C++读取、旋转和保存 bmp 图像文件编程实现
#include <stdio.h> #include "BmpRot.h" #include "stdlib.h" #include "math.h" #include <iostream> #define PI 3.14159//圆周率宏定义 #define LENGTH_NAME_BMP 30//bmp图片文件名的最大长度 using namespace std; //变量定义 BITMAPFILEHEADER strHead; RGBQUAD strPla[256];//256色调色板 BITMAPINFOHEADER strInfo; //显示位图文件头信息 void showBmpHead(BITMAPFILEHEADER pBmpHead){ cout<<"位图文件头:"<<endl; cout<<"文件大小:"<<pBmpHead.bfSize<<endl; cout<<"保留字_1:"<<pBmpHead.bfReserved1<<endl; cout<<"保留字_2:"<<pBmpHead.bfReserved2<<endl; cout<<"实际位图数据的偏移字节数:"<<pBmpHead.bfOffBits<<endl<<endl; } void showBmpInforHead(tagBITMAPINFOHEADER pBmpInforHead){ cout<<"位图信息头:"<<endl; cout<<"结构体的长度:"<<pBmpInforHead.biSize<<endl; cout<<"位图宽:"<<pBmpInforHead.biWidth<<endl; cout<<"位图高:"<<pBmpInforHead.biHeight<<endl; cout<<"biPlanes平面数:"<<pBmpInforHead.biPlanes<<endl; cout<<"biBitCount采用颜色位数:"<<pBmpInforHead.biBitCount<<endl; cout<<"压缩方式:"<<pBmpInforHead.biCompression<<endl; cout<<"biSizeImage实际位图数据占用的字节数:"<<pBmpInforHead.biSizeImage<<endl; cout<<"X方向分辨率:"<<pBmpInforHead.biXPelsPerMeter<<endl; cout<<"Y方向分辨率:"<<pBmpInforHead.biYPelsPerMeter<<endl; cout<<"使用的颜色数:"<<pBmpInforHead.biClrUsed<<endl; cout<<"重要颜色数:"<<pBmpInforHead.biClrImportant<<endl; } int main(){ char strFile[LENGTH_NAME_BMP];//bmp文件名 IMAGEDATA *imagedata = NULL;//动态分配存储原图片的像素信息的二维数组 IMAGEDATA *imagedataRot = NULL;//动态分配存储旋转后的图片的像素信息的二维数组 int width,height;//图片的宽度和高度 cout<<"请输入所要读取的文件名:"<<endl; cin>>strFile; FILE *fpi,*fpw; fpi=fopen(strFile,"rb"); if(fpi != NULL){ //先读取文件类型 WORD bfType; fread(&bfType,1,sizeof(WORD),fpi); if(0x4d42!=bfType) { cout<<"the file is not a bmp file!"<<endl; return NULL; } //读取bmp文件的文件头和信息头 fread(&strHead,1,sizeof(tagBITMAPFILEHEADER),fpi); //showBmpHead(strHead);//显示文件头 fread(&strInfo,1,sizeof(tagBITMAPINFOHEADER),fpi); //showBmpInforHead(strInfo);//显示文件信息头 //读取调色板 for(unsigned int nCounti=0;nCounti<strInfo.biClrUsed;nCounti++) { //存储的时候,一般去掉保留字rgbReserved fread((char *)&strPla[nCounti].rgbBlue,1,sizeof(BYTE),fpi); fread((char *)&strPla[nCounti].rgbGreen,1,sizeof(BYTE),fpi); fread((char *)&strPla[nCounti].rgbRed,1,sizeof(BYTE),fpi); cout<<"strPla[nCounti].rgbBlue"<<strPla[nCounti].rgbBlue<<endl; cout<<"strPla[nCounti].rgbGreen"<<strPla[nCounti].rgbGreen<<endl; cout<<"strPla[nCounti].rgbRed"<<strPla[nCounti].rgbRed<<endl; } width = strInfo.biWidth; height = strInfo.biHeight; imagedata = (IMAGEDATA*)malloc(width * height * sizeof(IMAGEDATA)); imagedataRot = (IMAGEDATA*)malloc(2 * width * 2 * height * sizeof(IMAGEDATA)); //初始化原始图片的像素数组 for(int i = 0;i < height;++i) { for(int j = 0;j < width;++j) { (*(imagedata + i * width + j)).blue = 0; (*(imagedata + i * width + j)).green = 0; (*(imagedata + i * width + j)).red = 0; } } //初始化旋转后图片的像素数组 for(int i = 0;i < 2 * height;++i) { for(int j = 0;j < 2 * width;++j) { (*(imagedataRot + i * 2 * width + j)).blue = 0; (*(imagedataRot + i * 2 * width + j)).green = 0; (*(imagedataRot + i * 2 * width + j)).red = 0; } } //fseek(fpi,54,SEEK_SET); //读出图片的像素数据 fread(imagedata,sizeof(struct tagIMAGEDATA) * width,height,fpi); /* for(int i = 0;i < height;++i) { fread(imagedata + i * width * sizeof(IMAGEDATA),sizeof(struct tagIMAGEDATA) * width,height,fpi); }*/ fclose(fpi); } else { cout<<"file open error!"<<endl; return NULL; } //图片旋转处理 int RotateAngle;//要旋转的角度数 double angle;//要旋转的弧度数 int midX_pre,midY_pre,midX_aft,midY_aft;//旋转所围绕的中心点的坐标 midX_pre = width / 2; midY_pre = height / 2; midX_aft = width; midY_aft = height; int pre_i,pre_j,after_i,after_j;//旋转前后对应的像素点坐标 cout<<"输入要旋转的角度(0度到360度,逆时针旋转):"<<endl; cin>>RotateAngle; angle = 1.0 * RotateAngle * PI / 180; for(int i = 0;i < 2 * height;++i) { for(int j = 0;j < 2 * width;++j) { after_i = i - midY_aft;//坐标变换 after_j = j - midX_aft; pre_i = (int)(cos((double)angle) * after_i - sin((double)angle) * after_j) + midY_pre; pre_j = (int)(sin((double)angle) * after_i + cos((double)angle) * after_j) + midX_pre; if(pre_i >= 0 && pre_i < height && pre_j >= 0 && pre_j < width)//在原图范围内 *(imagedataRot + i * 2 * width + j) = *(imagedata + pre_i * width + pre_j); } } //保存bmp图片 if((fpw=fopen("b.bmp","wb"))==NULL) { cout<<"create the bmp file error!"<<endl; return NULL; } WORD bfType_w=0x4d42; fwrite(&bfType_w,1,sizeof(WORD),fpw); //fpw +=2; fwrite(&strHead,1,sizeof(tagBITMAPFILEHEADER),fpw); strInfo.biWidth = 2 * width; strInfo.biHeight = 2 * height; fwrite(&strInfo,1,sizeof(tagBITMAPINFOHEADER),fpw); //保存调色板数据 for(unsigned int nCounti=0;nCounti<strInfo.biClrUsed;nCounti++) { fwrite(&strPla[nCounti].rgbBlue,1,sizeof(BYTE),fpw); fwrite(&strPla[nCounti].rgbGreen,1,sizeof(BYTE),fpw); fwrite(&strPla[nCounti].rgbRed,1,sizeof(BYTE),fpw); } //保存像素数据 for(int i =0;i < 2 * height;++i) { for(int j = 0;j < 2 * width;++j) { fwrite( &(*(imagedataRot + i * 2 * width + j)).red,1,sizeof(BYTE),fpw);//注意三条语句的顺序:否则颜色会发生变化 fwrite( &(*(imagedataRot + i * 2 * width + j)).green,1,sizeof(BYTE),fpw); fwrite( &(*(imagedataRot + i * 2 * width + j)).blue,1,sizeof(BYTE),fpw); } } fclose(fpw); //释放内存 delete[] imagedata; delete[] imagedataRot; }
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