- int iX,iY;
- int lbInc=0;
- unsigned int mask;
-
- int lPredicted=(1<<(jpg->lSof.precision-1-jpg->lSos.Sospttrans));
-
- jpg->ValCurByte=jpg->lSos.SuccessiveAp;
- jpg->PosCurBit=9;
-
- if (jpg->lSof.precision==8)
- mask=0xFF;
- if (jpg->lSof.precision==12)
- mask=0xFFF;
- if (jpg->lSof.precision==16)
- mask=0xFFFF;
-
- jpg->DataImg=(int*)g_malloc(jpg->lSof.Himg*jpg->lSof.Wimg*sizeof(*jpg->DataImg));
- memset( jpg->DataImg,0,(jpg->lSof.Himg*jpg->lSof.Wimg*sizeof(*jpg->DataImg)));
-
- if (!jpg->RestartInterval)
- {
- for(iX=0;iX<jpg->lSof.Wimg;iX++) // lit première ligne
- {
- lbInc+=1;
- if (lbInc>1)
- lPredicted= jpg->DataImg[lbInc-1];
- jpg->DataImg[lbInc]=lPredicted+ClbJpegDecodeDiff(jpg);
-
- if ( jpg->DataImg[lbInc] > ((1<<(jpg->lSof.precision))-1) )
- jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask;
- if ( jpg->DataImg[lbInc]<0)
- jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask;
- }
-
- for (iY=1;iY<jpg->lSof.Himg;iY++) //lit la suite
- {
- lbInc+=1;
- if (lbInc>(jpg->lSof.Himg*jpg->lSof.Wimg-1)) break;
- lPredicted= jpg->DataImg[lbInc-jpg->lSof.Wimg]; // se base % premier é ligne d'avant
- jpg->DataImg[lbInc]=lPredicted+ClbJpegDecodeDiff(jpg);
-
- if ( jpg->DataImg[lbInc] > ((1<<(jpg->lSof.precision))-1) )
- jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask;
- if ( jpg->DataImg[lbInc]<0)
- jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask;
-
- for(iX=1;iX<jpg->lSof.Wimg;iX++)
- {
- lbInc+=1;
- if (lbInc>(jpg->lSof.Himg*jpg->lSof.Wimg-1)) break;
- if (jpg->lSos.SpectralSelStart==7) // si spectral
- lPredicted=( jpg->DataImg[lbInc-1]+ jpg->DataImg[lbInc-jpg->lSof.Wimg])>>1;
- else
- lPredicted= jpg->DataImg[lbInc-1]; // se base%pixel juste avant
- jpg->DataImg[lbInc]=lPredicted+ClbJpegDecodeDiff(jpg);
-
- if ( jpg->DataImg[lbInc] > ((1<<(jpg->lSof.precision))-1) )
- jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask;
- if ( jpg->DataImg[lbInc]<0)
- jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask;
-
- }
- }
- }
- else // il y a un define interval
- {
- while(1)
- {
- jpg->MarkerFound=0;
- lPredicted=(1<<(jpg->lSof.precision - 1 - jpg->lSos.Sospttrans));
- for (iY=0;iY<jpg->RestartInterval;iY++)
- {
- jpg->DataImg[lbInc]=lPredicted+ClbJpegDecodeDiff(jpg);
-
- if ( jpg->DataImg[lbInc] > ((1<<(jpg->lSof.precision))-1) )
- jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask;
- if ( jpg->DataImg[lbInc]<0)
- jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask;
-
- lbInc+=1;
- if (lbInc>(jpg->lSof.Himg*jpg->lSof.Wimg-1)) return 1;
-
- if (jpg->lSos.SpectralSelStart==7) // si spectral
- lPredicted=( jpg->DataImg[lbInc-1]+ jpg->DataImg[lbInc-jpg->lSof.Wimg])>>1;
- else
- lPredicted= jpg->DataImg[lbInc-1];
- }
- while (!jpg->MarkerFound)
- {
- ClbJpegReadBit(jpg); // skip bits restant avant restart marker
- }
- }
- }
- return 1;
+ char* pimage=(char *)image_buffer;
+ JOCTET* input = (JOCTET*) input_buffer;
+
+ /* 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);
+
+ *howManyRead += input - input_buffer;
+ *howManyWritten += pimage - (char *)image_buffer;
+ 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_memory_src(&cinfo, input, buflen);
+
+ /* 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.
+ */
+
+ // prevent the library from performing any color space conversion
+ if( cinfo.process == JPROC_LOSSLESS )
+ {
+ cinfo.jpeg_color_space = JCS_UNKNOWN;
+ cinfo.out_color_space = JCS_UNKNOWN;
+ }
+
+#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*2;
+
+#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
+
+ int bufsize = cinfo.output_width * cinfo.output_components;
+ size_t rowsize = bufsize * sizeof(JSAMPLE);
+
+ 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.
+ */
+
+ //printf( "scanlines: %d\n",cinfo.output_scanline);
+ (void) jpeg_read_scanlines(&cinfo, buffer, 1);
+ memcpy( pimage, *buffer,rowsize);
+ pimage+=rowsize;
+ }
+
+ /* Step 7: Finish decompression */
+#ifdef GDCM_JPG_DEBUG
+ printf("Entree Step 7\n");
+#endif //GDCM_JPG_DEBUG
+
+ input = (JOCTET *)cinfo.src->next_input_byte;
+
+ (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! */
+ *howManyRead += input - input_buffer;
+ *howManyWritten += pimage - (char *)image_buffer;
+
+ return true;