- /* 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);
-}