對圖像進行哈爾變換

Question

我需要一些幫助，哈爾變換，我必須應用它的圖像。 我的數學不好，我的英語不是那麼棒，我覺得很難從互聯網上的文章中理解。我發現這個頁面http://www.cs.ucf.edu/~mali/haar/haar.cpp其中哈爾變換應用於二維矩陣。我想如果我在那裏給圖像像素矩陣，它應該工作？ 我對這個東西感到困惑，請問有人能讓我有點開心嗎？ 謝謝！

Answer 1

您指向的URL末尾有一個示例。 查看main（）函數。

• 二維變體採用浮法**和兩個參數，高度和寬度
• 浮子**點灰度級的像素的行
• 每一行是一個浮子*，一個指針到第一像素在行
• 每個浮點值是示例代碼中的像素
• 的強度值，尺寸是4x4。

這是其中存儲器分配：

float **mat = new float*[4]; 
for(int m=0;m<4;m++) 
    mat[m] = new float[4]; 

這是其中像素值被設置：

mat[0][0] = 5; mat[0][1] = 6; mat[0][2] = 1; mat[0][3] = 2; 
mat[1][0] = 4; mat[1][1] = 2; mat[1][2] = 5; mat[1][3] = 5; 
mat[2][0] = 3; mat[2][1] = 1; mat[2][2] = 7; mat[2][3] = 1; 
mat[3][0] = 6; mat[3][1] = 3; mat[3][2] = 5; mat[3][3] = 1; 

這就是haar2函數被調用：

haar2(mat,4,4); 

您所需要做的就是根據func的需要提供數據（float **）具有正確的尺寸。您可能希望將結果存儲到可在圖像查看應用程序中打開的輸出文件。

查找PGM格式以獲得真正簡單的解決方案。請注意，haar函數的結果會爲您提供浮點值，您可能必須將它壓縮到8位才能查看圖像。

Answer 2

如果你想使用哈爾特徵做目標檢測，要看看的OpenCV： http://opencv.willowgarage.com/documentation/cpp/object_detection.html

Answer 3

#include<stdio.h> 
#include<stdlib.h> 
#include<math.h> 

typedef struct { 
unsigned char red,green,blue; 
} PPMPixel; 

typedef struct { 
int x, y; 
PPMPixel *data; 
} PPMImage; 

#define CREATOR "SUDIPTAARNAB" 
#define RGB_COMPONENT_COLOR 255 

static PPMImage *readPPM(const char *filename) 
{ 
    char buff[16]; 
    PPMImage *img; 
    FILE *fp; 
    int c, rgb_comp_color; 
    //open PPM file for reading 
    fp = fopen(filename, "rb"); 
    if (!fp) { 
      fprintf(stderr, "Unable to open file '%s'\n", filename); 
      exit(1); 
    } 

    //read image format 
    if (!fgets(buff, sizeof(buff), fp)) { 
      perror(filename); 
      exit(1); 
    } 

//check the image format 
if (buff[0] != 'P' || buff[1] != '6') { 
    fprintf(stderr, "Invalid image format (must be 'P6')\n"); 
    exit(1); 
} 

//alloc memory form image 
img = (PPMImage *)malloc(sizeof(PPMImage)); 
if (!img) { 
    fprintf(stderr, "Unable to allocate memory\n"); 
    exit(1); 
} 

//check for comments 
c = getc(fp); 
while (c == '#') { 
while (getc(fp) != '\n') ; 
    c = getc(fp); 
} 

ungetc(c, fp); 
//read image size information 
if (fscanf(fp, "%d %d", &img->x, &img->y) != 2) { 
    fprintf(stderr, "Invalid image size (error loading '%s')\n", filename); 
    exit(1); 
} 

//read rgb component 
if (fscanf(fp, "%d", &rgb_comp_color) != 1) { 
    fprintf(stderr, "Invalid rgb component (error loading '%s')\n", filename); 
    exit(1); 
} 

//check rgb component depth 
if (rgb_comp_color!= RGB_COMPONENT_COLOR) { 
    fprintf(stderr, "'%s' does not have 8-bits components\n", filename); 
    exit(1); 
} 

while (fgetc(fp) != '\n') ; 
//memory allocation for pixel data 
img->data = (PPMPixel*)malloc(img->x * img->y * sizeof(PPMPixel)); 

if (!img) { 
    fprintf(stderr, "Unable to allocate memory\n"); 
    exit(1); 
} 

//read pixel data from file 
if (fread(img->data, 3 * img->x, img->y, fp) != img->y) { 
    fprintf(stderr, "Error loading image '%s'\n", filename); 
    exit(1); 
} 

fclose(fp); 
return img; 
} 
void writePPM(const char *filename, PPMImage *img) 
{ 
FILE *fp; 
//open file for output 
fp = fopen(filename, "wb"); 
if (!fp) { 
    fprintf(stderr, "Unable to open file '%s'\n", filename); 
    exit(1); 
} 

//write the header file 
//image format 
fprintf(fp, "P6\n"); 

//comments 
fprintf(fp, "# Created by %s\n",CREATOR); 

//image size 
fprintf(fp, "%d %d\n",img->x,img->y); 

// rgb component depth 
fprintf(fp, "%d\n",RGB_COMPONENT_COLOR); 

// pixel data 
fwrite(img->data, 3 * img->x, img->y, fp); 
fclose(fp); 
} 

void imageDivide(const char *filename,PPMImage *img) 
{ 
FILE *fp = fopen(filename,"rb"); 
FILE *filePtr; 
filePtr = fopen ("floatArray.txt","w"); 
int width = 288; 
int height = 352; 
int i,j,m,k,l,i1,j1,l1,n1; 
int *sum; 
float *mean,*var; 
unsigned char buff[(288*352)]; 
unsigned char image[288][352]; 
size_t n = fread(buff, sizeof(buff[0]), sizeof(buff), fp); 
fclose(fp); 
for(i =0; i < height; i++) 
{ 
for(j = 0; j < width;j++) 
{ 
    image[j][i] = buff[(i*width)+j]; 
} 
} 
unsigned char dividedimage[(288*352)/(8*8)][8][8]; 
mean=(float *)malloc(sizeof(float)*1584); 
var=(float *)malloc(sizeof(float)*1584); 
sum=(int *)malloc(sizeof(int)*1584); 
for(i = 0; i < height/8; i++) 
{ 
for(j = 0; j < width/8;j++) 
{ 
    for(k = i*8, l = 0; k < (i*8)+8; k++,l++) 
    { 
    for(m = j*8, n = 0; m < (j*8)+8; m++,n++) 
    { 
     dividedimage[(i*(width/8))][n][l] = image[m][k]; 
    } 
    } 
} 
} 
printf("\n no of grids::%d i=%d j=%d,k=%d,m=%d n=%d",(i*(width/8)),i,j,k,m,n); 

for(i1=0;i1<(i*(width/8));i1++) 
{ 
    sum[i1]=0; 
    printf("\nprinting info of %dth grid::\n",i1+1); 
    for(n1=0;n1<n;n1++) 
    { 
     for(l1=0;l1<n;l1++) 
     { 
     // printf("%5d",dividedimage[i1][j1][l1]); 
      sum[i1]=sum[i1]+(int)dividedimage[i1][j1][l1]; 
     } 
     printf("\n"); 
    } 
    mean[i1]=sum[i1]/64; 
// printf("\n sum of intensities of grid %d is ::%d and mean is %f\n",i1+1,sum[i1],mean[i1]); 
    //printf() 
    } 
for(i1=0;i1<(i*(width/8));i1++) 
{ 
    var[i1]=0; 
    printf("\nprinting info of %dth grid::\n",i1+1); 
    for(n1=0;n1<n;n1++) 
    { 
     for(l1=0;l1<n;l1++) 
     { 
      printf("%5d",dividedimage[i1][j1][l1]); 
      //sum[i1]=sum[i1]+(int)dividedimage[i1][j1][l1]; 
      var[i1]=var[i1]+pow(((int)dividedimage[i1][j1][l1]-mean[i1]),2); 
     } 
     printf("\n"); 
    } 
    var[i1]=var[i1]/64; 
printf("\n variance of grid %d is ::%f\n",i1+1,var[i1]); 

} 
    //printf() 

for (i = 0; i < 1584; i++) { 
// y[i] = var[i1]); 
printf("\n%f",var[i]); 
    fprintf (filePtr, "%5f\n", var[i]); 
} 
haar1d(var,1584); 
} 
/** The 1D Haar Transform **/ 
void haar1d(float *vec, int n) 
{ 
int i=0; 
int w=n; 
FILE *filePtr; 
    filePtr = fopen ("1dhaarwavelet.txt","w"); 
float *vecp ; 
vecp=(float *)malloc(sizeof(float)*n); 
for(i=0;i<n;i++) 
    vecp[i] = 0; 

while(w>1) 
{ 
    w/=2; 
    for(i=0;i<w;i++) 
    { 
     vecp[i] = (vec[2*i] + vec[2*i+1])/sqrt(2.0); 
     vecp[i+w] = (vec[2*i] - vec[2*i+1])/sqrt(2.0); 
    } 

    for(i=0;i<(w*2);i++) 
     vec[i] = vecp[i]; 
} 

// delete [] vecp; 
printf("\nthe 1d haarwavelet trasform is::"); 
for (i = 0; i < n; i++) { 
printf("\n%f",vec[i]); 
    fprintf (filePtr, "%5f\n", vec[i]); 
} 
} 
/** A Modified version of 1D Haar Transform, used by the 2D Haar Transform function **/ 
void haar1(float *vec, int n, int w) 
{ 
int i=0; 
float *vecp = (float *)malloc(sizeof(float)*n); 
for(i=0;i<n;i++) 
    vecp[i] = 0; 

    w/=2; 
    for(i=0;i<w;i++) 
    { 
     vecp[i] = (vec[2*i] + vec[2*i+1])/sqrt(2.0); 
     vecp[i+w] = (vec[2*i] - vec[2*i+1])/sqrt(2.0); 
    } 

    for(i=0;i<(w*2);i++) 
     vec[i] = vecp[i]; 

//  delete [] vecp; 
} 
/** The 2D Haar Transform **/ 
void haar2(float **matrix, int rows, int cols) 
{ 
float *temp_row = (float *)malloc(sizeof(float)*cols); 
float *temp_col = (float *)malloc(sizeof(float)*rows); 

int i=0,j=0; 
int w = cols, h=rows; 
while(w>1 || h>1) 
{ 
    if(w>1) 
    { 
     for(i=0;i<h;i++) 
     { 
      for(j=0;j<cols;j++) 
       temp_row[j] = matrix[i][j]; 

      haar1(temp_row,cols,w); 

      for(j=0;j<cols;j++) 
       matrix[i][j] = temp_row[j]; 
     } 
    } 

    if(h>1) 
    { 
     for(i=0;i<w;i++) 
     { 
      for(j=0;j<rows;j++) 
       temp_col[j] = matrix[j][i]; 
      haar1(temp_col, rows, h); 
      for(j=0;j<rows;j++) 
       matrix[j][i] = temp_col[j]; 
     } 
    } 

    if(w>1) 
     w/=2; 
    if(h>1) 
     h/=2; 
} 

// delete [] temp_row; 
// delete [] temp_col; 
} 
int main(){ 
char filein[100],fileout[100]; 
PPMImage *image1,*image2; 
int m,i,j; 
printf("\nEnter the input file name::"); 
gets(filein); 
image1 = readPPM(filein); 
imageDivide(filein,image1); 
    // printf("\nEnter the output file name::"); 
// gets(fileout); 
// writePPM(fileout,image1); 
float **mat = (float **)malloc(sizeof(float*)*4); 
for(m=0;m<4;m++) 
    mat[m] = (float *)malloc(sizeof(float)*4); 
mat[0][0] = 5; mat[0][1] = 6; mat[0][2] = 1; mat[0][3] = 2; 
mat[1][0] = 4; mat[1][1] = 2; mat[1][2] = 5; mat[1][3] = 5; 
mat[2][0] = 3; mat[2][1] = 1; mat[2][2] = 7; mat[2][3] = 1; 
mat[3][0] = 6; mat[3][1] = 3; mat[3][2] = 5; mat[3][3] = 1; 


haar2(mat,4,4); 
printf("\nafter 2d haarwavelet::\n"); 
for(i=0;i<4;i++) 
{ 
    for(j=0;j<4;j++) 
    { 
     printf(" %f ",mat[i][j]); 
    } 
    printf("\n"); 
} 
printf("Press any key..."); 
getchar(); 
}