简单jpeg编码程序
简单jpeg编码程序 simplejpegenc.h
/*
这是一个简单的jpeg编码程序，支持1：1：1采样的baseline彩色jpeg，输入只能是24bit的BMP文件
代码结构只求能说明各步骤过程，并不做特别的优化，效率较为一般。
*/
#ifndef __JENC__
#define __JENC__
#include <string>
#include <windows.h>
#include <stdio.h>
#include <malloc.h>
#include <math.h>
#include "jpeg.h"
#include "jpegformat.h"
using namespace std;
class JEnc
{
public:
// bmFile:输入文件
// jpgFile:输出文件
// Q:质量
void Invoke(string bmFile, string jpgFile, long Q)
{
FILE* pFile; // 输入文件句柄
if ((pFile = fopen(bmFile.c_str(),"rb")) == NULL) // 打开文件
{
throw("open bmp file error.");
}
// 获取jpeg编码需要的bmp数据结构，jpeg要求数据缓冲区的高和宽为8或16的倍数(视采样方式而定)
BMBUFINFO bmBuffInfo = GetBMBuffSize(pFile);
imgWidth = bmBuffInfo.imgWidth; // 图像宽
imgHeight = bmBuffInfo.imgHeight; // 图像高
buffWidth = bmBuffInfo.buffWidth; // 缓冲宽
buffHeight = bmBuffInfo.buffHeight; // 缓冲高
size_t buffSize = buffHeight * buffWidth * 3; // 缓冲长度，因为是24bits,所以*3
BYTE* bmData = new BYTE[buffSize]; // 申请内存空间
GetBMData(pFile, bmData, bmBuffInfo); // 获取数据
fclose(pFile); // 关闭文件
//=====================================
// 计算编码需要的缓冲区，RGB信号需要别分别编码，所以需要3个缓冲区，这里只是1：1：1所以是一样大
size_t yuvBuffSize = buffWidth * buffHeight;
BYTE* pYBuff = new BYTE[yuvBuffSize];
BYTE* pUBuff = new BYTE[yuvBuffSize];
BYTE* pVBuff = new BYTE[yuvBuffSize];
// 将RGB信号转换为YUV信号
BGR2YUV111(bmData,pYBuff,pUBuff,pVBuff);
// 将信号分割为8x8的块
DivBuff(pYBuff, buffWidth, buffHeight, DCTSIZE, DCTSIZE );
DivBuff(pUBuff, buffWidth, buffHeight, DCTSIZE, DCTSIZE );
DivBuff(pVBuff, buffWidth, buffHeight, DCTSIZE, DCTSIZE );
SetQuantTable(std_Y_QT,YQT, Q); // 设置Y量化表
SetQuantTable(std_UV_QT,UVQT, Q); // 设置UV量化表
InitQTForAANDCT(); // 初始化AA&N需要的量化表
pVLITAB=VLI_TAB + 2047; // 设置VLI_TAB的别名
BuildVLITable(); // 计算VLI表
pOutFile = fopen(jpgFile.c_str(),"wb");
// 写入各段
WriteSOI();
WriteAPP0();
WriteDQT();
WriteSOF();
WriteDHT();
WriteSOS();
// 计算Y/UV信号的交直分量的huffman表，这里使用标准的huffman表，并不是计算得出，缺点是文件略长，但是速度快
BuildSTDHuffTab(STD_DC_Y_NRCODES,STD_DC_Y_VALUES,STD_DC_Y_HT);
BuildSTDHuffTab(STD_AC_Y_NRCODES,STD_AC_Y_VALUES,STD_AC_Y_HT);
BuildSTDHuffTab(STD_DC_UV_NRCODES,STD_DC_UV_VALUES,STD_DC_UV_HT);
BuildSTDHuffTab(STD_AC_UV_NRCODES,STD_AC_UV_VALUES,STD_AC_UV_HT);
// 处理单元数据
ProcessData(pYBuff,pUBuff,pVBuff);
WriteEOI();
fclose(pOutFile);
delete[] bmData;
}
private:
FILE* pOutFile;
int buffWidth;
int buffHeight;
int imgWidth;
int imgHeight;
// 获取BMP文件输出缓冲区信息
BMBUFINFO GetBMBuffSize(FILE* pFile)
{
BITMAPFILEHEADER bmHead; //文件头信息块
BITMAPINFOHEADER bmInfo; //图像描述信息块
BMBUFINFO bmBuffInfo;
UINT colSize = 0;
UINT rowSize = 0;
fseek(pFile,0,SEEK_SET); //将读写指针指向文件头部
fread(&bmHead,sizeof(bmHead),1,pFile); //读取文件头信息块
fread(&bmInfo,sizeof(bmInfo),1,pFile); //读取位图信息块
// 计算填充后列数，jpeg编码要求缓冲区的高和宽为8或16的倍数
if (bmInfo.biWidth % 8 == 0)
{
colSize = bmInfo.biWidth;
}
else
{
colSize = bmInfo.biWidth + 8 - (bmInfo.biWidth % 8);
}
// 计算填充后行数
if (bmInfo.biHeight % 8 == 0)
{
rowSize = bmInfo.biHeight;
}
else
{
rowSize = bmInfo.biHeight + 8 - (bmInfo.biHeight % 8);
}
bmBuffInfo.BitCount = 24;
bmBuffInfo.buffHeight = rowSize; // 缓冲区高
bmBuffInfo.buffWidth = colSize; // 缓冲区宽
bmBuffInfo.imgHeight = bmInfo.biHeight; // 图像高
bmBuffInfo.imgWidth = bmInfo.biWidth; // 图像宽
return bmBuffInfo;
}
// 获取图像数据
void GetBMData(FILE* pFile, BYTE* pBuff, BMBUFINFO buffInfo)
{
BITMAPFILEHEADER bmHead; // 文件头信息块
BITMAPINFOHEADER bmInfo; // 图像描述信息块
size_t dataLen = 0; // 文件数据区长度
long alignBytes = 0; // 为对齐4字节需要补足的字节数
UINT lineSize = 0;
fseek(pFile,0,SEEK_SET); // 将读写指针指向文件头部
fread(&bmHead,sizeof(bmHead),1,pFile); // 读取文件头信息块
fread(&bmInfo,sizeof(bmInfo),1,pFile); // 读取位图信息块
//计算对齐的字节数
alignBytes = (((bmInfo.biWidth * bmInfo.biBitCount) + 31) & ~31) / 8L
- (bmInfo.biWidth * bmInfo.biBitCount) / 8L; // 计算图象文件数据段行补齐字节数
//计算数据缓冲区长度
lineSize = bmInfo.biWidth * 3;
// 因为bmp文件数据是倒置的所以从最后一行开始读
for (int i = bmInfo.biHeight - 1; i >= 0; --i)
{
fread(&pBuff[buffInfo.buffWidth * i * 3],lineSize,1,pFile);
fseek(pFile,alignBytes,SEEK_CUR); // 跳过对齐字节
}
}
// 转换色彩空间BGR-YUV,111采样
void BGR2YUV111(BYTE* pBuf, BYTE* pYBuff, BYTE* pUBuff, BYTE* pVBuff)
{
DOUBLE tmpY = 0; //临时变量
DOUBLE tmpU = 0;
DOUBLE tmpV = 0;
BYTE tmpB = 0;
BYTE tmpG = 0;
BYTE tmpR = 0;
UINT i = 0;
size_t elemNum = _msize(pBuf) / 3; //缓冲长度
for (i = 0; i < elemNum; i++)
{
tmpB = pBuf[i * 3];
tmpG = pBuf[i * 3 + 1];
tmpR = pBuf[i * 3 + 2];
tmpY = 0.299 * tmpR + 0.587 * tmpG + 0.114 * tmpB;
tmpU = -0.1687 * tmpR - 0.3313 * tmpG + 0.5 * tmpB + 128;
tmpV = 0.5 * tmpR - 0.4187 * tmpG - 0.0813 * tmpB + 128;
//if(tmpY > 255){tmpY = 255;} //输出限制
//if(tmpU > 255){tmpU = 255;}
//if(tmpV > 255){tmpV = 255;}
//if(tmpY < 0){tmpY = 0;}
//if(tmpU < 0){tmpU = 0;}
//if(tmpV < 0){tmpV = 0;}
pYBuff[i] = tmpY; //放入输入缓冲
pUBuff[i] = tmpU;
pVBuff[i] = tmpV;
}
}
//********************************************************************
// 方法名称:DivBuff
// 最后修订日期:2003.5.3
//
// 参数说明:
// lpBuf:输入缓冲,处理后的数据也存储在这里
// width:缓冲X方向长度
// height:缓冲Y方向长度
// xLen:X方向切割长度
// yLen:Y方向切割长度
//********************************************************************
void DivBuff(BYTE* pBuf,UINT width,UINT height,UINT xLen,UINT yLen)
{
UINT xBufs = width / xLen; //X轴方向上切割数量
UINT yBufs = height / yLen; //Y轴方向上切割数量
UINT tmpBufLen = xBufs * xLen * yLen; //计算临时缓冲区长度
BYTE* tmpBuf = new BYTE[tmpBufLen]; //创建临时缓冲
UINT i = 0; //临时变量
UINT j = 0;
UINT k = 0;
UINT n = 0;
UINT bufOffset = 0; //切割开始的偏移量
for (i = 0; i < yBufs; ++i) //循环Y方向切割数量
{
n = 0; //复位临时缓冲区偏移量
for (j = 0; j < xBufs; ++j) //循环X方向切割数量
{
bufOffset = yLen * xLen * i * xBufs + j * xLen; //计算单元信号块的首行偏移量
for (k = 0; k < yLen; ++k) //循环块的行数
{
memcpy(&tmpBuf[n],&pBuf[bufOffset],xLen); //复制一行到临时缓冲
n += xLen; //计算临时缓冲区偏移量
bufOffset += width; //计算输入缓冲区偏移量
}
}
memcpy(&pBuf[i * tmpBufLen],tmpBuf,tmpBufLen); //复制临时缓冲数据到输入缓冲
}
delete[] tmpBuf; //删除临时缓冲
}
//********************************************************************
// 方法名称:SetQuantTable
//
// 方法说明:根据所需质量设置量化表
//
// 参数说明:
// std_QT:标准量化表
// QT:输出量化表
// Q:质量参数
//********************************************************************
// 根据所需质量设置量化表
void SetQuantTable(const BYTE* std_QT,BYTE* QT, int Q)
{
INT tmpVal = 0; //临时变量
DWORD i = 0;
if (Q < 1) Q = 1; //限制质量系数
if (Q > 100) Q = 100;
//非线性映射 1->5000, 10->500, 25->200, 50->100, 75->50, 100->0
if (Q < 50)
{
Q = 5000 / Q;
}
else
{
Q = 200 - Q * 2;
}
for (i = 0; i < DCTBLOCKSIZE; ++i)
{
tmpVal = (std_QT[i] * Q + 50L) / 100L;
if (tmpVal < 1) //数值范围限定
{
tmpVal = 1L;
}
if (tmpVal > 255)
{
tmpVal = 255L;
}
QT[FZBT[i]] = static_cast<BYTE>(tmpVal);
}
}
//为float AA&N IDCT算法初始化量化表
void InitQTForAANDCT()
{
UINT i = 0; //临时变量
UINT j = 0;
UINT k = 0;
for (i = 0; i < DCTSIZE; i++) //初始化亮度信号量化表
{
for (j = 0; j < DCTSIZE; j++)
{
YQT_DCT[k] = (FLOAT) (1.0 / ((DOUBLE) YQT[FZBT[k]] *
aanScaleFactor[i] * aanScaleFactor[j] * 8.0));
++k;
}
}
k = 0;
for (i = 0; i < DCTSIZE; i++) //初始化色差信号量化表
{
for (j = 0; j < DCTSIZE; j++)
{
UVQT_DCT[k] = (FLOAT) (1.0 / ((DOUBLE) UVQT[FZBT[k]] *
aanScaleFactor[i] * aanScaleFactor[j] * 8.0));
++k;
}
}
}
//写文件开始标记
void WriteSOI(void)
{
fwrite(&SOITAG,sizeof(SOITAG),1,this->pOutFile);
}
//写APP0段
void WriteAPP0(void)
{
JPEGAPP0 APP0;
APP0.segmentTag = 0xE0FF;
APP0.length = 0x1000;
APP0.id[0] = 'J';
APP0.id[1] = 'F';
APP0.id[2] = 'I';
APP0.id[3] = 'F';
APP0.id[4] = 0;
APP0.ver = 0x0101;
APP0.densityUnit = 0x00;
APP0.densityX = 0x0100;
APP0.densityY = 0x0100;
APP0.thp = 0x00;
APP0.tvp = 0x00;
fwrite(&APP0,sizeof(APP0),1,this->pOutFile);
}
//写入DQT段
void WriteDQT(void)
{
UINT i = 0;
JPEGDQT_8BITS DQT_Y;
DQT_Y.segmentTag = 0xDBFF;
DQT_Y.length = 0x4300;
DQT_Y.tableInfo = 0x00;
for (i = 0; i < DCTBLOCKSIZE; i++)
{
DQT_Y.table[i] = YQT[i];
}
fwrite(&DQT_Y,sizeof(DQT_Y),1,this->pOutFile);
DQT_Y.tableInfo = 0x01;
for (i = 0; i < DCTBLOCKSIZE; i++)
{
DQT_Y.table[i] = UVQT[i];
}
fwrite(&DQT_Y,sizeof(DQT_Y),1,this->pOutFile);
}
//写入SOF段
void WriteSOF(void)
{
JPEGSOF0_24BITS SOF;
SOF.segmentTag = 0xC0FF;
SOF.length = 0x1100;
SOF.precision = 0x08;
SOF.height = Intel2Moto(USHORT(this->imgHeight));
SOF.width = Intel2Moto(USHORT(this->imgWidth));
SOF.sigNum = 0x03;
SOF.YID = 0x01;
SOF.QTY = 0x00;
SOF.UID = 0x02;
SOF.QTU = 0x01;
SOF.VID = 0x03;
SOF.QTV = 0x01;
SOF.HVU = 0x11;
SOF.HVV = 0x11;
/*switch (this->SamplingType)
{
case 1:
SOF.HVY = 0x11;
break;
case 2:
SOF.HVY = 0x12;
break;
case 3:
SOF.HVY = 0x21;
break;
case 4:
SOF.HVY = 0x22;
break;
}*/
SOF.HVY = 0x11;
fwrite(&SOF,sizeof(SOF),1,this->pOutFile);
}
//写入DHT段
void WriteDHT(void)
{
UINT i = 0;
JPEGDHT DHT;
DHT.segmentTag = 0xC4FF;
DHT.length = Intel2Moto(19 + 12);
DHT.tableInfo = 0x00;
for (i = 0; i < 16; i++)
{
DHT.huffCode[i] = STD_DC_Y_NRCODES[i + 1];
}
fwrite(&DHT,sizeof(DHT),1,this->pOutFile);
for (i = 0; i <= 11; i++)
{
WriteByte(STD_DC_Y_VALUES[i]);
}
//------------------------------------------------
DHT.tableInfo = 0x01;
for (i = 0; i < 16; i++)
{
DHT.huffCode[i] = STD_DC_UV_NRCODES[i + 1];
}
fwrite(&DHT,sizeof(DHT),1,this->pOutFile);
for (i = 0; i <= 11; i++)
{
WriteByte(STD_DC_UV_VALUES[i]);
}
//----------------------------------------------------
DHT.length = Intel2Moto(19 + 162);
DHT.tableInfo = 0x10;
for (i = 0; i < 16; i++)
{
DHT.huffCode[i] = STD_AC_Y_NRCODES[i + 1];
}
fwrite(&DHT,sizeof(DHT),1,this->pOutFile);
for (i = 0; i <= 161; i++)
{
WriteByte(STD_AC_Y_VALUES[i]);
}
//-----------------------------------------------------
DHT.tableInfo = 0x11;
for (i = 0; i < 16; i++)
{
DHT.huffCode[i] = STD_AC_UV_NRCODES[i + 1];
}
fwrite(&DHT,sizeof(DHT),1,this->pOutFile);
for (i = 0; i <= 161; i++)
{
WriteByte(STD_AC_UV_VALUES[i]);
}
}
//写入SOS段
void WriteSOS(void)
{
JPEGSOS_24BITS SOS;
SOS.segmentTag = 0xDAFF;
SOS.length = 0x0C00;
SOS.sigNum = 0x03;
SOS.YID = 0x01;
SOS.HTY = 0x00;
SOS.UID = 0x02;
SOS.HTU = 0x11;
SOS.VID = 0x03;
SOS.HTV = 0x11;
SOS.Se = 0x3F;
SOS.Ss = 0x00;
SOS.Bf = 0x00;
fwrite(&SOS,sizeof(SOS),1,this->pOutFile);
}
//写入文件结束标记
void WriteEOI(void)
{
fwrite(&EOITAG,sizeof(EOITAG),1,this->pOutFile);
}
// 将高8位和低8位交换
USHORT Intel2Moto(USHORT val)
{
BYTE highBits = BYTE(val / 256);
BYTE lowBits = BYTE(val % 256);
return lowBits * 256 + highBits;
}
//写1字节到文件
void WriteByte(BYTE val)
{
fwrite(&val,sizeof(val),1,this->pOutFile);
}
// 生成标准Huffman表
void BuildSTDHuffTab(BYTE* nrcodes,BYTE* stdTab,HUFFCODE* huffCode)
{
BYTE i = 0; //临时变量
BYTE j = 0;
BYTE k = 0;
USHORT code = 0;
for (i = 1; i <= 16; i++)
{
for (j = 1; j <= nrcodes[i]; j++)
{
huffCode[stdTab[k]].code = code;
huffCode[stdTab[k]].length = i;
++k;
++code;
}
code*=2;
}
for (i = 0; i < k; i++)
{
huffCode[i].val = stdTab[i];
}
}
// 处理DU(数据单元)
void ProcessDU(FLOAT* lpBuf,FLOAT* quantTab,HUFFCODE* dcHuffTab,HUFFCODE* acHuffTab,SHORT* DC)
{
BYTE i = 0; //临时变量
UINT j = 0;
SHORT diffVal = 0; //DC差异值
BYTE acLen = 0; //熵编码后AC中间符号的数量
SHORT sigBuf[DCTBLOCKSIZE]; //量化后信号缓冲
ACSYM acSym[DCTBLOCKSIZE]; //AC中间符号缓冲
FDCT(lpBuf); //离散余弦变换
for (i = 0; i < DCTBLOCKSIZE; i++) //量化操作
{
sigBuf[FZBT[i]] = (lpBuf[i] * quantTab[i] + 16384.5) - 16384;
}
//-----------------------------------------------------
//对DC信号编码，写入文件
//DPCM编码
diffVal = sigBuf[0] - *DC;
*DC = sigBuf[0];
//搜索Huffman表，写入相应的码字
if (diffVal == 0)
{
WriteBits(dcHuffTab[0]);
}
else
{
WriteBits(dcHuffTab[pVLITAB[diffVal]]);
WriteBits(BuildSym2(diffVal));
}
//-------------------------------------------------------
//对AC信号编码并写入文件
for (i = 63; (i > 0) && (sigBuf[i] == 0); i--) //判断ac信号是否全为0
{
//注意，空循环
}
if (i == 0) //如果全为0
{
WriteBits(acHuffTab[0x00]); //写入块结束标记
}
else
{
RLEComp(sigBuf,&acSym[0],acLen); //对AC运行长度编码
for (j = 0; j < acLen; j++) //依次对AC中间符号Huffman编码
{
if (acSym[j].codeLen == 0) //是否有连续16个0
{
WriteBits(acHuffTab[0xF0]); //写入(15,0)
}
else
{
WriteBits(acHuffTab[acSym[j].zeroLen * 16 + acSym[j].codeLen]); //
WriteBits(BuildSym2(acSym[j].amplitude));
}
}
if (i != 63) //如果最后位以0结束就写入EOB
{
WriteBits(acHuffTab[0x00]);
}
}
}
//********************************************************************
// 方法名称:ProcessData
//
// 方法说明:处理图像数据FDCT-QUANT-HUFFMAN
//
// 参数说明:
// lpYBuf:亮度Y信号输入缓冲
// lpUBuf:色差U信号输入缓冲
// lpVBuf:色差V信号输入缓冲
//********************************************************************
void ProcessData(BYTE* lpYBuf,BYTE* lpUBuf,BYTE* lpVBuf)
{
size_t yBufLen = _msize(lpYBuf); //亮度Y缓冲长度
size_t uBufLen = _msize(lpUBuf); //色差U缓冲长度
size_t vBufLen = _msize(lpVBuf); //色差V缓冲长度
FLOAT dctYBuf[DCTBLOCKSIZE]; //Y信号FDCT编码临时缓冲
FLOAT dctUBuf[DCTBLOCKSIZE]; //U信号FDCT编码临时缓冲
FLOAT dctVBuf[DCTBLOCKSIZE]; //V信号FDCT编码临时缓冲
UINT mcuNum = 0; //存放MCU的数量
SHORT yDC = 0; //Y信号的当前块的DC
SHORT uDC = 0; //U信号的当前块的DC
SHORT vDC = 0; //V信号的当前块的DC
BYTE yCounter = 0; //YUV信号各自的写入计数器
BYTE uCounter = 0;
BYTE vCounter = 0;
UINT i = 0; //临时变量
UINT j = 0;
UINT k = 0;
UINT p = 0;
UINT m = 0;
UINT n = 0;
UINT s = 0;
mcuNum = (this->buffHeight * this->buffWidth * 3)
/ (DCTBLOCKSIZE * 3); //计算MCU的数量
for (p = 0;p < mcuNum; p++) //依次生成MCU并写入
{
yCounter = 1;//MCUIndex[SamplingType][0]; //按采样方式初始化各信号计数器
uCounter = 1;//MCUIndex[SamplingType][1];
vCounter = 1;//MCUIndex[SamplingType][2];
for (; i < yBufLen; i += DCTBLOCKSIZE)
{
for (j = 0; j < DCTBLOCKSIZE; j++)
{
dctYBuf[j] = FLOAT(lpYBuf[i + j] - 128);
}
if (yCounter > 0)
{
--yCounter;
ProcessDU(dctYBuf,YQT_DCT,STD_DC_Y_HT,STD_AC_Y_HT,&yDC);
}
else
{
break;
}
}
//------------------------------------------------------------------
for (; m < uBufLen; m += DCTBLOCKSIZE)
{
for (n = 0; n < DCTBLOCKSIZE; n++)
{
dctUBuf[n] = FLOAT(lpUBuf[m + n] - 128);
}
if (uCounter > 0)
{
--uCounter;
ProcessDU(dctUBuf,UVQT_DCT,STD_DC_UV_HT,STD_AC_UV_HT,&uDC);
}
else
{
break;
}
}
//-------------------------------------------------------------------
for (; s < vBufLen; s += DCTBLOCKSIZE)
{
for (k = 0; k < DCTBLOCKSIZE; k++)
{
dctVBuf[k] = FLOAT(lpVBuf[s + k] - 128);
}
if (vCounter > 0)
{
--vCounter;
ProcessDU(dctVBuf,UVQT_DCT,STD_DC_UV_HT,STD_AC_UV_HT,&vDC);
}
else
{
break;
}
}
}
}
// 8x8的浮点离散余弦变换
void FDCT(FLOAT* lpBuff)
{
FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
FLOAT tmp10, tmp11, tmp12, tmp13;
FLOAT z1, z2, z3, z4, z5, z11, z13;
FLOAT* dataptr;
int ctr;
/* 第一部分，对行进行计算 */
dataptr = lpBuff;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--)
{
tmp0 = dataptr[0] + dataptr[7];
tmp7 = dataptr[0] - dataptr[7];
tmp1 = dataptr[1] + dataptr[6];
tmp6 = dataptr[1] - dataptr[6];
tmp2 = dataptr[2] + dataptr[5];
tmp5 = dataptr[2] - dataptr[5];
tmp3 = dataptr[3] + dataptr[4];
tmp4 = dataptr[3] - dataptr[4];
/* 对偶数项进行运算 */
tmp10 = tmp0 + tmp3; /* phase 2 */
tmp13 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp1 - tmp2;
dataptr[0] = tmp10 + tmp11; /* phase 3 */
dataptr[4] = tmp10 - tmp11;
z1 = (tmp12 + tmp13) * (0.707106781); /* c4 */
dataptr[2] = tmp13 + z1; /* phase 5 */
dataptr[6] = tmp13 - z1;
/* 对奇数项进行计算 */
tmp10 = tmp4 + tmp5; /* phase 2 */
tmp11 = tmp5 + tmp6;
tmp12 = tmp6 + tmp7;
z5 = (tmp10 - tmp12) * ( 0.382683433); /* c6 */
z2 = (0.541196100) * tmp10 + z5; /* c2-c6 */
z4 = (1.306562965) * tmp12 + z5; /* c2+c6 */
z3 = tmp11 * (0.707106781); /* c4 */
z11 = tmp7 + z3; /* phase 5 */
z13 = tmp7 - z3;
dataptr[5] = z13 + z2; /* phase 6 */
dataptr[3] = z13 - z2;
dataptr[1] = z11 + z4;
dataptr[7] = z11 - z4;
dataptr += DCTSIZE; /* 将指针指向下一行 */
}
/* 第二部分，对列进行计算 */
dataptr = lpBuff;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--)
{
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
/* 对偶数项进行运算 */
tmp10 = tmp0 + tmp3; /* phase 2 */
tmp13 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp1 - tmp2;
dataptr[DCTSIZE*0] = tmp10 + tmp11; /* phase 3 */
dataptr[DCTSIZE*4] = tmp10 - tmp11;
z1 = (tmp12 + tmp13) * (0.707106781); /* c4 */
dataptr[DCTSIZE*2] = tmp13 + z1; /* phase 5 */
dataptr[DCTSIZE*6] = tmp13 - z1;
/* 对奇数项进行计算 */
tmp10 = tmp4 + tmp5; /* phase 2 */
tmp11 = tmp5 + tmp6;
tmp12 = tmp6 + tmp7;
z5 = (tmp10 - tmp12) * (0.382683433); /* c6 */
z2 = (0.541196100) * tmp10 + z5; /* c2-c6 */
z4 = (1.306562965) * tmp12 + z5; /* c2+c6 */
z3 = tmp11 * (0.707106781); /* c4 */
z11 = tmp7 + z3; /* phase 5 */
z13 = tmp7 - z3;
dataptr[DCTSIZE*5] = z13 + z2; /* phase 6 */
dataptr[DCTSIZE*3] = z13 - z2;
dataptr[DCTSIZE*1] = z11 + z4;
dataptr[DCTSIZE*7] = z11 - z4;
++dataptr; /* 将指针指向下一列 */
}
}
//********************************************************************
// 方法名称:WriteBits
//
// 方法说明:写入二进制流
//
// 参数说明:
// value:AC/DC信号的振幅
//********************************************************************
void WriteBits(HUFFCODE huffCode)
{
WriteBitsStream(huffCode.code,huffCode.length);
}
void WriteBits(SYM2 sym)
{
WriteBitsStream(sym.amplitude,sym.codeLen);
}
//********************************************************************
// 方法名称:WriteBitsStream
//
// 方法说明:写入二进制流
//
// 参数说明:
// value:需要写入的值
// codeLen:二进制长度
//********************************************************************
void WriteBitsStream(USHORT value,BYTE codeLen)
{
CHAR posval;//bit position in the bitstring we read, should be<=15 and >=0
posval=codeLen-1;
while (posval>=0)
{
if (value & mask[posval])
{
bytenew|=mask[bytepos];
}
posval--;bytepos--;
if (bytepos<0)
{
if (bytenew==0xFF)
{
WriteByte(0xFF);
WriteByte(0);
}
else
{
WriteByte(bytenew);
}
bytepos=7;bytenew=0;
}
}
}
//********************************************************************
// 方法名称:RLEComp
//
// 方法说明:使用RLE算法对AC压缩,假设输入数据1,0,0,0,3,0,5
// 输出为(0,1)(3,3)(1,5),左位表示右位数据前0的个数
// 左位用4bits表示,0的个数超过表示范围则输出为(15,0)
// 其余的0数据在下一个符号中表示.
//
// 参数说明:
// lpbuf:输入缓冲,8x8变换信号缓冲
// lpOutBuf:输出缓冲,结构数组,结构信息见头文件
// resultLen:输出缓冲长度,即编码后符号的数量
//********************************************************************
void RLEComp(SHORT* lpbuf,ACSYM* lpOutBuf,BYTE &resultLen)
{
BYTE zeroNum = 0; //0行程计数器
UINT EOBPos = 0; //EOB出现位置
const BYTE MAXZEROLEN = 15; //最大0行程
UINT i = 0; //临时变量
UINT j = 0;
EOBPos = DCTBLOCKSIZE - 1; //设置起始位置，从最后一个信号开始
for (i = EOBPos; i > 0; i--) //从最后的AC信号数0的个数
{
if (lpbuf[i] == 0) //判断数据是否为0
{
--EOBPos; //向前一位
}
else //遇到非0，跳出
{
break;
}
}
for (i = 1; i <= EOBPos; i++) //从第二个信号，即AC信号开始编码
{
if (lpbuf[i] == 0 && zeroNum < MAXZEROLEN) //如果信号为0并连续长度小于15
{
++zeroNum;
}
else
{
lpOutBuf[j].zeroLen = zeroNum; //0行程（连续长度）
lpOutBuf[j].codeLen = ComputeVLI(lpbuf[i]); //幅度编码长度
lpOutBuf[j].amplitude = lpbuf[i]; //振幅
zeroNum = 0; //0计数器复位
++resultLen; //符号数量++
++j; //符号计数
}
}
}
//********************************************************************
// 方法名称:BuildSym2
//
// 方法说明:将信号的振幅VLI编码,返回编码长度和信号振幅的反码
//
// 参数说明:
// value:AC/DC信号的振幅
//********************************************************************
SYM2 BuildSym2(SHORT value)
{
SYM2 Symbol;
Symbol.codeLen = ComputeVLI(value); //获取编码长度
Symbol.amplitude = 0;
if (value >= 0)
{
Symbol.amplitude = value;
}
else
{
Symbol.amplitude = SHORT(pow(2,Symbol.codeLen)-1) + value; //计算反码
}
return Symbol;
}
//返回符号的长度
BYTE ComputeVLI(SHORT val)
{
BYTE binStrLen = 0;
val = abs(val);
//获取二进制码长度
if(val == 1)
{
binStrLen = 1;
}
else if(val >= 2 && val <= 3)
{
binStrLen = 2;
}
else if(val >= 4 && val <= 7)
{
binStrLen = 3;
}
else if(val >= 8 && val <= 15)
{
binStrLen = 4;
}
else if(val >= 16 && val <= 31)
{
binStrLen = 5;
}
else if(val >= 32 && val <= 63)
{
binStrLen = 6;
}
else if(val >= 64 && val <= 127)
{
binStrLen = 7;
}
else if(val >= 128 && val <= 255)
{
binStrLen = 8;
}
else if(val >= 256 && val <= 511)
{
binStrLen = 9;
}
else if(val >= 512 && val <= 1023)
{
binStrLen = 10;
}
else if(val >= 1024 && val <= 2047)
{
binStrLen = 11;
}
return binStrLen;
}
//********************************************************************
// 方法名称:BuildVLITable
//
// 方法说明:生成VLI表
//
// 参数说明:
//********************************************************************
void BuildVLITable(void)
{
int i = 0;
for (i = 0; i < DC_MAX_QUANTED; ++i)
{
pVLITAB[i] = ComputeVLI(i);
}
for (i = DC_MIN_QUANTED; i < 0; ++i)
{
pVLITAB[i] = ComputeVLI(i);
}
}
};
#endif // __JENC__
Jpeg.h
typedef struct tagBMBUFINFO
{
UINT imgWidth;
UINT imgHeight;
UINT buffWidth;
UINT buffHeight;
WORD BitCount;
BYTE padSize;
}BMBUFINFO;
// DCT转换尺寸
static const BYTE DCTSIZE = 8;
// DCT转换块长度
static const BYTE DCTBLOCKSIZE = 64;
//Huffman码结构
typedef struct tagHUFFCODE
{
WORD code; // huffman 码字
BYTE length; // 编码长度
WORD val; // 码字对应的值
}HUFFCODE;
//AC信号中间符号结构
typedef struct tagACSYM
{
BYTE zeroLen; //0行程
BYTE codeLen; //幅度编码长度
SHORT amplitude;//振幅
}ACSYM;
//DC/AC 中间符号2描述结构
typedef struct tagSYM2
{
SHORT amplitude;//振幅
BYTE codeLen; //振幅长度(二进制形式的振幅数据的位数)
}SYM2;
// 存放VLI表
BYTE VLI_TAB[4096];
BYTE* pVLITAB; //VLI_TAB的别名,使下标在-2048-2048
// 存放2个量化表
BYTE YQT[DCTBLOCKSIZE];
BYTE UVQT[DCTBLOCKSIZE];
// 存放2个FDCT变换要求格式的量化表
FLOAT YQT_DCT[DCTBLOCKSIZE];
FLOAT UVQT_DCT[DCTBLOCKSIZE];
//存放4个Huffman表
HUFFCODE STD_DC_Y_HT[12];
HUFFCODE STD_DC_UV_HT[12];
HUFFCODE STD_AC_Y_HT[256];
HUFFCODE STD_AC_UV_HT[256];
static BYTE bytenew=0; // The byte that will be written in the JPG file
static CHAR bytepos=7; //bit position in the byte we write (bytenew)
//should be<=7 and >=0
static USHORT mask[16]={1,2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768};
static const DOUBLE aanScaleFactor[8] = {1.0, 1.387039845, 1.306562965, 1.175875602,
1.0, 0.785694958, 0.541196100, 0.275899379};
//量化后DC范围在-2^11 - 2^11 - 1之间,量化后AC范围在-2^10 - 2^10 - 1之间
static const INT AC_MAX_QUANTED = 1023; //量化后AC的最大值
static const INT AC_MIN_QUANTED = -1024; //量化后AC的最小值
static const INT DC_MAX_QUANTED = 2047; //量化后DC的最大值
static const INT DC_MIN_QUANTED = -2048; //量化后DC的最小值
//标准亮度信号量化模板
const static BYTE std_Y_QT[64] =
{
16, 11, 10, 16, 24, 40, 51, 61,
12, 12, 14, 19, 26, 58, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56,
14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68, 109,103,77,
24, 35, 55, 64, 81, 104,113,92,
49, 64, 78, 87, 103,121,120,101,
72, 92, 95, 98, 112,100,103,99
};
//标准色差信号量化模板
const static BYTE std_UV_QT[64] =
{
17, 18, 24, 47, 99, 99, 99, 99,
18, 21, 26, 66, 99, 99, 99, 99,
24, 26, 56, 99, 99, 99, 99, 99,
47, 66, 99 ,99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99
};
//正向 8x8 Z变换表
const static BYTE FZBT[64] =
{
0, 1, 5, 6, 14,15,27,28,
2, 4, 7, 13,16,26,29,42,
3, 8, 12,17,25,30,41,43,
9, 11,18,24,31,40,44,53,
10,19,23,32,39,45,52,54,
20,22,33,38,46,51,55,60,
21,34,37,47,50,56,59,61,
35,36,48,49,57,58,62,63
};
//色彩空间系数常量,依次是411,111,211采样的系数,211采样的2种方式的系数相同
static const FLOAT COLORSPACECOEF[4][3] = {{1,0.25,0.25},{1,1,1},{1,0.5,0.5},{1,0.5,0.5}};
//MCU中各型号分量出现的比率
static const BYTE MCUIndex[4][3] = {{4,1,1},{1,1,1},{2,1,1},{2,1,1}};
// 标准Huffman表 (cf. JPEG standard section K.3)
static BYTE STD_DC_Y_NRCODES[17]={0,0,1,5,1,1,1,1,1,1,0,0,0,0,0,0,0};
static BYTE STD_DC_Y_VALUES[12]={0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
static BYTE STD_DC_UV_NRCODES[17]={0,0,3,1,1,1,1,1,1,1,1,1,0,0,0,0,0};
static BYTE STD_DC_UV_VALUES[12]={0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
static BYTE STD_AC_Y_NRCODES[17]={0,0,2,1,3,3,2,4,3,5,5,4,4,0,0,1,0X7D };
static BYTE STD_AC_Y_VALUES[162]= {
0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa };
static BYTE STD_AC_UV_NRCODES[17]={0,0,2,1,2,4,4,3,4,7,5,4,4,0,1,2,0X77};
static BYTE STD_AC_UV_VALUES[162]={
0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa };
Jpegformat.h
//文件开始,开始标记为0xFFD8
const static WORD SOITAG = 0xD8FF;
//文件结束,结束标记为0xFFD9
const static WORD EOITAG = 0xD9FF;
//JFIF APP0段结构
#pragma pack(push,1)
typedef struct tagJPEGAPP0
{
WORD segmentTag; //APP0段标记，必须为FFE0
WORD length; //段长度，一般为16，如果没有缩略图
CHAR id[5]; //文件标记 "JFIF" + "\0"
WORD ver; //文件版本，一般为0101或0102
BYTE densityUnit; //密度单位，0=无单位 1=点数/英寸 2=点数/厘米
WORD densityX; //X轴方向密度,通常写1
WORD densityY; //Y轴方向密度,通常写1
BYTE thp; //缩略图水平像素数,写0
BYTE tvp; //缩略图垂直像素数,写0
}JPEGAPP0;// = {0xE0FF,16,'J','F','I','F',0,0x0101,0,1,1,0,0};
#pragma pack(pop)
//JFIF APPN段结构
#pragma pack(push,1)
typedef struct tagJPEGAPPN
{
WORD segmentTag; //APPn段标记，从FFE0 - FFEF n=0-F
WORD length; //段长度
}JPEGAPPN;
#pragma pack(pop)
//JFIF DQT段结构(8 bits 量化表)
#pragma pack(push,1)
typedef struct tagJPEGDQT_8BITS
{
WORD segmentTag; //DQT段标记，必须为0xFFDB
WORD length; //段长度,这里是0x4300
BYTE tableInfo; //量化表信息
BYTE table[64]; //量化表(8 bits)
}JPEGDQT_8BITS;
#pragma pack(pop)
//JFIF DQT段结构(8 bits 量化表)
#pragma pack(push,1)
typedef struct tagJPEGDQT_16BITS
{
WORD segmentTag; //DQT段标记，必须为0xFFDB
WORD length; //段长度，这里是0x8300
BYTE tableInfo; //量化表信息
WORD table[64]; //量化表(16 bits)
}JPEGDQT_16BITS;
#pragma pack(pop)
//JFIF SOF0段结构(真彩)，其余还有SOF1-SOFF
#pragma pack(push,1)
typedef struct tagJPEGSOF0_24BITS
{
WORD segmentTag; //SOF段标记，必须为0xFFC0
WORD length; //段长度，真彩图为17，灰度图为11
BYTE precision; //精度，每个信号分量所用的位数，基本系统为0x08
WORD height; //图像高度
WORD width; //图像宽度
BYTE sigNum; //信号数量，真彩JPEG应该为3，灰度为1
BYTE YID; //信号编号，亮度Y
BYTE HVY; //采样方式，0-3位是垂直采样，4-7位是水平采样
BYTE QTY; //对应量化表号
BYTE UID; //信号编号，色差U
BYTE HVU; //采样方式，0-3位是垂直采样，4-7位是水平采样
BYTE QTU; //对应量化表号
BYTE VID; //信号编号，色差V
BYTE HVV; //采样方式，0-3位是垂直采样，4-7位是水平采样
BYTE QTV; //对应量化表号
}JPEGSOF0_24BITS;// = {0xC0FF,0x0011,8,0,0,3,1,0x11,0,2,0x11,1,3,0x11,1};
#pragma pack(pop)
//JFIF SOF0段结构(灰度)，其余还有SOF1-SOFF
#pragma pack(push,1)
typedef struct tagJPEGSOF0_8BITS
{
WORD segmentTag; //SOF段标记，必须为0xFFC0
WORD length; //段长度，真彩图为17，灰度图为11
BYTE precision; //精度，每个信号分量所用的位数，基本系统为0x08
WORD height; //图像高度
WORD width; //图像宽度
BYTE sigNum; //信号数量，真彩JPEG应该为3，灰度为1
BYTE YID; //信号编号，亮度Y
BYTE HVY; //采样方式，0-3位是垂直采样，4-7位是水平采样
BYTE QTY; //对应量化表号
}JPEGSOF0_8BITS;// = {0xC0FF,0x000B,8,0,0,1,1,0x11,0};
#pragma pack(pop)
//JFIF DHT段结构
#pragma pack(push,1)
typedef struct tagJPEGDHT
{
WORD segmentTag; //DHT段标记，必须为0xFFC4
WORD length; //段长度
BYTE tableInfo; //表信息，基本系统中 bit0-3 为Huffman表的数量，bit4 为0指DC的Huffman表 为1指AC的Huffman表，bit5-7保留，必须为0
BYTE huffCode[16];//1-16位的Huffman码字的数量，分别存放在数组[1-16]中
//BYTE* huffVal; //依次存放各码字对应的值
}JPEGDHT;
#pragma pack(pop)
// JFIF SOS段结构（真彩）
#pragma pack(push,1)
typedef struct tagJPEGSOS_24BITS
{
WORD segmentTag; //SOS段标记，必须为0xFFDA
WORD length; //段长度，这里是12
BYTE sigNum; //信号分量数，真彩图为0x03,灰度图为0x01
BYTE YID; //亮度Y信号ID,这里是1
BYTE HTY; //Huffman表号，bit0-3为DC信号的表，bit4-7为AC信号的表
BYTE UID; //亮度Y信号ID,这里是2
BYTE HTU;
BYTE VID; //亮度Y信号ID,这里是3
BYTE HTV;
BYTE Ss; //基本系统中为0
BYTE Se; //基本系统中为63
BYTE Bf; //基本系统中为0
}JPEGSOS_24BITS;// = {0xDAFF,0x000C,3,1,0,2,0x11,3,0x11,0,0x3F,0};
#pragma pack(pop)
// JFIF SOS段结构（灰度）
#pragma pack(push,1)
typedef struct tagJPEGSOS_8BITS
{
WORD segmentTag; //SOS段标记，必须为0xFFDA
WORD length; //段长度，这里是8
BYTE sigNum; //信号分量数，真彩图为0x03,灰度图为0x01
BYTE YID; //亮度Y信号ID,这里是1
BYTE HTY; //Huffman表号，bit0-3为DC信号的表，bit4-7为AC信号的表
BYTE Ss; //基本系统中为0
BYTE Se; //基本系统中为63
BYTE Bf; //基本系统中为0
}JPEGSOS_8BITS;// = {0xDAFF,0x0008,1,1,0,0,0x3F,0};
#pragma pack(pop)
// JFIF COM段结构
#pragma pack(push,1)
typedef struct tagJPEGCOM
{
WORD segmentTag; //COM段标记，必须为0xFFFE
WORD length; //注释长度
}JPEGCOM;
#pragma pack(pop)
Main.cpp
#include <iostream>
#include "jenc.h"
using namespace std;
int main(int argc, char* argv[])
{
if (argc <= 1)
{
cout << "please input bmp filename." << endl;
return 0;
}
string fileName = string(argv[1]);
string outFile = fileName.substr(0,fileName.find_last_of('.'));
outFile = outFile + ".jpg";
JEnc enc;
enc.Invoke(fileName, outFile,100);
cout << outFile << endl;
getchar();
return 0;
}
