doing anything else,
- * so that the setjmp() error recovery below can assume the file is open.
- * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
- * requires it in order to read binary files.
- */
-
- /* Step 1: allocate and initialize JPEG decompression object */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 1\n");
-#endif //GDCM_JPG_DEBUG
-
- /* We set up the normal JPEG error routines, then override error_exit. */
-
- cinfo.err = jpeg_std_error(&jerr.pub);
- jerr.pub.error_exit = my_error_exit;
-
- /* Establish the setjmp return context for my_error_exit to use. */
- if (setjmp(jerr.setjmp_buffer)) {
- /* If we get here, the JPEG code has signaled an error.
- * We need to clean up the JPEG object, close the input file, and return.
- */
- jpeg_destroy_decompress(&cinfo);
- return(false);
- }
-
- /* Now we can initialize the JPEG decompression object. */
- jpeg_create_decompress(&cinfo);
-
- /* Step 2: specify data source (eg, a file) */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 2\n");
-#endif //GDCM_JPG_DEBUG
- jpeg_stdio_src(&cinfo, fp);
-
- /* Step 3: read file parameters with jpeg_read_header() */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 3\n");
-#endif //GDCM_JPG_DEBUG
- (void) jpeg_read_header(&cinfo, TRUE);
-
- /* We can ignore the return value from jpeg_read_header since
- * (a) suspension is not possible with the stdio data source, and
- * (b) we passed TRUE to reject a tables-only JPEG file as an error.
- * See libjpeg.doc for more info.
- */
-
-#ifdef GDCM_JPG_DEBUG
- printf("--------------Header contents :----------------\n");
- printf("image_width %d image_height %d\n",
- cinfo.image_width , cinfo.image_height);
- printf("bits of precision in image data %d \n",
- cinfo.output_components);
- printf("nb of color components returned %d \n",
- cinfo.data_precision);
-#endif //GDCM_JPG_DEBUG
-
-
- /*
- * JDIMENSION image_width; // input image width
- * JDIMENSION image_height; // input image height
- * int output_components; // # of color components returned
- * J_COLOR_SPACE in_color_space; // colorspace of input image
- * double input_gamma; // image gamma of input image
- * int data_precision; // bits of precision in image data
- */
-
- /* Step 4: set parameters for decompression */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 4\n");
-#endif //GDCM_JPG_DEBUG
-
- /* In this example, we don't need to change any of the defaults set by
- * jpeg_read_header(), so we do nothing here.
- */
-
- /* Step 5: Start decompressor */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 5\n");
-#endif //GDCM_JPG_DEBUG
-
- (void) jpeg_start_decompress(&cinfo);
- /* We can ignore the return value since suspension is not possible
- * with the stdio data source.
- */
-
- /* We may need to do some setup of our own at this point before reading
- * the data. After jpeg_start_decompress() we have the correct scaled
- * output image dimensions available, as well as the output colormap
- * if we asked for color quantization.
- * In this example, we need to make an output work buffer of the right size.
- */
-
- /* JSAMPLEs per row in output buffer */
- row_stride = cinfo.output_width * cinfo.output_components;
-
-#ifdef GDCM_JPG_DEBUG
- printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n",
- cinfo.output_width, cinfo.output_components,row_stride);
-#endif //GDCM_JPG_DEBUG
-
- /* Make a one-row-high sample array that will go away when done with image */
- buffer = (*cinfo.mem->alloc_sarray)
- ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
-
- /* Step 6: while (scan lines remain to be read) */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 6\n");
-#endif //GDCM_JPG_DEBUG
-
- /* jpeg_read_scanlines(...); */
-
- /* Here we use the library's state variable cinfo.output_scanline as the
- * loop counter, so that we don't have to keep track ourselves.
- */
-
-#ifdef GDCM_JPG_DEBUG
- printf ("cinfo.output_height %d cinfo.output_width %d\n",
- cinfo.output_height,cinfo.output_width);
-#endif //GDCM_JPG_DEBUG
-
- pimage=(char *)image_buffer;
-
- while (cinfo.output_scanline < cinfo.output_height) {
- /* jpeg_read_scanlines expects an array of pointers to scanlines.
- * Here the array is only one element long, but you could ask for
- * more than one scanline at a time if that's more convenient.
- */
-
- (void) jpeg_read_scanlines(&cinfo, buffer, 1);
-
- if ( BITS_IN_JSAMPLE == 8) {
- memcpy( pimage, buffer[0],row_stride);
- pimage+=row_stride;
- } else {
- memcpy( pimage, buffer[0],row_stride*2 ); // FIXME : *2 car 16 bits?!?
- pimage+=row_stride*2; // FIXME : *2 car 16 bits?!?
- }
- }
-
- /* Step 7: Finish decompression */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 7\n");
-#endif //GDCM_JPG_DEBUG
- (void) jpeg_finish_decompress(&cinfo);
- /* We can ignore the return value since suspension is not possible
- * with the stdio data source.
- */
-
- /* Step 8: Release JPEG decompression object */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 8\n");
-#endif //GDCM_JPG_DEBUG
-
- /* This is an important step since it will release a good deal of memory. */
- jpeg_destroy_decompress(&cinfo);
-
- /* After finish_decompress, we can close the input file.
- * Here we postpone it until after no more JPEG errors are possible,
- * so as to simplify the setjmp error logic above. (Actually, I don't
- * think that jpeg_destroy can do an error exit, but why assume anything...)
- */
-
- /* At this point you may want to check to see whether any corrupt-data
- * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
- */
-
- /* And we're done! */
-
- return true;
}
-/*
- * SOME FINE POINTS:
- *
- * In the above code, we ignored the return value of jpeg_read_scanlines,
- * which is the number of scanlines actually read. We could get away with
- * this because we asked for only one line at a time and we weren't using
- * a suspending data source. See libjpeg.doc for more info.
- *
- * We cheated a bit by calling alloc_sarray() after jpeg_start_decompress();
- * we should have done it beforehand to ensure that the space would be
- * counted against the JPEG max_memory setting. In some systems the above
- * code would risk an out-of-memory error. However, in general we don't
- * know the output image dimensions before jpeg_start_decompress(), unless we
- * call jpeg_calc_output_dimensions(). See libjpeg.doc for more about this.
- *
- * Scanlines are returned in the same order as they appear in the JPEG file,
- * which is standardly top-to-bottom. If you must emit data bottom-to-top,
- * you can use one of the virtual arrays provided by the JPEG memory manager
- * to invert the data. See wrbmp.c for an example.
- *
- * As with compression, some operating modes may require temporary files.
- * On some systems you may need to set up a signal handler to ensure that
- * temporary files are deleted if the program is interrupted. See libjpeg.doc.
- */
-
-//-----------------------------------------------------------------------------
+#define gdcm_write_JPEG_file gdcm_write_JPEG_file12
+#define gdcm_read_JPEG_file gdcm_read_JPEG_file12
-} // end namespace gdcm
+#include "gdcmJpeg.cxx"
Program: gdcm
Module: $RCSfile: gdcmJpeg8.cxx,v $
Language: C++
- Date: $Date: 2004/10/13 14:15:30 $
- Version: $Revision: 1.7 $
+ Date: $Date: 2004/10/14 22:35:02 $
+ Version: $Revision: 1.8 $
Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
l'Image). All rights reserved. See Doc/License.txt or
=========================================================================*/
#include "gdcmFile.h"
-/*
-DICOM provides a mechanism for supporting the use of JPEG Image Compression
-through the Encapsulated Format (see PS 3.3 of the DICOM Standard).
-Annex A defines a number of Transfer Syntaxes which reference
-the JPEG Standard and provide a number of lossless (bit preserving)
-and lossy compression schemes.
-In order to facilitate interoperability of implementations conforming
-to the DICOM Standard which elect to use one or more
-of the Transfer Syntaxes for JPEG Image Compression, the following policy is specified:
-
- Any implementation which conforms to the DICOM Standard and has elected
- to support any one of the Transfer Syntaxes for lossless JPEG Image Compression,
- shall support the following lossless compression:
- The subset (first-order horizontal prediction [Selection Value 1) of JPEG Process 14
- (DPCM, non-hierarchical with Huffman coding) (see Annex F of the DICOM Standard).
-
- Any implementation which conforms to the DICOM Standard and has elected
- to support any one of the Transfer Syntaxes for 8-bit lossy JPEG Image Compression,
- shall support the JPEG Baseline Compression (coding Process 1).
-
- Any implementation which conforms to the DICOM Standard and has elected
- to support any one of the Transfer Syntaxes for 12-bit lossy JPEG Image Compression,
- shall support the JPEG Compression Process 4.
-
-Note: The DICOM conformance statement shall differentiate between implementations
-that can simply receive JPEG encoded images and those that can receive and process
-JPEG encoded images (see PS 3.2 of the DICOM Standard).
-
-The use of the DICOM Encapsulated Format to support JPEG Compressed Pixel Data
-implies that the Data Elements which are related to the Native Format Pixel Data encoding
-(e.g. Bits Allocated, Bits Stored, High Bit, Pixel Representation, Rows, Columns, etc.)
-shall contain values which are consistent with the characteristics
-of the uncompressed pixel data from which the compressed Data Stream was derived.
-The Pixel Data characteristics included in the JPEG Interchange Format
-shall be used to decode the compressed data stream.
-
-Run Length Encoding Compression
-
-DICOM provides a mechanism for supporting the use of Run Length Encoding (RLE)
-Compression which is a byte oriented lossless compression scheme through
-the encapsulated Format (see PS 3.3 of this Standard).
-Annex G of the DICOM Standard defines RLE Compression and its Transfer Syntax.
-
-Note: The RLE Compression algorithm described in Annex G
-of the DICOM Standard is the compression used in
-the TIFF 6.0 specification known as the "PackBits" scheme.
-
-The use of the DICOM Encapsulated Format to support RLE Compressed Pixel Data
-implies that the Data Elements which are related to the Native Format Pixel Data encoding (
-e.g. Bits Allocated, Bits Stored, High Bit, Pixel Representation, Rows, Columns, etc.)
-shall contain values which are consistent with the characteristics
-of the uncompressed pixel data from which the compressed data is derived
-*/
-
-/*
- * <setjmp.h> is used for the optional error recovery mechanism shown in
- * the second part of the example.
- */
-
-/*
- * Include file for users of JPEG library.
- * You will need to have included system headers that define at least
- * the typedefs FILE and size_t before you can include jpeglib.h.
- * (stdio.h is sufficient on ANSI-conforming systems.)
- * You may also wish to include "jerror.h".
- */
-
extern "C" {
#include "src/jpeg/libijg8/jconfig.h"
#include "src/jpeg/libijg8/jpeglib.h"
-
-#include <setjmp.h>
-}
-
-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:
- */
-
-// FIXME : JPR
-
-//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 (FILE* 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.
- * It's a bit more refined than the above, in that we show:
- * (a) how to modify the JPEG library's standard error-reporting behavior;
- * (b) how to allocate workspace using the library's memory manager.
- *
- * Just to make this example a little different from the first one, we'll
- * assume that we do not intend to put the whole image into an in-memory
- * buffer, but to send it line-by-line someplace else. We need a one-
- * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG
- * memory manager allocate it for us. This approach is actually quite useful
- * because we don't need to remember to deallocate the buffer separately: it
- * will go away automatically when the JPEG object is cleaned up.
- */
-
-/*
- * ERROR HANDLING:
- *
- * The JPEG library's standard error handler (jerror.c) is divided into
- * several "methods" which you can override individually. This lets you
- * adjust the behavior without duplicating a lot of code, which you might
- * have to update with each future release.
- *
- * Our example here shows how to override the "error_exit" method so that
- * control is returned to the library's caller when a fatal error occurs,
- * rather than calling exit() as the standard error_exit method does.
- *
- * We use C's setjmp/longjmp facility to return control. This means that the
- * routine which calls the JPEG library must first execute a setjmp() call to
- * establish the return point. We want the replacement error_exit to do a
- * longjmp(). But we need to make the setjmp buffer accessible to the
- * error_exit routine. To do this, we make a private extension of the
- * standard JPEG error handler object. (If we were using C++, we'd say we
- * were making a subclass of the regular error handler.)
- *
- * Here's the extended error handler struct:
- */
-
-//-----------------------------------------------------------------------------
-struct my_error_mgr {
- struct jpeg_error_mgr pub; /* "public" fields */
- jmp_buf setjmp_buffer; /* for return to caller */
-};
-
-//-----------------------------------------------------------------------------
-typedef struct my_error_mgr* my_error_ptr;
-
-/*
- * Here's the routine that will replace the standard error_exit method:
- */
-METHODDEF(void) my_error_exit (j_common_ptr cinfo) {
- /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
- my_error_ptr myerr = (my_error_ptr) cinfo->err;
-
- /* Always display the message. */
- /* We could postpone this until after returning, if we chose. */
- (*cinfo->err->output_message) (cinfo);
-
- /* Return control to the setjmp point */
- longjmp(myerr->setjmp_buffer, 1);
-}
-
-//-----------------------------------------------------------------------------
-/*
- * Sample routine for JPEG decompression. We assume that the source file name
- * is passed in. We want to return 1 on success, 0 on error.
- */
-
- /**
- * \brief routine for JPEG decompression
- * @param fp pointer to an already open file descriptor
- * 8 significant bits per pixel
- * @param image_buffer to receive uncompressed pixels
- * @return 1 on success, 0 on error
- */
-
-bool gdcm_read_JPEG_file ( FILE* fp, void* image_buffer )
-{
- char* pimage;
-
- /* This struct contains the JPEG decompression parameters and pointers to
- * working space (which is allocated as needed by the JPEG library).
- */
- struct jpeg_decompress_struct cinfo;
-
- /* -------------- inside, we found :
- * JDIMENSION image_width; // input image width
- * JDIMENSION image_height; // input image height
- * int input_components; // nb of color components in input image
- * J_COLOR_SPACE in_color_space; // colorspace of input image
- * double input_gamma; // image gamma of input image
- * -------------- */
-
- /* We use our private extension JPEG error handler.
- * Note that this struct must live as long as the main JPEG parameter
- * struct, to avoid dangling-pointer problems.
- */
- struct my_error_mgr jerr;
- /* More stuff */
-
- JSAMPARRAY buffer;/* Output row buffer */
-
- // rappel :
- // ------
- // typedef unsigned char JSAMPLE;
- // typedef JSAMPLE FAR *JSAMPROW;/* ptr to one image row of pixel samples. */
- // typedef JSAMPROW *JSAMPARRAY;/* ptr to some rows (a 2-D sample array) */
- // typedef JSAMPARRAY *JSAMPIMAGE;/* a 3-D sample array: top index is color */
-
- int row_stride;/* physical row width in output buffer */
-
-#ifdef GDCM_JPG_DEBUG
- printf("entree dans 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);
- 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_stdio_src(&cinfo, fp);
-
- /* Step 3: read file parameters with jpeg_read_header() */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 3\n");
-#endif //GDCM_JPG_DEBUG
-
- (void) jpeg_read_header(&cinfo, TRUE);
-
- /* We can ignore the return value from jpeg_read_header since
- * (a) suspension is not possible with the stdio data source, and
- * (b) we passed TRUE to reject a tables-only JPEG file as an error.
- * See libjpeg.doc for more info.
- */
-
-#ifdef GDCM_JPG_DEBUG
- printf("--------------Header contents :----------------\n");
- printf("image_width %d image_height %d\n",
- cinfo.image_width , cinfo.image_height);
- printf("bits of precision in image data %d \n",
- cinfo.output_components);
- printf("nb of color components returned %d \n",
- cinfo.data_precision);
-#endif //GDCM_JPG_DEBUG
-
-
- /*
- * JDIMENSION image_width; // input image width
- * JDIMENSION image_height; // input image height
- * int output_components; // # of color components returned
- * J_COLOR_SPACE in_color_space; // colorspace of input image
- * double input_gamma; // image gamma of input image
- * int data_precision; // bits of precision in image data
- */
-
- /* Step 4: set parameters for decompression */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 4\n");
-#endif //GDCM_JPG_DEBUG
- /* In this example, we don't need to change any of the defaults set by
- * jpeg_read_header(), so we do nothing here.
- */
-
- /* Step 5: Start decompressor */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 5\n");
-#endif //GDCM_JPG_DEBUG
-
- (void) jpeg_start_decompress(&cinfo);
- /* We can ignore the return value since suspension is not possible
- * with the stdio data source.
- */
-
- /* We may need to do some setup of our own at this point before reading
- * the data. After jpeg_start_decompress() we have the correct scaled
- * output image dimensions available, as well as the output colormap
- * if we asked for color quantization.
- * In this example, we need to make an output work buffer of the right size.
- */
-
- /* JSAMPLEs per row in output buffer */
- row_stride = cinfo.output_width * cinfo.output_components;
-
-#ifdef GDCM_JPG_DEBUG
- printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n",
- cinfo.output_width, cinfo.output_components,row_stride);
-#endif //GDCM_JPG_DEBUG
-
- /* Make a one-row-high sample array that will go away when done with image */
- buffer = (*cinfo.mem->alloc_sarray)
- ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
-
- /* Step 6: while (scan lines remain to be read) */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 6\n");
-#endif //GDCM_JPG_DEBUG
- /* jpeg_read_scanlines(...); */
-
- /* Here we use the library's state variable cinfo.output_scanline as the
- * loop counter, so that we don't have to keep track ourselves.
- */
-#ifdef GDCM_JPG_DEBUG
- printf ("cinfo.output_height %d cinfo.output_width %d\n",
- cinfo.output_height,cinfo.output_width);
-#endif //GDCM_JPG_DEBUG
- pimage=(char *)image_buffer;
-
- while (cinfo.output_scanline < cinfo.output_height)
- {
- /* jpeg_read_scanlines expects an array of pointers to scanlines.
- * Here the array is only one element long, but you could ask for
- * more than one scanline at a time if that's more convenient.
- */
-
- // l'image est deja allouée (et passée en param)
- // on ecrit directement les pixels
- // (on DEVRAIT pouvoir)
-
- (void) jpeg_read_scanlines(&cinfo, buffer, 1);
-
- if ( BITS_IN_JSAMPLE == 8)
- {
- memcpy( pimage, buffer[0],row_stride);
- pimage+=row_stride;
- }
- else
- {
- memcpy( pimage, buffer[0],row_stride*2 ); // FIXME : *2 car 16 bits?!?
- pimage+=row_stride*2; // FIXME : *2 car 16 bits?!?
- }
- }
-
- /* Step 7: Finish decompression */
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 7\n");
-#endif //GDCM_JPG_DEBUG
-
- (void) jpeg_finish_decompress(&cinfo);
-
- /* We can ignore the return value since suspension is not possible
- * with the stdio data source.
- */
-
- /* Step 8: Release JPEG decompression object */
-
-#ifdef GDCM_JPG_DEBUG
- printf("Entree Step 8\n");
-#endif //GDCM_JPG_DEBUG
-
- /* This is an important step since it will release a good deal of memory. */
-
- jpeg_destroy_decompress(&cinfo);
-
- /* After finish_decompress, we can close the input file.
- * Here we postpone it until after no more JPEG errors are possible,
- * so as to simplify the setjmp error logic above. (Actually, I don't
- * think that jpeg_destroy can do an error exit, but why assume anything...)
- */
-
- /* At this point you may want to check to see whether any corrupt-data
- * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
- */
-
- /* And we're done! */
-
- return true;
}
+#define gdcm_write_JPEG_file gdcm_write_JPEG_file8
+#define gdcm_read_JPEG_file gdcm_read_JPEG_file8
-/*
- * SOME FINE POINTS:
- *
- * In the above code, we ignored the return value of jpeg_read_scanlines,
- * which is the number of scanlines actually read. We could get away with
- * this because we asked for only one line at a time and we weren't using
- * a suspending data source. See libjpeg.doc for more info.
- *
- * We cheated a bit by calling alloc_sarray() after jpeg_start_decompress();
- * we should have done it beforehand to ensure that the space would be
- * counted against the JPEG max_memory setting. In some systems the above
- * code would risk an out-of-memory error. However, in general we don't
- * know the output image dimensions before jpeg_start_decompress(), unless we
- * call jpeg_calc_output_dimensions(). See libjpeg.doc for more about this.
- *
- * Scanlines are returned in the same order as they appear in the JPEG file,
- * which is standardly top-to-bottom. If you must emit data bottom-to-top,
- * you can use one of the virtual arrays provided by the JPEG memory manager
- * to invert the data. See wrbmp.c for an example.
- *
- * As with compression, some operating modes may require temporary files.
- * On some systems you may need to set up a signal handler to ensure that
- * temporary files are deleted if the program is interrupted. See libjpeg.doc.
- */
-
-//----------------------------------------------------------------------------
+#include "gdcmJpeg.cxx"
-} // end namespace gdcm
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