/* File name: bmpTest.c
Author: WanChuan XianSheng
Date: Oct 01, 2011
Description: Show all Info a bmp file has. including
FileHeader Info, InfoHeader Info and Data Part.

Reference: BMP圖像數(shù)據(jù)的C語(yǔ)言讀取源碼
*/

#include
#include

#define BITMAPFILEHEADERLENGTH 14 // The bmp FileHeader length is 14
#define BM 19778 // The ASCII code for BM

/* Test the file is bmp file or not */
void bmpFileTest(FILE* fpbmp);
/* To get the OffSet of header to data part */
void bmpHeaderPartLength(FILE* fpbmp);
/* To get the width and height of the bmp file */
void BmpWidthHeight(FILE* fpbmp);
/* Show bmp file tagBITMAPFILEHEADER info */
void bmpFileHeader(FILE* fpbmp);
/* Show bmp file tagBITMAPINFOHEADER info */
void bmpInfoHeader(FILE* fpbmp);
/* Show the Data Part of bmp file */
void bmpDataPart(FILE* fpbmp);

unsigned int OffSet = 0; // OffSet from Header part to Data Part
long BmpWidth = 0; // The Width of the Data Part
long BmpHeight = 0; // The Height of the Data Part

int main(int argc, char* argv[])
{
/* Open bmp file */
FILE *fpbmp = fopen("lena.bmp", "r+");
if (fpbmp == NULL)
{
fprintf(stderr, "Open lena.bmp failed!!!/n");
return 1;
}

bmpFileTest(fpbmp); //Test the file is bmp file or not
bmpHeaderPartLength(fpbmp); //Get the length of Header Part
BmpWidthHeight(fpbmp); //Get the width and width of the Data Part
//bmpFileHeader(fpbmp); //Show the FileHeader Information
//bmpInfoHeader(fpbmp); //Show the InfoHeader Information
bmpDataPart(fpbmp); //Reserve the data to file

fclose(fpbmp);
return 0;
}

/* Test the file is bmp file or not */
void bmpFileTest(FILE* fpbmp)
{
unsigned short bfType = 0;
fseek(fpbmp, 0L, SEEK_SET);
fread(&bfType, sizeof(char), 2, fpbmp);
if (BM != bfType)
{
fprintf(stderr, "This file is not bmp file.!!!/n");
exit(1);
}
}

/* To get the OffSet of header to data part */
void bmpHeaderPartLength(FILE* fpbmp)
{
fseek(fpbmp, 10L, SEEK_SET);
fread(&OffSet, sizeof(char), 4, fpbmp);
//printf("The Header Part is of length %d./n", OffSet);
}

/* To get the width and height of the bmp file */
void BmpWidthHeight(FILE* fpbmp)
{
fseek(fpbmp, 18L, SEEK_SET);
fread(&BmpWidth, sizeof(char), 4, fpbmp);
fread(&BmpHeight, sizeof(char), 4, fpbmp);
//printf("The Width of the bmp file is %ld./n", BmpWidth);
//printf("The Height of the bmp file is %ld./n", BmpHeight);
}

/* Show bmp file tagBITMAPFILEHEADER info */
void bmpFileHeader(FILE* fpbmp)
{
unsigned short bfType; //UNIT bfType;
unsigned int bfSize; //DWORD bfSize;
unsigned short bfReserved1; //UINT bfReserved1;
unsigned short bfReserved2; //UINT bfReserved2;
unsigned int bfOffBits; //DWORD bfOffBits;

fseek(fpbmp, 0L, SEEK_SET);

fread(&bfType, sizeof(char), 2, fpbmp);
fread(&bfSize, sizeof(char), 4, fpbmp);
fread(&bfReserved1, sizeof(char), 2, fpbmp);
fread(&bfReserved2, sizeof(char), 2, fpbmp);
fread(&bfOffBits, sizeof(char), 4, fpbmp);

printf("************************************************/n");
printf("*************tagBITMAPFILEHEADER info***********/n");
printf("************************************************/n");
printf("bfType is %d./n", bfType);
printf("bfSize is %d./n", bfSize);
printf("bfReserved1 is %d./n", bfReserved1);
printf("bfReserved2 is %d./n", bfReserved2);
printf("bfOffBits is %d./n", bfOffBits);
}

/* Show bmp file tagBITMAPINFOHEADER info */
void bmpInfoHeader(FILE* fpbmp)
{
unsigned int biSize; // DWORD biSize;
long biWidth; // LONG biWidth;
long biHeight; // LONG biHeight;
unsigned int biPlanes; // WORD biPlanes;
unsigned int biBitCount; // WORD biBitCount;
unsigned int biCompression; // DWORD biCompression;
unsigned int biSizeImage; // DWORD biSizeImage;
long biXPelsPerMerer; // LONG biXPelsPerMerer;
long biYPelsPerMerer; // LONG biYPelsPerMerer;
unsigned int biClrUsed; // DWORD biClrUsed;
unsigned int biClrImportant; // DWORD biClrImportant;

fseek(fpbmp, 14L, SEEK_SET);

fread(&biSize, sizeof(char), 4, fpbmp);
fread(&biWidth, sizeof(char), 4, fpbmp);
fread(&biHeight, sizeof(char), 4, fpbmp);
fread(&biPlanes, sizeof(char), 4, fpbmp);
fread(&biBitCount, sizeof(char), 4, fpbmp);
fread(&biCompression, sizeof(char), 4, fpbmp);
fread(&biSizeImage, sizeof(char), 4, fpbmp);
fread(&biXPelsPerMerer, sizeof(char), 4, fpbmp);
fread(&biYPelsPerMerer, sizeof(char), 4, fpbmp);
fread(&biClrUsed, sizeof(char), 4, fpbmp);
fread(&biClrImportant, sizeof(char), 4, fpbmp);

printf("************************************************/n");
printf("*************tagBITMAPINFOHEADER info***********/n");
printf("************************************************/n");
printf("biSize is %d. /n", biSize);
printf("biWidth is %ld./n", biWidth);
printf("biHeight is %ld./n", biHeight);
printf("biPlanes is %d. /n", biPlanes);
printf("biBitCount is %d. /n", biBitCount);
printf("biCompression is %d. /n", biCompression);
printf("biSizeImage is %d. /n", biSizeImage);
printf("biXPelsPerMerer is %ld./n", biXPelsPerMerer);
printf("biYPelsPerMerer is %ld./n", biYPelsPerMerer);
printf("biClrUsed is %d. /n", biClrUsed);
printf("biClrImportant is %d. /n", biClrImportant);
}

/* Show the Data Part of bmp file */
void bmpDataPart(FILE* fpbmp)
{
int i, j;
unsigned char bmpPixel[BmpWidth][BmpHeight];
unsigned char* bmpPixelTmp = NULL;
FILE* fpDataBmp;

/* New a file to save the data matrix */
if((fpDataBmp=fopen("bmpData.dat","w+")) == NULL)
{
fprintf(stderr, "Failed to construct file bmpData.dat.!!!");
exit(1);
}

fseek(fpbmp, OffSet, SEEK_SET);
if ((bmpPixelTmp=(unsigned char*)malloc(sizeof(char)*BmpWidth*BmpHeight))==NULL)
{
fprintf(stderr, "Data allocation failed.!!!/n");
exit(1);
}
fread(bmpPixelTmp, sizeof(char), BmpWidth*BmpHeight, fpbmp);

/* Read the data to Matrix and save it in file bmpData.dat */
for(i =0; i < BmpHeight; i++)
{
fprintf(fpDataBmp, "The data in line %-3d:/n", i+1);
for(j = 0; j < BmpWidth; j++)
{
bmpPixel[i][j] = bmpPixelTmp[BmpWidth*(BmpHeight-1-i)+j];
//fwrite(&chartmp, sizeof(char), 1, fpDataBmp);
fprintf(fpDataBmp, "%-3d ", bmpPixel[i][j]);
if ((j+1)%32 == 0)
{
fprintf(fpDataBmp, "/n");
}
}
}
/* Used to test the data read is true or false
You can open the file using Matlab to compare the data */
//printf("bmpPixel[2][3] is %d./n", bmpPixel[2][3]);
//printf("bmpPixel[20][30] is %d./n", bmpPixel[20][30]);

free(bmpPixelTmp);
fclose(fpDataBmp);
}