haar.cpp

对图片实现haar变换

#include "cv.h"
#include "highgui.h"
#include <math.h>
#include <stdio.h>

/*****************compute log2*******************/
int log2(int x)
{
	int i = 0;
	while(x != 1)
	{
		i++;
		x = x / 2;
	}
	return i;
}

/*****************compute exp2*******************/
int exp2(int x)
{
	int i = 1;
	while(x != 0)
	{
		i = i * 2;
		x--;
	}
	return i;
}

/*****************main function*****************/
void main( int argc, char** argv )
{
	IplImage* src;  //pointer of source image
	IplImage* dst;  //pointer of destination image
	IplImage* sub;  //pointer of subtraction image
	CvSize dst_size;
	CvSize sub_size;

	//load image
	if( argc == 2 && (src = cvLoadImage( argv[1], -1)) != 0 )
	{
	}
	else
	{
		src = cvLoadImage("bike.bmp");
	}
    

	int row = src->height;
	int arr = src->width;
	CvScalar s;
	CvScalar d;
	double grayValue[300][300];   //array that saves gray values
	double temp[300];
	double threshold;
	printf("Choose a threshold: ");
	scanf("%lf", &threshold);
	for(int i = 0; i < row; i++)
	{
		for(int j = 0; j < arr; j++)
		{
			s =cvGet2D(src, i, j);
			grayValue[i][j] = s.val[0];
		}
	}

	int logRow = log2(row);
	if(exp2(logRow) < row)   //complement the rows
	{
		logRow += 1;
		int newRow = exp2(logRow);
		for(i = row; i < newRow; i++)
			for(int j = 0; j < arr; j++)
				grayValue[i][j] = 0;
		row = newRow;
	}

	int logArr = log2(arr);
	if(exp2(logArr) < arr)   //complement the columns
	{
		logArr += 1;
		int newArr = exp2(logArr);
		for(i = 0; i < row; i++)
			for(int j = arr; j < newArr; j++)
				grayValue[i][j] = 0;
		arr = newArr;
	}

	//haar wavelet transform
	//transform on rows
	for(i = 0; i < row; i++)
	{
		int currentArr = arr;
		while(currentArr != 1)
		{
			for(int j = 0; j < currentArr/2; j++)
			{
				temp[j] = (grayValue[i][2*j] + grayValue[i][2*j+1])/2;
                temp[j+currentArr/2] = grayValue[i][2*j] - temp[j];
			}
			for(j = 0; j < currentArr; j++)
			{
				grayValue[i][j] = temp[j];
			}
			currentArr /= 2;
		}
	}

	//transform on rows
    for(int j = 0; j < arr; j++)
	{
		int currentRow = row;
		while(currentRow != 1)
		{
			for(int i = 0; i < currentRow/2; i++)
			{
				temp[i] = (grayValue[2*i][j] + grayValue[2*i+1][j])/2;
                temp[i+currentRow/2] = grayValue[2*i][j] - temp[i];
			}
			for(i = 0; i < currentRow; i++)
			{
				if(fabs(temp[i]) < threshold)   //threshold
					grayValue[i][j] = 0;
				else
					grayValue[i][j] = temp[i];
			}
			currentRow /= 2;
		}
	}

	
	//Decompression
    //on columns
	for(j = 0; j < arr; j++)
	{
		int currentRow = 1;
		double sum = 0;
		while(currentRow != row)
		{
			for(i = 0; i < currentRow; i++)
			{
				sum = grayValue[i][j] * 2;
				temp[2*i] = grayValue[i][j] + grayValue[i+currentRow][j];
				temp[2*i+1] = sum - temp[2*i];
			}
	        for(i = 0; i < currentRow * 2; i++)
				grayValue[i][j] = temp[i];
			currentRow *= 2;
		}
	}

	//on rows
    for(i = 0; i < row; i++)
	{
		int currentArr = 1;
		double sum = 0;
		while(currentArr != arr)
		{
			for(j = 0; j < currentArr; j++)
			{
				sum = grayValue[i][j] * 2;
				temp[2*j] = grayValue[i][j] + grayValue[i][j+currentArr];
				temp[2*j+1] = sum - temp[2*j];
			}
	        for(j = 0; j < currentArr * 2; j++)
				grayValue[i][j] = temp[j];
			currentArr *= 2;
		}
	}

	
	dst_size.width = src->width;
	dst_size.height = src->height;
    dst = cvCreateImage(dst_size, src->depth, src->nChannels);

	sub_size.width = src->width;
	sub_size.height = src->height;
    sub = cvCreateImage(sub_size, src->depth, src->nChannels);
    
	for(i = 0; i < dst_size.height; i ++)
	{
		for(j = 0; j < dst_size.width; j++)
		{
			d.val[0] = grayValue[i][j];
            d.val[1] = grayValue[i][j];
			d.val[2] = grayValue[i][j];
			cvSet2D(dst, i, j, d);
		}
	}

	//show the src_image and the dst_image
	cvNamedWindow("src", 1);
	cvNamedWindow("dst", 1);
	cvShowImage("src", src);
	cvShowImage("dst", dst);
	cvSaveImage("newbike.bmp", dst);

	for(i = 0; i < src->height; i++)
	{
		for(j = 0; j < src->width; j++)
		{
			s = cvGet2D(src, i, j);
			grayValue[i][j] = grayValue[i][j] - s.val[0];
		}
	}

	//sub_image scales
	double x, y;  //scaling coefficients
	double max = grayValue[0][0];
	double min = grayValue[0][0];
	for(i = 0; i < src->height; i++)
		for(j = 0; j < src->width; j++)
		{
			if(grayValue[i][j] > max)
				max = grayValue[i][j];
			else if(grayValue[i][j] < min)
                min = grayValue[i][j];
		}
	if(min < 0)
	{
		x = fabs(min);
		y = x + max;
		for(i = 0; i < src->height; i++)
			for(j = 0; j < dst_size.width; j++)
			{
				grayValue[i][j] = (grayValue[i][j] + x) * 255 / y;
			}
	}

	for(i = 0; i < src->height; i++)
	{
		for(j = 0; j < src->width; j++)
		{
			s.val[0] = grayValue[i][j];
			s.val[1] = grayValue[i][j];
			s.val[2] = grayValue[i][j];
			cvSet2D(sub, i, j, s);
		}
	}
    
    //show the sub_image
	cvNamedWindow("sub", 1);
	cvShowImage("sub", sub);
	cvSaveImage("subbike.bmp", sub);

	cvWaitKey(0);                   //wait for pressing any key
	cvDestroyWindow("src");
	cvDestroyWindow("dst");
	cvDestroyWindow("sub");
	cvReleaseImage(&src );
	cvReleaseImage(&dst);
    cvReleaseImage(&sub);
}