Program: gdcm
Module: $RCSfile: gdcmFile.h,v $
Language: C++
- Date: $Date: 2004/09/13 07:49:36 $
- Version: $Revision: 1.47 $
+ Date: $Date: 2004/09/17 08:54:26 $
+ Version: $Revision: 1.48 $
Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
l'Image). All rights reserved. See Doc/License.txt or
// For JPEG 8 Bits, body in file gdcmJpeg.cxx
bool gdcm_read_JPEG_file (FILE *fp, void * image_buffer);
- static int gdcm_read_RLE_fragment(char **areaToRead, long lengthToDecode,
- long uncompressedSegmentSize, FILE *fp);
+ bool gdcm_write_JPEG_file (FILE *fp, void * image_buffer,
+ int image_width, int image_heigh,
+ int quality);
// For JPEG 12 Bits, body in file gdcmJpeg12.cxx
bool gdcm_read_JPEG_file12 (FILE *fp, void* image_buffer);
+ bool gdcm_write_JPEG_file12 (FILE *fp, void* image_buffer,
+ int image_width, int image_height,
+ int quality);
// For JPEG 2000, body in file gdcmJpeg2000.cxx
bool gdcm_read_JPEG2000_file (FILE *fp, void* image_buffer);
// For Run Length Encoding
- bool gdcm_read_RLE_file (FILE *fp, void* image_buffer);
-
+ bool gdcm_read_RLE_file (FILE *fp, void* image_buffer);
+// FIXME : *sure* it's NOT static (C++)
+// (would be static in C, or embedded in ADA)
+// It's NOT a method, but a not user intended fonction.
+// How do we write that in C++ ?)
+ static int gdcm_read_RLE_fragment(char **areaToRead, long lengthToDecode,
+ long uncompressedSegmentSize, FILE *fp);
// members variables:
/// \brief Header to use to load the file
#include <setjmp.h>
}
+
+/******************** 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 gdcmFile
+ * \brief routine for JPEG decompression
+ * @param fp pointer to an already open file descriptor
+ * 8 significant bits per pixel
+ * @param image_buffer 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! */
+}
+
+
+
+/*
+ * 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.
int row_stride;/* physical row width in output buffer */
#ifdef GDCM_JPG_DEBUG
- printf("entree dans gdcmFile::gdcm_read_JPEG_file12, depuis gdcmJpeg\n");
+ printf("entree dans gdcmFile::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,
return(true);
}
+
/*
* SOME FINE POINTS:
*
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