Program: gdcm
Module: $RCSfile: gdcmJpeg.cxx,v $
Language: C++
- Date: $Date: 2004/10/14 22:16:33 $
- Version: $Revision: 1.25 $
+ Date: $Date: 2004/12/12 17:21:08 $
+ Version: $Revision: 1.29 $
Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
l'Image). All rights reserved. See Doc/License.txt or
*/
#include <setjmp.h>
+#include <fstream>
+#include "jdatasrc.cxx"
+#include "jdatadst.cxx"
namespace gdcm
{
-
/******************** JPEG COMPRESSION SAMPLE INTERFACE *******************/
/* This half of the example shows how to feed data into the JPEG compressor.
* @return 1 on success, 0 on error
*/
-bool gdcm_write_JPEG_file (FILE* fp, void* im_buf,
+bool gdcm_write_JPEG_file (std::ofstream* fp, void* im_buf,
int image_width, int image_height, int quality)
{
* @return 1 on success, 0 on error
*/
-bool gdcm_read_JPEG_file ( FILE* fp, void* image_buffer )
+bool gdcm_read_JPEG_file ( std::ifstream* fp, void* image_buffer )
{
char* pimage;
*/
/* JSAMPLEs per row in output buffer */
- row_stride = cinfo.output_width * cinfo.output_components;
+ 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",
* 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;
}
-
-printf( "Image size read: %d\n\n\n\n", (cinfo.output_scanline) * rowsize);
/* Step 7: Finish decompression */
#ifdef GDCM_JPG_DEBUG
printf("Entree Step 7\n");
//----------------------------------------------------------------------------
+
+/**
+ * \brief routine for JPEG decompression from a memory buffer.
+ * routine for JPEG decompression from a memory buffer. This routine
+ * only reads one JPEG image at a time, but returns information about
+ * how many bytes have been consumed from the \c input_buffer, and
+ * how many bytes have been written into the output \c image_buffer.
+ *
+ * @param input_buffer pointer to a memory buffer containing the jpeg
+ * compressed data.
+ * @param buflen length of the memory buffer.
+ * @param image_buffer pointer to the location where the decompressed
+ * image will be filled.
+ * @param howManyRead returns how many bytes have been consumed from the
+ * input_buffer.
+ * @param howManyWritten returns how many bytes have been written into
+ * the output image_buffer.
+ * @return 1 on success, 0 on error
+ */
+
+bool gdcm_read_JPEG_memory ( const JOCTET* input_buffer, const size_t buflen,
+ void* image_buffer,
+ size_t *howManyRead, size_t *howManyWritten)
+{
+ 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;
+}
+
} // end namespace gdcm
git://git.creatis.insa-lyon.fr / gdcm.git / blobdiff