1 CxImage的作用
CxImage将几张图片合成一张图片，在一张底图上添加图片，有些图片是有透明效果的，实现图片之间的透明重叠效果。另外还可以添加文字。
（1）背景图片mymix.png
（2）角标图片，左下角为透明的，black.png和snap.png
(3)字图片1MixImage1.jpg和MixImage2.jpg
（4）合成后图片效果图
现在的目标就是将（2），（3）中的有透明的图片和不透明的图片合成到背景图片（1）上，实现图片（4）中的效果。
1 CxImage合成实例
CxImage imageMix;//合成后的图片
CxImage imagesy1;//子图片1
CxImage imagesy2;//字图片2
CxImage imagesysnapfalg1;//透明图片1
CxImage imagesyblackflag2;//透明图片2
CxImage::CXTEXTINFO BlackName, BlackSex, UserCardId, CompareSimilarity, SnapPicTime, CaseDescrip;//图片叠加文字
imagesy1.load("MixImage1.jpg", CXIMAGE_FORMAT_JPG);//加载子图片1
imagesy2. Load ("MixImage2.jpg", CXIMAGE_FORMAT_JPG);//加载字图片2
imagesy1.Resample(340, 340, 0, &imagesy1);//设置子图片大小
imagesy2.Resample(340, 340, 0, &imagesy2);
//加载背景图片
if (imageMix.Load(_T("mymix.png"), CXIMAGE_FORMAT_JPG))
{ //将两张子图片合成到背景图片上
imageMix.MixFrom(imagesy2, 35, 398);//图片相对左下角，文字相对左上角
imageMix.MixFrom(imagesy1, 35, 28);//加入第一张子图片
//将带有一半透明的图片合成到背景上
imagesysnapfalg1.Load(_T("snap.png"),CXIMAGE_FORMAT_JPG);
imagesysnapfalg1.Resample(78,78,0,&imagesysnapfalg1);
imagesysnapfalg1.SetTransIndex(255);//设置图片的透明度0不透明，255完全透明
imageMix.MixFrom(imagesysnapfalg1,297,398+261);
//将带有一半透明的图片合成到背景上
imagesyblackflag2.Load(_T("black.png"),CXIMAGE_FORMAT_JPG);
imagesyblackflag2.Resample(78,78,0,&imagesyblackflag2);
imagesyblackflag2.SetTransIndex(255);
imageMix.MixFrom(imagesyblackflag2,297,290);
//初始化叠加文字结构体
imageMix.InitTextInfo(&BlackName);
imageMix.InitTextInfo(&BlackSex);
imageMix.InitTextInfo(&UserCardId);
imageMix.InitTextInfo(&CompareSimilarity);
imageMix.InitTextInfo(&SnapPicTime);
imageMix.InitTextInfo(&CaseDescrip);
//设置文字的属性
_stprintf(BlackName.lfont.lfFaceName, _T("微软雅黑"));//字体
BlackName.lfont.lfCharSet = GB2312_CHARSET;//字符集
BlackName.lfont.lfHeight = 40;//高度
BlackName.fcolor = RGB(255, 255, 255);//颜色
BlackName.opaque = 0;
_stprintf(BlackSex.lfont.lfFaceName, _T("微软雅黑"));
BlackSex.lfont.lfCharSet = GB2312_CHARSET;
BlackSex.lfont.lfHeight = 40;
BlackSex.fcolor = RGB(255, 255, 255);
BlackSex.opaque = 0;
_stprintf(UserCardId.lfont.lfFaceName, _T("微软雅黑"));
UserCardId.lfont.lfCharSet = GB2312_CHARSET;
UserCardId.lfont.lfHeight = 40;
UserCardId.fcolor = RGB(255, 255, 255);
UserCardId.opaque = 0;
_stprintf(CompareSimilarity.lfont.lfFaceName, _T("微软雅黑"));
CompareSimilarity.lfont.lfCharSet = GB2312_CHARSET;
CompareSimilarity.lfont.lfHeight = 40;
CompareSimilarity.fcolor = RGB(255, 255, 255);
CompareSimilarity.opaque = 0;
_stprintf(SnapPicTime.lfont.lfFaceName, _T("微软雅黑"));
SnapPicTime.lfont.lfCharSet = GB2312_CHARSET;
SnapPicTime.lfont.lfHeight = 40;
SnapPicTime.fcolor = RGB(255, 255, 255);
SnapPicTime.opaque = 0;
_stprintf(CaseDescrip.lfont.lfFaceName, _T("微软雅黑"));
CaseDescrip.lfont.lfCharSet = GB2312_CHARSET;
CaseDescrip.lfont.lfHeight = 40;
CaseDescrip.fcolor = RGB(255, 255, 255);
CaseDescrip.opaque = 0; //背景
//从结构体中输入文字的值
float similarity = sFasData.fSimilarity * 100;
sprintf_s(UserCardId.text, "%s", sFasData.strBlackCerNo.c_str());
sprintf_s(SnapPicTime.text, "%s", sFasData.strSnapTime.c_str());
sprintf_s(CompareSimilarity.text, "%0.*f", 2, similarity);
sprintf_s(BlackName.text,"%s",sFasData.strBlackName.c_str());
std::string strCaseDescrip = "未知";
//开始将文字叠加到图片
imageMix.DrawStringEx(0, 710, 138, &SnapPicTime);
imageMix.DrawStringEx(0, 679, 198, &CompareSimilarity);
imageMix.DrawStringEx(0, 519, 518, &BlackName);
imageMix.DrawStringEx(0, 509, 574, &BlackSex);
imageMix.DrawStringEx(0, 690, 638, &UserCardId);
}