image.cpp

常用算法与数据结构原代码

// label image components

#include <iostream.h>
#include "lqueue.h"
#include "make2d.h"

class Position 
{
	friend void InputImage();
	friend void OutputImage();
	friend void Label();
private:
	int row, col;
};

// globals
int **pixel, m;

void InputImage()
{
	cout << "Enter image size" << endl;
	cin >> m;
	Make2DArray(pixel,m+2,m+2);
	for (int i=1; i<=m; i++)
		for (int j=1; j<=m; j++) 
			cin >> pixel[i][j];
}

void Label()
{// Label image components.
	
	// initialize wall of 0 pixels
	for (int i = 0; i <= m+1; i++) 
	{
		pixel[0][i] = pixel[m+1][i] = 0; // bottom & top
		pixel[i][0] = pixel[i][m+1] = 0; // left & right
	}
	
	// initialize offsets
	Position offset[4];
	offset[0].row = 0; offset[0].col = 1; // right
	offset[1].row = 1; offset[1].col = 0; // down
	offset[2].row = 0; offset[2].col = -1; // left
	offset[3].row = -1; offset[3].col = 0; // up
	
	int NumOfNbrs = 4; // neighbors of a pixel position
	LinkedQueue<Position> Q;
	int id = 1;  // component id
	Position here, nbr;
	
	// scan all pixels labeling components
	for (int r = 1; r <= m; r++)  // row r of image
	{
		for (int c = 1; c <= m; c++)   // column c
		{
			if (pixel[r][c] == 1) 
			{
				// new component}
				pixel[r][c] = ++id; // get next id
				here.row = r; here.col = c;
				
				do 
				{// find rest of component
					for (int i = 0; i < NumOfNbrs; i++) 
					{
						// check all neighbors of here
						nbr.row = here.row + offset[i].row;
						nbr.col = here.col + offset[i].col;
						if (pixel[nbr.row][nbr.col] == 1) 
						{
							pixel[nbr.row][nbr.col] = id;
							Q.Add(nbr);
						}
					} // end of if and for
					
					// any unexplored pixels in component?
					if (Q.IsEmpty()) 
						break;
					Q.Delete(here); // a component pixel
				} 
				while(true);
			} // end of if, for c, and for r
		}
	}
}

void OutputImage()
{// Output labeled image.
	int i, j;
	for (i=1; i <= m; i++) 
	{
		for (j=1; j <= m; j++) 
			cout << pixel[i][j];
		cout << endl;
	}
}

void main(void)
{
	InputImage();
	cout << "The input image is" << endl;
	OutputImage();
	Label();
	cout << "The labeled image is" << endl;
	OutputImage();
}