jpg.cpp

实现jpeg的压缩编码功能 在demo2的工程文件中即可查看

/*******************************************************************************
Filename:	JPG.cpp
Writer	:	Dai Zhiheng.
Time	:	2005-5-14.
Description: 

***************************************************************************/
#include <fstream.h>
#include "BitFileHead.h"
#include "readOrWriteFile.h"
#include "JPG.h"
void main()
{

//定义文件
	char fileName[40]="lena256.bmp";
	char outFileName[40]="lena256.JPG";
	cout << "输入要处理的源BMP文件名(如\"C:\\\\Path1\\\\bmp1.bmp\")，如果在当前文件" <<endl;
	cout << "夹，直接写文件名及扩展名(.BMP),要求图片的长宽等于2的指数次方：" <<endl ;
	cin >> fileName;
	cout<<endl;
	cout << "输入输出的JPG文件名(如\"C:\\\\Path1\\\\bmp1.JPG\")，如果在当前文件" <<endl;
	cout << "夹，直接写文件名及扩展名(.JPG)：" <<endl ;
	cin >> outFileName;
	ifstream inFile;
	inFile.open(fileName,ios::binary);
	ofstream outFile;
	outFile.open(outFileName,ios::binary);
	cout <<endl << "………………………………………………………………………"<<endl;

//定义结构
	tagBITMAPHEADER bmfh;
	tagBITMAPINFOHEADER bmfih;

//读取图象相关信息
	bmfh.bfSize = readBfSize(inFile);
	cout <<"    文件大小为 : " <<dec <<bmfh.bfSize << " Bytes" <<endl; 

	bmfh.bfOffBits = readBfOffBits(inFile);
	cout <<"    数据区偏移位置 : " <<bmfh.bfOffBits <<endl;

	bmfih.biWidth = readBiWidth(inFile);
	cout <<"    图象宽度 ：" <<bmfih.biWidth<<endl;

	bmfih.biHeight = readBiHeight(inFile);
	cout <<"    图象长度 ：" <<bmfih.biHeight<<endl;	

	bmfih.biPlanes = readBiPlanes(inFile);
	cout <<"    位面个数：" <<bmfih.biPlanes <<endl;

	bmfih.biBitCount = readBiBitCount(inFile);
	cout <<"    位深度： "<<bmfih.biBitCount <<endl;

	bmfih.biSizeImage = readBiSizeImage(inFile);
	cout <<"    位图阵列大小：" ;
	//cout << bmfih.biSizeImage <<endl;
	cout <<bmfh.bfSize-bmfh.bfOffBits <<endl <<endl;


	unsigned char *pbmpHeadBUF = new unsigned char[bmfh.bfOffBits];
	unsigned char *pbmpBits = new unsigned char[bmfh.bfSize-bmfh.bfOffBits];
	double *X1 = new double[bmfih.biHeight*bmfih.biWidth];//读取原图
//从BMP文件读取数据
	inFile.seekg(0);
	inFile.read(pbmpHeadBUF,bmfh.bfOffBits);
	inFile.read(pbmpBits,bmfh.bfSize-bmfh.bfOffBits);
	inFile.close();

//将数据变为double型:pbmpBits-->X1
	for(int i=0; i<bmfih.biHeight; i++)
		for(int j=0; j<bmfih.biWidth; j++)
		{
			*(X1 + i*bmfih.biWidth + j) = (double)(*(pbmpBits + (bmfih.biHeight-i-1)*bmfih.biWidth + j));
		}
//JPG
	jpg(X1, bmfih.biHeight, bmfih.biWidth, outFile);

	delete []pbmpHeadBUF;
	delete []pbmpBits;
	delete []X1;
}