Matrix for bitmap

[nash83]

Hello.I am just starting to use c++ and I have already some difficulties.I am working with intel c++ compiler 7.I would like to load a bmp image on a matrix.I only can open and read its BITMAPINFOHEADER.How can I load values opend image on a matrix?This is what I have produced"

#include <stdio.h>
#include <math.h>
#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
 
#define WIDTHBYTES(bits)    ((((bits) + 31) >> 5) << 2)
 
void load_bitmap(char *,int,int,void *);
 
void main(int argc, char *argv[])
{
    int i=0,j=0;
    int w=0,h=0,z=0,t=0;
    int altezza,profondita;
    void *buf;
    char *name = "polyhedron8.bmp";
//    FILE *in;
 
//    in=fopen("C:\Program Files\Microsoft Visual Studio\VC98\Include\polyhedron2","r");
 
//    name = in;
//    printf("il valore in cui e memorizzata l`immagine vale %d \n",in);  
    printf("koko de\n");
    load_bitmap(name,w,h,&buf);
    printf("oaru\n");
 
}
 
 
void load_bitmap(char* filename,int width, int height, void* buffer)
{
    BITMAPFILEHEADER    bfh;
    BITMAPINFOHEADER    bih;
    FILE*                fp;
    int                    widthbytes = WIDTHBYTES(width * 24);
    int                 i=0,z=0,t=0;
    int                 tot=0;
 
 
    if((fp = fopen(filename, "rb")) == NULL)
    {
        printf("Cannot open");
        return;
    }
    fread(&bfh,sizeof(BITMAPFILEHEADER), 1, fp);
    fread(&bih,sizeof(BITMAPINFOHEADER), 1, fp);
 
    fread(buffer, sizeof(BYTE), widthbytes * height, fp);
 
}
 

is there anyone who can help me?

[Savage]

Hello.I am just starting to use c++ and I have already some difficulties.I am working with intel c++ compiler 7.I would like to load a bmp image on a matrix.I only can open and read its BITMAPINFOHEADER.How can I load values opend image on a matrix?This is what I have produced"

#include <stdio.h>
#include <math.h>
#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
 
#define WIDTHBYTES(bits)    ((((bits) + 31) >> 5) << 2)
 
void load_bitmap(char *,int,int,void *);
 
void main(int argc, char *argv[])
{
    int i=0,j=0;
    int w=0,h=0,z=0,t=0;
    int altezza,profondita;
    void *buf;
    char *name = "polyhedron8.bmp";
//    FILE *in;
 
//    in=fopen("C:\Program Files\Microsoft Visual Studio\VC98\Include\polyhedron2","r");
 
//    name = in;
//    printf("il valore in cui e memorizzata l`immagine vale %d \n",in);  
    printf("koko de\n");
    load_bitmap(name,w,h,&buf);
    printf("oaru\n");
 
}
 
 
void load_bitmap(char* filename,int width, int height, void* buffer)
{
    BITMAPFILEHEADER    bfh;
    BITMAPINFOHEADER    bih;
    FILE*                fp;
    int                    widthbytes = WIDTHBYTES(width * 24);
    int                 i=0,z=0,t=0;
    int                 tot=0;
 
 
    if((fp = fopen(filename, "rb")) == NULL)
    {
        printf("Cannot open");
        return;
    }
    fread(&bfh,sizeof(BITMAPFILEHEADER), 1, fp);
    fread(&bih,sizeof(BITMAPINFOHEADER), 1, fp);
 
    fread(buffer, sizeof(BYTE), widthbytes * height, fp);
 
}
 

is there anyone who can help me?

You said that you are using C++,right?

Then why don't you use file streams?

Now to the real problem,you are not reading those valuse yet.You need to skip few bytes to read width,height...

Take a look at this pseudo-code:

If open Bitmap file
  Read two bytes (type) and if different than 0x4D42 stop
  Ignore eight bytes
  Read four bytes (start of image data)
  Ignore four bytes
  Read four bytes (width of bitmap)
  Read four bytes (height of bitmap)
  Ignore two bytes
  Read two bytes (bit count of bitmap) and if different than 24 stop
  Read four bytes (compression of bitmap) and if different than BI_RGB stop
  Move to start of image data
  Allocate memory for image data (3(one byte for red, other for
  green other for blue) * ImageWidth * ImageHeight)
  Read (3 * ImageWidth * ImageHeight) bytes from file to buffer
  Swap the red and blue components of buffer
  If ImageHeight is negative
    Flip the buffer lines
End if
Close file

Note:This is for reading uncompressed bitmaps only!
Savage