vs2015使用c++对图片与base64格式的相互转换程序

Question

程序过程：
1、首先将本地图片转化为base64格式；
2、再将base64格式的图片转化为图片格式；
3、使用opencv读取并展示此图片。
急用，拜托大家了！！！！

Answer 1

string INMSBase64::Encode(const unsigned char* Data,int DataByte)
{
//编码表
const char EncodeTable[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
//返回值
string strEncode;
unsigned char Tmp[4]={0};
int LineLength=0;
for(int i=0;i<(int)(DataByte / 3);i++)
{
Tmp[1] = *Data++;
Tmp[2] = *Data++;
Tmp[3] = *Data++;
strEncode+= EncodeTable[Tmp[1] >> 2];
strEncode+= EncodeTable[((Tmp[1] << 4) | (Tmp[2] >> 4)) & 0x3F];
strEncode+= EncodeTable[((Tmp[2] << 2) | (Tmp[3] >> 6)) & 0x3F];
strEncode+= EncodeTable[Tmp[3] & 0x3F];
// if(LineLength+=4,LineLength==76) {strEncode+="\r\n";LineLength=0;}
}
//对剩余数据进行编码
int Mod=DataByte % 3;
if(Mod==1)
{
Tmp[1] = *Data++;
strEncode+= EncodeTable[(Tmp[1] & 0xFC) >> 2];
strEncode+= EncodeTable[((Tmp[1] & 0x03) << 4)];
strEncode+= "==";
}
else if(Mod==2)
{
Tmp[1] = *Data++;
Tmp[2] = *Data++;
strEncode+= EncodeTable[(Tmp[1] & 0xFC) >> 2];
strEncode+= EncodeTable[((Tmp[1] & 0x03) << 4) | ((Tmp[2] & 0xF0) >> 4)];
strEncode+= EncodeTable[((Tmp[2] & 0x0F) << 2)];
strEncode+= "=";
}

return strEncode;

}

string INMSBase64::Decode(const char* Data,int DataByte,int& OutByte)
{
//解码表
const char DecodeTable[] =
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
62, // '+'
0, 0, 0,
63, // '/'
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // '0'-'9'
0, 0, 0, 0, 0, 0, 0,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 'A'-'Z'
0, 0, 0, 0, 0, 0,
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // 'a'-'z'
};
//返回值
string strDecode;
int nValue;
int i= 0;
while (i < DataByte)
{
if (*Data != '\r' && *Data!='\n')
{
nValue = DecodeTable[*Data++] << 18;
nValue += DecodeTable[*Data++] << 12;
strDecode+=(nValue & 0x00FF0000) >> 16;
OutByte++;
if (*Data != '=')
{
nValue += DecodeTable[*Data++] << 6;
strDecode+=(nValue & 0x0000FF00) >> 8;
OutByte++;
if (*Data != '=')
{
nValue += DecodeTable[*Data++];
strDecode+=nValue & 0x000000FF;
OutByte++;
}
}
i += 4;
}
else// 回车换行,跳过
{
Data++;
i++;
}
}
return strDecode;
}