project.c

这个东西可以压缩bmp形式的文件

#include<stdio.h>
#include<process.h>
typedef unsigned char BYTE;
typedef unsigned short WORD;
typedef unsigned long DWORD;
typedef unsigned int UINT;
typedef signed long LONG;
typedef struct tagBITMAPFILEHEADER
{
	UINT bfType;
	DWORD bfSize;
	UINT bfReserved1;
	UINT bfReserved2;
	DWORD bfoffBIts;
	}BITMAPFILEHEADER;
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;
	BITMAPINFOHEADER bitfile;
	BITMAPINFOHEADER bitinfo;
	FILE * fpi, *fpo;
	long offset,sum,count,width,height;
	int i,repcount;
	char data,datatp;
void compress(char filei[12],char fileo[12]){
	if((fpi=fopen(filei,"rb"))==NULL)
	{
		printf("can not open DIB file");
		exit(1);
		}
	if((fpo=fopen(fileo,"wb"))==NULL)
	{
		printf("can not create a file");
		exit(1);
		}
	fread(&bitfile,sizeof(BITMAPFILEHEADER),1,fpi);
	fread(&bitinfo,sizeof(BITMAPINFOHEADER),1,fpi);
	offset=bitinfo.biWidth;
	height=bitinfo.biHeight;
	rewind(fpi);
	for(i=0;i<offset;i++)fprintf(fpo,"%c",getc(fpi));
	if(bitinfo.biBitCount==4) sum=(width*height)/2;
	if(bitinfo.biBitCount==8) sum=width*height;
	count=01;
	data=getc(fpi);
	do{
	datatp=getc(fpi);
	count++;
	repcount=1;
	while((data==datatp)&&(repcount<63)&&(count<sum))
	{
		repcount ++;
		datatp=getc(fpi);
		count++;
		}
	if ((repcount >1)||(unsigned int)data>0xbf)
	{
		repcount +=0xc0;
		fprintf(fpo,"%c",repcount);
		
		}
		fprintf(fpo,"%c",data);
		data=datatp;
			
	}while(count<sum);
	fclose(fpi);
	fclose(fpo);
	return;
}


void decompress(char filei[12],char fileo[12]){
	if((fpi=fopen(filei,"rb"))==NULL){
		printf("can not open a compressed file");
		exit(1);
		}
	if((fpo=fopen(fileo,"wb"))==NULL)
	{
		printf("can not create a file");
		exit(1);
		}
	fread(&bitfile,sizeof(BITMAPFILEHEADER),1,fpi);
	fread(&bitinfo,sizeof(BITMAPINFOHEADER),1,fpi);
	offset=bitinfo.biWidth;
	height=bitinfo.biHeight;
	rewind(fpi);
	for(i=0;i<offset;i++) fprintf(fpo,"%c",getc(fpi));
	if(bitinfo.biBitCount==4) sum=(width*height)/2;
	if(bitinfo.biBitCount==8) sum=width*height;
	count=01;
	do{
	data=getc(fpi);
	if(((data&0xc0)>>6)==3)
	{
		repcount=data&0x3f;
		data=getc(fpi);
		for(i=0;i<repcount;i++)
		{
			fprintf(fpo,"%c",data);
			count++;
			}
		}else{
		fprintf(fpo,"%c",data);
		count++;
		}
	}while(count<sum);
	fclose(fpi);
	fclose(fpo);
	return;
	}

void main(int argc,char *argv[])
{
decompress("a.bmp","b.bmp");
decompress("b.bmp","c.bmp");
}