I have a minor problem with the following code..it reads a .bmp image
and is supposed to produce another .bmp image which is the result of
histogram equalization of the input image...kindly go through it
1st...and the query follows at the end...
#include <stdio.h>
#include <stdlib.h>
#include <dos.h>
#include <mem.h>
#include <string.h>
#include <conio.h>
#include <fcntl.h>
#include <io.h>
#include <math.h>
unsigned char r[360],mini,mode;
unsigned char rgb[256][3],rgb2[256][3],**rgb1;
char *fullname;
char *fname;
int hist[256],tmp=0,sum=0,t;
unsigned int screen_width=320;
unsigned int first_row=0,first_column=0,last_row=0,last_column= 0;
int handle,i,j,rem,color_bits;
long int
file_size,data_offset,size_info_header,width,heigh t,compression,
image_size,xpelspermeter,ypelspermeter,colorsused, k,colorsimpt,p,index,max,min,**sum_hist;
float theta,temp;
void drawdot(int x, int y, int pal_index){
_AX=pal_index;
_CX=x;
_DX=y;
_AH=0x0c;
_BH=0x00;
geninterrupt(0x10);
}
void main(){
gets(fname);
strcpy(fullname,fname);strcat(fullname,".bmp");
handle=_open(fullname,O_RDONLY);if (handle==-1) exit(EXIT_FAILURE);
_read(handle,r,2);if (r[0] !='B' | r[1] !='M') exit(EXIT_FAILURE);
_read(handle,r,
4);file_size=r[0]+0x100*r[1]+0x10000*r[2]+0x1000000*r[3];
_read(handle,r,2);_read(handle,r,2);
_read(handle,r,
4);data_offset=r[0]+256*r[1]+65536*r[2]+0x1000000*r[3];
_read(handle,r,
4);size_info_header=r[0]+256*r[1]+65536*r[2]+0x1000000*r[3];
if (size_info_header !=40) exit(EXIT_FAILURE);
_read(handle,r,4);width=r[0]+0x100*r[1]+0x10000*r[2]+0x1000000*r[3];
if (width screen_width) exit(0);
_read(handle,r,4);height=r[0]+0x100*r[1]+0x10000*r[2]+0x1000000*r[3];
_read(handle,r,2);if (r[0] != 1) exit(EXIT_FAILURE);
_read(handle,r,2);
color_bits=r[0];
_read(handle,r,4);
compression=r[0]+0x100*r[1]+0x10000*r[2]+0x1000000*r[3];
_read(handle,r,4);
image_size=r[0]+256*r[1]+256*256*r[2]+256*256*256*r[3];
_read(handle,r,4);
xpelspermeter=r[0]+0x100*r[1]+0x10000*r[2]+0x1000000*r[3];
_read(handle,r,4);
ypelspermeter=r[0]+0x100*r[1]+0x10000*r[2]+0x1000000*r[3];
_read(handle,r,4);
colorsused=r[0]+0x100*r[1]+0x10000*r[2]+0x1000000*r[3];
_read(handle,r,4);
colorsimpt=r[0]+0x100*r[1]+0x10000*r[2]+0x1000000*r[3];
_AX=0x1201;_BL=0x33;geninterrupt(0x10);//don't add RGB
_AX=0x0013;geninterrupt(0x10);//set mode 13 i.e. 320x200x256
for (i=0;i<256;i++) {
_read(handle,r,4);
rgb[i][0]=r[2]>>2;rgb[i][1]=r[1]>>2;rgb[i][2]=r[0]>>2;
}
rgb1=calloc(height,sizeof(char*));
for(i=0;i<height;i++)
rgb1[i]=calloc(width,sizeof(char));
for (i=0;i<256;i++) {
rgb2[i][0]=i;rgb2[i][1]=i;rgb2[i][2]=i;
}
_ES=FP_SEG(rgb2);_DX=FP_OFF(rgb2);
_BX=0;_CX=0x100; _AX=0x1012;
geninterrupt(0x10);//set DAC from rgb
first_column=(screen_width-width)/2;
last_row=first_row+height-1;last_column=first_column+width-1;
rem=4 - (width % 4);
for (i=0;i<=height-1;i++) {
_read(handle,r,width);
for (j=0;j<=width-1;j++)
{
//drawdot(first_column+j,last_row-i,r[j]);
rgb1[i][j]=(rgb2[r[j]][0]+rgb2[r[j]][1]+rgb2[r[j]][2])/3;
}
if (rem==1) _read(handle,r,1);
else if (rem==2) _read(handle,r,2);
else if (rem==3) _read(handle,r,3);//getch();
}
for(i=0;i<256;i++)
{
hist[i]=0;
}
for(i=0;i<height;i++)
{
for(j=0;j<width;j++)
{
k=(long int)rgb1[i][j];
hist[k]=hist[k]+1;
}
}
for(i=0;i<256;i++)
{
if(hist[i]!=0)
tmp++;
else continue;
}
sum_hist=(long int **)calloc(tmp,sizeof(long int*));
for(i=0;i<tmp;i++)
sum_hist[i]=(long int *)calloc(2,sizeof(long int));
for(i=0;i<256;i++)
{
if(hist[i]!=0)
{
sum_hist[sum][0]=(long int)i;
sum_hist[sum][1]=(long int)hist[i];
sum++;
}
else continue;
}
for(i=1;i<tmp;i++)
sum_hist[i][1]+=sum_hist[i-1][1];
min=sum_hist[0][1];
max=sum_hist[0][1];
for(i=1;i<tmp;i++)
{
if(min>sum_hist[i][1])
min=sum_hist[i][1];
else continue;
}
for(i=1;i<tmp;i++)
{
if(max<sum_hist[i][1])
max=sum_hist[i][1];
else continue;
}
p=((height*width)-min);
for(i=0;i<height;i++)
{
for(j=0;j<widthj++)
{
t=(int)rgb1[i][j];
for(i=0;i<tmp;i++)
{
if(sum_hist[i][0]==t)
index=sum_hist[i][1];
}
index=index-min;
rgb1[i][j]=abs(index*255/p);
//drawdot(first_column+j,last_row-i,rgb1[i][j]);
}
}
/*for(i=0;i<height;i++)
{
for(j=0;j<width;j++)
drawdot(first_column+j,last_row-i,rgb1[i][j]);
}*/
_close(handle);
getch();
_AX=0x1201;_BL=0x33;geninterrupt(0x10);//don't add RGB
_AX=0x0003;geninterrupt(0x10);//set mode 3 i.e. 16-color text
}
tillthis following segment..
for(i=0;i<height;i++)
{
for(j=0;j<widthj++)
{
t=(int)rgb1[i][j];
for(i=0;i<tmp;i++)
{
if(sum_hist[i][0]==t)
index=sum_hist[i][1];
}
index=index-min;
rgb1[i][j]=abs(index*255/p);
//drawdot(first_column+j,last_row-i,rgb1[i][j]);
}
everything is going well...but nothing is being done as soon as the
for loops end...therefore I cant print the output image..What is the
remedy???
