#include <stdio.h>
  

  #include <stdlib.h>
  

  #include <string.h>
  

  #include <unistd.h>
  

  #include <time.h>
  

  #include <inttypes.h>
  

  

  #include "png.h"
  

  

  #include "pngio.h"
  

  #include "error.h"
  

  #include "image.h"
  

  

  

  /*==============================================================================*
  

  *  read_png                                                                    *
  

  *==============================================================================*/
  

  

  int x, y;
  

  

  int width, height;
  

  

  int channels;
  

  

  png_byte color_type;
  

  png_byte bit_depth;
  

  

  png_structp png_ptr;
  

  png_infop info_ptr;
  

  int number_of_passes;
  

  png_bytep *row_pointers;
  

  

  

  

  png_uint_32 w, h;
  

  size_t npixels;
  

  //png_uint_32* raster;
  

  //png_uint_32
  

  

  

  

  

  int read_png (char * input_filename, picture *thePicture, FILE *status_log)
  

  {
  

  int err = no_err;
  

  

  char header[8];    // 8 is the maximum size that can be checked
  

  

  /* open file and test for it being a png */
  

  FILE *fp = fopen(input_filename, "rb");
  

  if (fp){
  

  

  //abort_("[read_png_file] File %s could not be opened for reading", file_name);
  

  

  fread(header, 1, 8, fp);
  

  

  /* checked out with a proper PNG signature */
  

  if (png_check_sig(header, 8)){
  

  

  /* initialize stuff */
  

  png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
  

  

  if (png_ptr){
  

  

  info_ptr = png_create_info_struct(png_ptr);
  

  if (info_ptr){
  

  

  

  if (setjmp(png_jmpbuf(png_ptr))){
  

  

  fprintf(status_log, "Error during init_io. \n");
  

  

  }else{
  

  

  //takes our file stream pointer(fp) and stores it in the png_ptr struct for later use.
  

  png_init_io(png_ptr, fp);
  

  //lets libpng know that we already checked the 8 signature bytes
  

  png_set_sig_bytes(png_ptr, 8);
  

  

  //information is stored in the information struct
  

  png_read_info(png_ptr, info_ptr);
  

  

  //png_read_update_info(png_ptr, info_ptr);
  

  

  width = png_get_image_width(png_ptr, info_ptr);
  

  height = png_get_image_height(png_ptr, info_ptr);
  

  

  //w = png_get_image_width(png_ptr, info_ptr);
  

  //h = png_get_image_height(png_ptr, info_ptr);
  

  

  fprintf(status_log,"png-image-details: width=%i - height=%i\n",width,height);
  

  

  //npixels = width * height;
  

  npixels = width * height;
  

  

  

  /* Read the whole image into memory at once. */
  

  

  /* read file */
  

  if (setjmp(png_jmpbuf(png_ptr)))
  

  

  fprintf(status_log, "Error during read_image. \n");
  

  

  

  png_uint_32 *raster = malloc(npixels * 4 *sizeof(png_uint_32));
  

  

  //row_pointers = (png_bytep*) malloc(npixels * sizeof(png_bytep));
  

  row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
  

  

  for (y=0; y<height; y++)
  

  row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
  

  

  png_read_image(png_ptr, row_pointers);
  

  

  

  if(raster != NULL){
  

  

  

  channels = png_get_channels(png_ptr, info_ptr);
  

  fprintf(status_log,"Bild-Kanal ist %d .\n", channels);
  

  

  fprintf(status_log,"Bild ist geladen\n");
  

  

  thePicture->pixelmap = row_pointers;
  

  thePicture->width = width;
  

  thePicture->height = height;
  

  thePicture->type = png_type;
  

  

  

  }else{
  

  

  fprintf(status_log,"Memory error.\n");
  

  err = mem_err;
  

  

  }
  

  fclose(fp);
  

  

  }
  

  

  

  }else{
  

  fprintf(status_log, "png_create_info_struct failed. \n");
  

  //err = mem_err;
  

  }
  

  

  }else{
  

  

  fprintf(status_log, "png_create_read_struct failed. \n");
  

  }
  

  

  

  }else{
  

  

  fprintf(status_log, "checking PNG failed. \n");
  

  

  }
  

  

  }else{
  

  

  fprintf(status_log,"Error. Fail to open the png.\n");
  

  err = file_err;
  

  

  }
  

  

  

  return err;
  

  

  }