+ /**
+ * \ingroup gdcmFile
+ * \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 gdcmFile::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_DEBUG
+ printf("entree dans gdcmFile::gdcm_read_JPEG_file12, depuis gdcmJpeg\n");
+#endif //GDCM_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_DEBUG
+ printf("Entree Step 1\n");
+#endif //GDCM_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_DEBUG
+ printf("Entree Step 2\n");
+#endif //GDCM_DEBUG
+
+ jpeg_stdio_src(&cinfo, fp);
+
+ /* Step 3: read file parameters with jpeg_read_header() */
+#ifdef GDCM_DEBUG
+ printf("Entree Step 3\n");
+#endif //GDCM_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_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_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_DEBUG
+ printf("Entree Step 4\n");
+#endif //GDCM_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_DEBUG
+ printf("Entree Step 5\n");
+#endif //GDCM_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_DEBUG
+ printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n",
+ cinfo.output_width, cinfo.output_components,row_stride);
+#endif //GDCM_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_DEBUG
+ printf("Entree Step 6\n");
+#endif //GDCM_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_DEBUG
+ printf ("cinfo.output_height %d cinfo.output_width %d\n",
+ cinfo.output_height,cinfo.output_width);
+#endif //GDCM_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, pimage, 1);
+
+ (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_DEBUG
+ printf("Entree Step 7\n");
+#endif //GDCM_DEBUG