[c-prog] BITMAP...

[s_rafib4u]

Hi,
   Here i am sending the code for scaling the image and saving the 
scaled image into another file .I think till scaling is fine and 
after that the problem occurs can u please find me the solution how 
to save the scaled image..

hoping for a sooner reply..


#include <stdio.h>
#include <stdlib.h>
#include <dos.h>
#include <mem.h>


/* the structure for a bitmap. */
typedef struct bitmap            
{
  int width;
  int height;
  char *data;
} bit_map;



void load_bmp(char *file,bit_map *b);
void scale(bit_map *source, bit_map *dest);
void putimage(bit_map *r, unsigned char * Buffer);




void main()
{
  int i,x,y;
  struct bitmap ibmp;
  struct bitmap obmp={640,480};
  
  load_bmp("cus3.bmp",&ibmp);

  printf("\n\n in function main\n");

  printf("\n\n i am in line %d",__LINE__);

  scale(&ibmp,&obmp);
  
}



void load_bmp(char *file,bit_map *b)
{
  FILE *fp;
  long index;
  int num_colors;
  int x,i;
  if ((fp = fopen(file,"rb")) == NULL)
  {
                printf("Error opening file %s.\n",file);
                exit(1);
        }

  fseek(fp, 18, SEEK_SET);
  fread(&b->width, sizeof(int), 1, fp);
  fseek(fp, 22, SEEK_SET);
  fread(&b->height,sizeof(int), 1, fp);
  fseek(fp, 46, SEEK_SET);
  fread(&num_colors,sizeof(int), 1, fp);

//  assume we are working with an 8-bit file 
  if (num_colors==0)
  num_colors=256;

    //  allocating memory 
  if ((b->data = (char *) malloc((int)(b->width*b->height))) == NULL)
  {
    fclose(fp);
    printf("Error allocating memory for file %s.\n",file);
    exit(1);
  }

   // read the bitmap 

  for(index=(b->height-1)*b->width;index>=0;index-=b->width)
  {
    for(x=0;x<b->width;x++)
        {
      b->data[(int)index+x]=(char)fgetc(fp);
        }
  }
  fclose(fp);
  
 }



void scale(bit_map *source,bit_map *dest)
{
   unsigned char *Image, *screen, *PtrScreen;

   float XRatio, YRatio, X, Y;

   int Xc, Yc;

   int outwidth, outheight;

   int inwidth, inheight;


   int *XPoints, *YPoints, Offset;

   inwidth = source->width + 1;
   inheight = source->height + 1;

   outwidth  = dest->width+1;
   outheight = dest->height+1;

        Image = (unsigned char *)malloc((source->width)*(source-
>height))
    screen = (unsigned char *)malloc((dest->width)*(dest->height))

     XRatio = (float) ((float)inwidth /(float)outwidth );
     YRatio = (float) ((float)inheight /(float)outheight );

   
if((XPoints = (int *)malloc(outwidth * sizeof(int)))==NULL)
        printf("\n malloc fails for xpoints");

   for( Xc=0, X = 0 ; Xc < outwidth ; X+=XRatio, Xc++ )
      XPoints[Xc] = X;

   // for the y axis
if((  YPoints = (int *)malloc(outheight * sizeof(int)))==NULL)
        printf("\n malloc fails for ypoints");

   for( Yc=0, Y = 0 ; Yc < outheight ; Y+=YRatio, Yc++ )
       YPoints[Yc] = Y;

   //use a pointer to run through the array
   PtrScreen = screen;


   for( Yc = 0 ; Yc < outheight ; Yc++ )
   {
      Offset = YPoints[Yc] * inwidth;
      for( Xc = 0 ; Xc < outwidth ; Xc++)
           *PtrScreen++ = dest->data[Offset + XPoints[Xc]];
   }

//put the result in the file
 putimage(dest,screen);

   //free up the allocated memory
   free(screen);
   free(Image);
   free(YPoints);
   free(XPoints);
}
*/

void putimage(bit_map *r, unsigned char * Buffer)
{
        FILE *fp;
   int y, Width;
   unsigned char *Ptr = Buffer;

   Width = r->width;
   fp=fopen("output.bmp","w+");
   for(y =0 ;  y <= r->height ; y++, Ptr+=Width)
      memcpy(fp, Ptr, Width);
}