Coming up with the histrogram of medical images

[metamofia]

Hi, im doing histogram equalization as my final year project. as for now i need to come up with just the histogram for the image i will be opening. im using mfc and have done a few codes to my project. the recent update was me writing the codes to calculate every pixel's value within the image. so what i want to know now is how do i draw the histogram, ie the values of the intensity corresponding to the total pixel numbers. this is my code below:

//**************************************************************************************//

void CLEO_MedivisionView::OnUpdateToolsHistogram(CCmdUI *pCmdUI)
{
	// TODO: Add your command update UI handler code here
			
	if (fileopen) {
		pCmdUI->Enable(true);
	}
	else {
		pCmdUI->Enable(false);
	}
}
void CLEO_MedivisionView::OnToolsHistogram()
{
	// TODO: Add your command handler code here
	int x_tick, y_tick;
	int j;
	int a_loop, b_loop;
	int k, t, f, i;
	int x, g;
	int q;
	unsigned int intMFC;
	unsigned int intMFC1;
	unsigned int intMFC2;
	unsigned short array1[256];
	char c[10];
	char p[10];
	char l[10];
	CString MFCString;
										//unsigned short array1[65535];
	pDC = GetDC();				    	//OnDraw member function
	hdc = pDC->GetSafeHdc();
	CPen aPen;
	aPen.CreatePen(PS_SOLID, 2, RGB(255, 225, 225));
	CPen* pOldPen = pDC->SelectObject(&aPen);


    pDC->MoveTo(600,400);  //drawing of x-axis
	pDC->LineTo(920,400);
	pDC->MoveTo(920,400);
	pDC->LineTo(915,405);
	pDC->MoveTo(920,400);
	pDC->LineTo(915,395);  //drawing of x-axis
	
	x_tick = 600;		   //declaring constants
	y_tick = 400;

	for(j=1; j<=10; j++)  //control the loop so that it draws ticks every 30 pixels
	{
		pDC->MoveTo(x_tick+(j*30),y_tick-5); 
		pDC->LineTo(x_tick+(j*30),y_tick+5);	
	}
	pDC->MoveTo(600,400);    //drawing of y-axis
	pDC->LineTo(600,80);
	pDC->MoveTo(600,80);
	pDC->LineTo(605,85);
	pDC->MoveTo(600,80);
	pDC->LineTo(595,85);	 //drawing of y-axis

	for(t=1; t<=10; t++)	 //control the loop so that it draws ticks every 30 pixels
	{
		pDC->MoveTo(x_tick-5,y_tick-(t*30)); 
		pDC->LineTo(x_tick+5,y_tick-(t*30));
	}

	intensity= "Intensity";	   //labelling of x-axis
	SetBkColor(hdc, RGB(0, 0, 0));
	SetTextColor(hdc, RGB(255, 255 ,255 ));
	TextOut(hdc, 930, 390, LPCTSTR(intensity), 9);

	pixels = "Pixels";	    //labelling of y-axis
	SetTextColor(hdc, RGB(255, 255 ,255 ));
	TextOut(hdc, 580, 55, LPCTSTR(pixels), 6); 

	numeric = "0";         //number zero (universal)
	SetTextColor(hdc, RGB(95, 158, 160));
	TextOut(hdc, 585, 400, LPCTSTR(numeric),1);

    intMFC = 0;			 //declaring constants
	a_loop = 595;

	for(k=1; k<=5; k++)	 //for every two ticks, draw legend of +52 each time it loops
	{	
		intMFC = intMFC+52;
	    itoa(intMFC,c,10);
	    CString MFCString;
	    MFCString = c;
		if(intMFC<100)	     //if number is XX then just show 2 digits
		{
			test = c;
			SetTextColor(hdc, RGB(95, 158 ,160));
			TextOut(hdc, a_loop+(k*60), 405, LPCTSTR(test), 2);
		}
		else if(intMFC>=100)  //if number is XXX then show 3 digits
		{
			test = c;
			SetTextColor(hdc, RGB(95, 158, 160));
			TextOut(hdc, a_loop+(k*60), 405, LPCTSTR(test), 3);
		}

	}

	intMFC1 = 0;			//declaring of constants
	intMFC2 = 0;
	b_loop = 392;
	
	if (no_of_rows == 256 && no_of_cols == 256)	 // initiate if image its by 256*256
	{
		for(f=1; f<=5; f++)		      // for 5-ticks axis
		{ 
		intMFC1 = (((256 * 256)/5)+0.3) * f;  // calculate each of the 5 marking is +13107
	    itoa(intMFC1,p,10);				  
	    CString MFCString;
	    MFCString = p;

		test1 = p;
		SetTextColor(hdc, RGB(95, 158 ,160));
		TextOut(hdc, 540, b_loop-(f*60), LPCTSTR(test1), 5);	 // type casting
		}   
	}

	else if (no_of_rows == 512 && no_of_cols == 512)  // if image is 512*512 run this
	{
		for(q=1; q<=5; q++)    // for 5-ticks axis		                   
		{   
			intMFC2 = (((512 * 512)/5)+0.8) * q; // to calculate each marking is +52428
			itoa(intMFC2,l,10);			   
		
			MFCString = l;					 
			if(intMFC2<100000)	//'if' statement used because if digit is less
				                //than 100000, it shows crap at the last digit position
			{
				test2 = l;
				SetTextColor(hdc, RGB(95, 158 ,160));
				TextOut(hdc, 540, b_loop-(q*60), LPCTSTR(test2), 5);	
			}
			else if(intMFC2>=100000)	//if digit is more or equal to 100000, do this
			{
				test2 = l;
				SetTextColor(hdc, RGB(95, 158, 160));
				TextOut(hdc, 540, b_loop-(q*60), LPCTSTR(test2),6);
			}
		}
	}


	//count pixel intensity
	if (no_of_rows == 512 && no_of_cols == 512)
	{
	//'for' loop couting from 0 to 255 which simply zeros out each element in array1 to prepare the array to do the count of the bytes in the image
		for (i=0;i<255;i++) 
		{
			array1[i]=0;
		}
	//'for' loop to loop through the bytes of the image
		for (i=0; i<262143; i++)
		{ 
		array1[image[i]]++;
		}
	}

	else if (no_of_rows == 256 && no_of_cols == 256)
	{
		for (g=0;g<255;g++)
		{
			array1[g]=0;
		}

		for (g=0;g<65535; g++)
		{
			array1[image256[g]]++;
		}
	}

}

image[i] is a variable for 512*512 image and image256[i] is for 256*256 image. pls do help me in this thanks! and i will upload the jpeg of what my project looks like as of now so u wont get lost in what im doing.