-#include "iddcmjpeg.h"
-#include <stdlib.h>
-
-static ClbJpeg* ClbJpegAlloc(void);
-static void ClbJpegInit (ClbJpeg *);
-static int ClbJpegDecodeDiff(ClbJpeg *);
-static BOOL ClbJpegDecodeData(ClbJpeg *);
-static int ClbJpegReadBit(ClbJpeg *);
-static BOOL ClbJpegReadHeader(ClbJpeg *);
-static BOOL ClbJpegStart(ClbJpeg *,FILE *);
-static BOOL ClbJpegFillHuffTable(ClbJpeg *);
-
-
-
-
-void _IdDcmJpegFree(ClbJpeg *jpg)
-{
- free(jpg->DataImg);
- free(jpg);
+// gdcmJpeg.cxx
+//-----------------------------------------------------------------------------
+#include <stdio.h>
+#include "gdcmFile.h"
+
+#define BITS_IN_JSAMPLE 8
+
+/*
+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 "jpeglib.h"
+#include <setjmp.h>
}
-
-ClbJpeg * _IdDcmJpegRead (FILE * fp){
-ClbJpeg * jpg=NULL;
- jpg=ClbJpegAlloc();
- if(!jpg)
- return(NULL);
- ClbJpegInit (jpg);
- if(!ClbJpegStart(jpg, fp))
- return (NULL);
- return (jpg);
+/******************** 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);
}
-
-
-static void ClbJpegInit (ClbJpeg *jpg) {
-int n;
- for (n=0;n<256;n++)
- {
- jpg->lHuffTable[n].HufCode=0;
- jpg->lHuffTable[n].HufSz=0;
- jpg->lHuffTable[n].HufVal=0;
- }
- jpg->ValCurByte=0;
- jpg->PosCurBit=10;
- jpg->MarkerFound=0;
- jpg->RestartInterval=0;
-}
-
-static ClbJpeg *ClbJpegAlloc(void) {
-ClbJpeg * jpg;
- jpg = (ClbJpeg *)malloc(sizeof(ClbJpeg));
- ClbJpegInit(jpg);
-return jpg;
-}
+//-----------------------------------------------------------------------------
+/*
+ * 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 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
+ (void) jpeg_finish_decompress(&cinfo);
+
+ /* We can ignore the return value since suspension is not possible
+ * with the stdio data source.
+ */
-static BOOL ClbJpegFillHuffTable(ClbJpeg *jpg)
-{
- unsigned char c;
- //int testindex=0;
- int n=0;
- int NiDHT=0;
- int indexY=0;
- int k, Code, Si, i;
-
- for (c=0;c<255;c++)
- jpg->RawDHTstart[c]=0;
-
- c=fgetc(jpg->infp);
-
-
- jpg->MaxHuffSz=0;
- jpg->MaxHuffVal=0;
-
- for (n=1;n<17;n++)
- {
- jpg->RawDHT[n]=fgetc(jpg->infp);
- NiDHT+=jpg->RawDHT[n];
- if (jpg->RawDHT[n]!=0)
- jpg->MaxHuffSz=n;
- }
-
- for(n=1;n<16;n++)
- {
- if(jpg->RawDHT[n]>0)
- {
- jpg->RawDHTstart[n]=indexY+1;
- for (i=1;i<(jpg->RawDHT[n]+1);i++)
- {
- indexY+=1;
- c=fgetc(jpg->infp);
- jpg->lHuffTable[indexY].HufVal=c;
- jpg->MaxHuffVal=c;
- jpg->lHuffTable[indexY].HufSz=n;
- }
- }
- }
- k=1;
- Code=0;
-
- Si=jpg->lHuffTable[k].HufSz;
-
- while(1)
- {
- if (k>=NiDHT) break;
- while( Si==jpg->lHuffTable[k].HufSz)
- {
- jpg->lHuffTable[k].HufCode=Code;
- Code+=1;
- k+=1;
- }
- if (k<NiDHT)
- {
- while (jpg->lHuffTable[k].HufSz>Si)
- {
- Code=Code<<1;
- Si+=1;
- }
- }
- }
-
- return 1;
-}
+ /* Step 8: Release JPEG decompression object */
-
+#ifdef GDCM_DEBUG
+ printf("Entree Step 8\n");
+#endif //GDCM_DEBUG
-static BOOL ClbJpegStart(ClbJpeg *jpg, FILE *inputfp)
-{
- jpg->infp=inputfp;
- if (!ClbJpegReadHeader(jpg)) return 0;
- //printf("sortie ClbJpegReadHeader\n");
- if (!ClbJpegDecodeData(jpg)) return 0;
- //printf("sortie ClbJpegDecodeData\n");
- return 1;
-}
+ /* This is an important step since it will release a good deal of memory. */
-static BOOL ClbJpegReadHeader(ClbJpeg *jpg)
-{
- unsigned char gr;
- unsigned char el;
- unsigned char l2;
- unsigned char l1;
- unsigned int sztag;
- long ouca=0;
- BOOL HeaderEnd=0;
- BOOL isLossLess=0;
-
- int tp;
-
- gr=fgetc(jpg->infp); //FF
- el=fgetc(jpg->infp); //D8
-
- while(!HeaderEnd)
- {
- gr=fgetc(jpg->infp);
- if(gr!=0xFF) return 0;
- el=fgetc(jpg->infp);
-
- if ( (el==0xFF) || (el==0x01) || (el==0xD8) ||(el==0xD9) ||( (el>=0xD0) && (el<=0xD7) ))
- ;
- else
- {
- l1=fgetc(jpg->infp);
- l2=fgetc(jpg->infp);
- sztag=(l1*256)+l2-2; //tag lengh
- ouca=ftell(jpg->infp);
-
- if (el==0xC3)
- {
- jpg->lSof.precision=fgetc(jpg->infp);
-
- l1=fgetc(jpg->infp);
- l2=fgetc(jpg->infp);
- jpg->lSof.Himg=(l1*256)+l2;
-
- l1=fgetc(jpg->infp);
- l2=fgetc(jpg->infp);
- jpg->lSof.Wimg=(l1*256)+l2;
-
- jpg->lSof.NbComponent=fgetc(jpg->infp);
-
- jpg->lSof.SofTabPos=ftell(jpg->infp);
-
- isLossLess=1; // TRUE
- }
-
- if (el==0xC4)
- {
- ClbJpegFillHuffTable(jpg);
- }
- if (el==0xDA)
- {
- jpg->lSos.CompCount=fgetc(jpg->infp);
- for (tp=0;tp<jpg->lSos.CompCount;tp++)
- {
- jpg->lSos.CompId=fgetc(jpg->infp);
- jpg->lSos.CompDc=fgetc(jpg->infp);
- }
- jpg->lSos.SpectralSelStart=fgetc(jpg->infp);
- jpg->lSos.SpectralSelEnd=fgetc(jpg->infp);
- jpg->lSos.SuccessiveAp=fgetc(jpg->infp);
- jpg->lSos.Sospttrans=(jpg->lSos.SuccessiveAp & 16);
- HeaderEnd=1;
- }
- if (el==0xDD)
- {
- l1=fgetc(jpg->infp);
- l2=fgetc(jpg->infp);
- jpg->RestartInterval=(l1*256)+l2;
- }
-
- fseek(jpg->infp,(ouca+sztag),0);
- }
- }
-
- if (!isLossLess) return 0;
- return 1;
+ 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...)
+ */
-static int ClbJpegReadBit(ClbJpeg *jpg)
-{
- int r=0;
- unsigned char c;
- if(jpg->PosCurBit>8) // need lire octet suivant
- {
- jpg->ValCurByte=fgetc(jpg->infp);
- if (jpg->ValCurByte==0xFF)
- {
- c=fgetc(jpg->infp);// est 00 ou restart marker: a skiper
- if (c!=0)
- {
- jpg->ValCurByte=fgetc(jpg->infp);
- jpg->PosCurBit=1;
- jpg->MarkerFound=1;
- return 0;
- }
- }
- jpg->PosCurBit=2;
- return (jpg->ValCurByte>>7);
- }
- else
- {
- r=(1&(jpg->ValCurByte>>(8-jpg->PosCurBit)));
- jpg->PosCurBit+=1;
- return r;
- }
-}
+ /* 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! */
-static BOOL ClbJpegDecodeData(ClbJpeg *jpg)
-{
- 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*)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;
+ return(true);
}
-static int ClbJpegDecodeDiff(ClbJpeg *jpg)
-{
- int lInput;
- int lInputBits;
- int lHufVal;
- int lDiff;
- int lI;
- int resultat;
- lHufVal = 666;
- lInput = 0;
- lInputBits = 0;
-
-
- while (1)
- {
- lInputBits+=1;
- lInput=(lInput<<1)+ClbJpegReadBit(jpg);
- if (jpg->RawDHT[lInputBits]!=0)
- {
- for(lI=jpg->RawDHTstart[lInputBits];lI<(jpg->RawDHTstart[lInputBits]+jpg->RawDHT[lInputBits]);lI++)
- {
- if (lInput==jpg->lHuffTable[lI].HufCode)
- lHufVal=jpg->lHuffTable[lI].HufVal;
- }
- }
- if (lInputBits>=jpg->MaxHuffSz)
- lHufVal=jpg->MaxHuffVal;
- if (lHufVal<255) break;
- }
- if (lHufVal==0) resultat= 0;
-
- if ( (lHufVal>0) && (lHufVal<16))
- {
- lDiff=0;
- if( ClbJpegReadBit(jpg)==1)
- {
- for (lI=1;lI<lHufVal;lI++)
- {
- lDiff=(lDiff<<1)+ClbJpegReadBit(jpg);
- }
-
- resultat= (lDiff+(1<<(lHufVal-1)));
- }
- else
- {
- for (lI=1;lI<lHufVal;lI++)
- lDiff=(lDiff<<1)+1-ClbJpegReadBit(jpg);
- resultat= -(lDiff+(1<<(lHufVal-1)));
- }
- }
-
- return resultat;
-
-}
+/*
+ * 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.
+ */
+
+//-----------------------------------------------------------------------------
git://git.creatis.insa-lyon.fr / gdcm.git / blobdiff