BMP文件右旋90度［c语言］

#include <stdio.h>#include <stdlib.h>#include <math.h>typedef unsigned short WORD;typedef unsigned int DWORD;typedef unsigned int LONG;#pragma pack(2)typedef struct tagBITMAPFILEHEADER{    WORD bfType;    DWORD bfSize;    WORD bfReserved1;    WORD bfReserved2;    DWORD bfOffBits;} BITMAPFILEHEADER;#pragma pack()typedef struct tagBITMAPINFOHEADER{    DWORD biSize;    LONG biWidth;    LONG biHeight;    WORD biPlanes;    WORD biBitCount;    DWORD biCompression;    DWORD biSizeImage;    LONG biXPelsPerMeter;    LONG biYPelsPerMeter;    DWORD biClrUsed;    DWORD biClrImportant;} BITMAPINFOHEADER;/* fname- 输入文件名称 foname-输出文件名 */void cw90(char *fname,char *foname) {        BITMAPFILEHEADER fileHeader;    BITMAPINFOHEADER infoHeader;    unsigned char palette[8];    FILE *f = fopen(fname,"rb");        if(f == NULL) {        printf("Can not find file %s\n",fname);        return;    }        fread(&fileHeader,sizeof(BITMAPFILEHEADER),1,f);    fread(&infoHeader,sizeof(BITMAPINFOHEADER),1,f);    fread(palette,sizeof(unsigned char),8,f);        unsigned char *data = (unsigned char*)malloc(infoHeader.biSizeImage);        fread(data,sizeof(unsigned char),infoHeader.biSizeImage,f);        FILE *of = fopen(foname,"wb");            BITMAPFILEHEADER oFileHeader;    BITMAPINFOHEADER oInfoHeader;        int lineSize = ( infoHeader.biHeight + 31) / 32 * 4;    int imageSize = lineSize * infoHeader.biWidth;        // ////////////////////////    oFileHeader.bfType = 19778;    oFileHeader.bfSize = 62 + imageSize;    oFileHeader.bfReserved1 = 0;    oFileHeader.bfReserved2 = 0;    oFileHeader.bfOffBits = 62;    // ////////////////////////    oInfoHeader.biSize = 40;    oInfoHeader.biWidth = infoHeader.biHeight;    oInfoHeader.biHeight = infoHeader.biWidth;    oInfoHeader.biPlanes = 1;    oInfoHeader.biBitCount = 1;    oInfoHeader.biCompression = 0;    oInfoHeader.biSizeImage = imageSize;    oInfoHeader.biXPelsPerMeter = 0;    oInfoHeader.biYPelsPerMeter = 0;    oInfoHeader.biClrUsed = 0;    oInfoHeader.biClrImportant = 0;    // ////////////////////////        fwrite( &oFileHeader , sizeof(BITMAPFILEHEADER) , 1 , of );    fwrite( &oInfoHeader , sizeof(BITMAPINFOHEADER) , 1 , of );    fwrite( palette , 1 , 8 , of );            unsigned char *first = (unsigned char*)malloc(infoHeader.biHeight * oInfoHeader.biHeight);    unsigned char *second = (unsigned char*)malloc(infoHeader.biHeight * oInfoHeader.biHeight);    int myline = oInfoHeader.biSizeImage / oInfoHeader.biHeight;    unsigned char *third = (unsigned char*)malloc(myline * 8 * oInfoHeader.biHeight);    unsigned char *forth = (unsigned char*)malloc(myline * oInfoHeader.biHeight);    unsigned char *img = (unsigned char*)malloc(oInfoHeader.biSizeImage);        // first step    int i,j,k,t = -1;    int temp = infoHeader.biSizeImage / infoHeader.biHeight;    for(i = 0; i < infoHeader.biHeight; i++) {        for(j = 0; j < temp; j++) {            for(k = 0; k < 8; k++) {                if(j*8 + k < oInfoHeader.biHeight) {                    first[++t] = data[i * temp + j] >> (8-1-k) & 1;                          }            }        }    }        // second step    // rotate    t = -1;    for(i = 0; i < oInfoHeader.biHeight; i++) {        for(j = 0; j < infoHeader.biHeight; j++) {            second[++t] = first[oInfoHeader.biHeight*j + oInfoHeader.biHeight - i - 1];        }    }        // step three    // fill with 0's    t = -1;    for(i = 0; i < oInfoHeader.biHeight; i++) {        for(j = 0; j < infoHeader.biHeight; j++) {            third[++t] = second[i*infoHeader.biHeight + j];        }        for(k = infoHeader.biHeight; k < myline * 8; k++) {            third[++t] = 0;        }    }        // step four    // transfer    int u = -1;    int m = -1;    for(i = 0; i < oInfoHeader.biHeight; i++) {        for(j = 0; j < myline * 8; j++) {            int sum = 0;            for(k = 0; k < 8; k++) {                sum += pow(2,8-k-1)*third[++m%t];            }            forth[++u] = sum;        }    }        fwrite( forth , 1 , myline * oInfoHeader.biHeight , of );        free(img);    free(data);        fclose(f);    fclose(of);     }int main() {    cw90("original.bmp","ttt.bmp");    system("pause");    return 0;}

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代码在vs2010, os X 10.8.0 上测试通过。在windows上运行失败可将 typedef unsigned int LONG 修改成 typedef unsigned long LONG.

［上述代码适用于单色BMP文件](biBitCount = 1)

上述方法有问题，正确的请参[http://201211131343.iteye.com/blog/1992364
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