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C语言实现BMP图像处理(直方图均衡化)

2024-04-02 19:55

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本文实例为大家分享了C语言实现BMP图像直方图均衡化处理的具体代码，供大家参考，具体内容如下

计算步骤：

1）统计各灰度值的概率；

2）计算了累积概率直方图（CDF）；

3）取整扩展：Tk = int[ (L-1)*Tk];


#include <Windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
 
int main(int* argc, char** argv)
{
 FILE* fp = fopen("./01.bmp", "rb");
 if (fp == 0)
  return 0;
 BITMAPFILEHEADER fileHead;
 fread(&fileHead, sizeof(BITMAPFILEHEADER), 1, fp);
 
 BITMAPINFOHEADER infoHead;
 fread(&infoHead, sizeof(BITMAPINFOHEADER), 1, fp);
 int width = infoHead.biWidth;
 int height = infoHead.biHeight;
 int biCount = infoHead.biBitCount;
 
 int lineByte = (biCount*width / 8 + 3) / 4 * 4;
 RGBQUAD* pColorTable;
 pColorTable = new RGBQUAD[256];
 fread(pColorTable, sizeof(RGBQUAD), 256, fp);
 
 unsigned char* pBmpBuf;
 pBmpBuf = new unsigned char[lineByte*height];
 fread(pBmpBuf, lineByte*height, 1, fp);
 fclose(fp);
 
 // 统计概率
 double st[256] = { 0 };
 int st1[256] = { 0 };
 int t;
 for (int i = 0; i < height; ++i){
  for (int j = 0; j < width; ++j){
   t = *(pBmpBuf + i*lineByte + j);
   st[t]++;
  }
 }
 // 计算累加直方图并完成映射
 st[0] = st[0] / (width*height);
 st1[0] = round(double((256 - 1)*st[0]));
 for (int i = 1; i < 256; ++i){
  st[i] = st[i] / (width*height);
  st[i] = st[i] + st[i - 1];
  st1[i] = int(round(double((256 - 1)*st[i])));
  printf("st[i] = %d, st1[t] = %d\n", st[i], st1[i]);
 }
 
 // 新图像的像素填充
 unsigned char* pBmpBuf1;
 pBmpBuf1 = new unsigned char[lineByte*height];
 for (int i = 0; i < height; ++i){
  for (int j = 0; j < width; ++j){
   t = *(pBmpBuf + i*lineByte + j);
   *(pBmpBuf1 + i*lineByte + j) = st1[t];
  }
 }
 
 FILE* fop = fopen("./imhist.bmp", "wb");
 if (fop == 0)
  return 0;
 fwrite(&fileHead, sizeof(BITMAPFILEHEADER), 1, fop);
 fwrite(&infoHead, sizeof(BITMAPINFOHEADER), 1, fop);
 fwrite(pColorTable, sizeof(RGBQUAD), 256, fop);
 fwrite(pBmpBuf1, lineByte*height, 1, fop);
 fclose(fop);
 
 system("pause");
 return 0;
}

实验结果：