Help me out with this C code for histogram equalization

Discussion in 'C' started by getbiplab, Sep 14, 2008.

  1. getbiplab

    getbiplab New Member

    Joined:
    Sep 8, 2008
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    0
    Code:
    #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,t;
    char *fullname;
    char *fname;
    int hist[256],tmp=0,sum=0;
    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,height,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;
    		//printf("%d\n",rgb1[i][j]);
    		//delay(100);
    		}
    		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;width;j++)
    		{
    			printf("%d\n",rgb1[i][j]);
    			delay(100);
    		}
    	}	
         	for(i=0;i<height;i++)
    	{
    		for(j=0;j<width;j++)
    		{
    			t=rgb1[i][j];
    			//printf("%d\n",t);
    			//delay(100);
    			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);
    			//printf("%d %d\n",t,rgb1[i][j]);
    			//delay(100);	
    		}
    	} 
    	/*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
    
    }
    
    
    In the above code..I have two problems...
    when assining the value of rgb1[][]..thn if i print the values..it is giving correct results..but if i try to print it outside the block..some garbage values are printed..
    and no code is running beyond...
    Code:
    for(i=0;i<height;i++)
    	{
    		for(j=0;j<width;j++)
    		{
    			t=rgb1[i][j];
    			//printf("%d\n",t);
    			//delay(100);
    			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);
    			//printf("%d %d\n",t,rgb1[i][j]);
    			//delay(100);	
    		}
     
    Last edited by a moderator: Sep 14, 2008
  2. hbilling

    hbilling New Member

    Joined:
    Aug 30, 2008
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    0
    Hi,
    I don't think i clearly understand ur issue!. But i see an issue here. You are using(or rather reusing) the variable 'i' in the loop.
    Code:
    for(i=0;i<height;i++)
    	{
    		for(j=0;j<width;j++)
    		{
    			t=rgb1[i][j];
    			//printf("%d\n",t);
    			//delay(100);
    			for(i=0;i<tmp;i++) <<< Here u are using the same variable 'i' as the outer loop.
                                                        // You could use a new variable like 'inner_i' here. I guess thats what u actually intended to..
    			{
    			if(sum_hist[i][0]==t)
    			index=sum_hist[i][1];
    			}
    			index=index-min;
    			rgb1[i][j]=abs(index*255/p);
    			//printf("%d %d\n",t,rgb1[i][j]);
    			//delay(100);	
    		}
     
    Last edited by a moderator: Sep 14, 2008
  3. oogabooga

    oogabooga New Member

    Joined:
    Jan 9, 2008
    Messages:
    115
    Likes Received:
    11
    Trophy Points:
    0
    This is obviously an old (16-bit?) piece of code you are trying to resurrect. Rarely a good idea. You should start fresh or at least find a more modern starting point.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice