對于文件比較復雜的時候，為了獲取文件中的信息，需要一些比較特殊的函數，比如，getline()、replace（）、atoi,atof等

例子一，讀取以下文件中的數據，并保存進一個類里面。

首先，類的定義如下，感覺是struct，但是按照struct的處理，我這段代碼出錯了，不知道什么問題，暫時po出來吧，有空看看。

struct ImageLabel{std::string imagePath;//save圖片路徑名int faceBox[4];//輸入點集的最外層包絡矩形rect四個參數int landmarkPos[2*LandmarkPointsNum];//輸入點集private:friend class cereal::access;/*** Serialises this class using cereal.** @param[in] ar The archive to serialise to (or to serialise from).*/template<class Archive>void serialize(Archive& ar){ar(imagePath, faceBox, landmarkPos);} };

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然后讀入一系列如下文件，每個文件的數據保存格式相同，因此定義了一個vector，來順序存儲每一個文件對應的類

文件如下：*.pts文件

version: 1 n_points: 68 { 446.000 91.000 449.459 119.344 450.957 150.614 460.552 176.986 471.486 202.157 488.087 226.842 506.016 246.438 524.662 263.865 553.315 271.435 578.732 266.260 599.361 248.966 615.947 220.651 627.439 197.999 635.375 179.064 642.063 156.371 647.302 124.753 646.518 92.944 470.271 117.870 486.218 109.415 503.097 114.454 519.714 120.090 533.680 127.609 571.937 123.590 585.702 117.155 602.344 109.070 620.077 103.951 633.964 111.236 554.931 145.072 554.589 161.106 554.658 177.570 554.777 194.295 532.717 197.930 543.637 202.841 555.652 205.483 565.441 202.069 576.368 197.061 487.474 136.436 499.184 132.337 513.781 133.589 527.594 143.047 513.422 144.769 499.117 144.737 579.876 140.815 590.901 130.008 605.648 128.376 618.343 132.671 606.771 140.525 593.466 141.419 519.040 229.040 536.292 221.978 }

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所有pts文件名都保存在一個TXT文件中，對應的圖像名也保存在一個TXT文件中，我們需要把圖片的文件路徑加文件名保存到類里面，為了處理方便我們用了replace函數，直接替換pts文件名的的后三位，得到新的文件名。

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void readpic(std::vector<ImageLabel> &Imagelabels){cout<<"test readpic"<<endl;string filePath = "/Users/anitafang/Downloads/Datasets/300W/300w/01_Indoor/";//打開png圖片名存儲的TXT文件 ifstream pngfile;pngfile.open("/Users/anitafang/Downloads/Datasets/300W/300w/01_Indoor/pnglist.txt");if(!pngfile.is_open()){cout<<"不能打開文件!"<<endl;}//ImageLabel* mImageLabel = NULL;//保存圖像信息的類string line;//讀取文件的每一行while(getline(pngfile,line)){//mImageLabel = new ImageLabel(); ImageLabel mImageLabel;//mImageLabel->imagePath=filePath+line;//將文件全路徑保存在 mImageLabel->imagePathmImageLabel.imagePath=filePath+line;//將文件全路徑保存在 mImageLabel->imagePathcout<<line<<endl;//得到pts文件路徑string ress="pts";string ptss=filePath+line.replace(11,3,ress);cout<<line.replace(11,3,ress)<<endl;cout<<ptss<<endl;//讀取pts文件里面的數據std::ifstream LabelsFile(ptss, std::ios::in);if(!LabelsFile.is_open())return;//開始讀取pts文件內容int index=0;vector<Point2f> vp2f;char line11[1024]={0};//存放每行數據//將文件逐行讀取到string linestr中，然后對行的內容進行判斷while(LabelsFile.getline(line11, sizeof(line11))){//從第四行開始把數據寫進landmark數組中if((index>=3)&&(index<139)){string x = "";string y = "";std::stringstream word(line11);word >> x;word >> y;cout<<atof(x.c_str())<<" "<<atof(y.c_str())<<endl;mImageLabel.landmarkPos[index-3] =atof(x.c_str());mImageLabel.landmarkPos[index+LandmarkPointsNum-3] =atof(y.c_str());vp2f.push_back(Point2f(mImageLabel.landmarkPos[index-3],mImageLabel.landmarkPos[index+LandmarkPointsNum-3]));cout<<"x:"<<mImageLabel.landmarkPos[index-3]<<" y:"<<mImageLabel.landmarkPos[index+LandmarkPointsNum-3]<<endl;}index++;}Rect rect = boundingRect(vp2f);//根據得到的矩形 輸入到facebox中mImageLabel.faceBox[0] = rect.x;mImageLabel.faceBox[1] = rect.y;mImageLabel.faceBox[2] = rect.width;mImageLabel.faceBox[3] = rect.height;cout<<"facebox"<<mImageLabel.faceBox[0]<<mImageLabel.faceBox[1]<<mImageLabel.faceBox[2]<<mImageLabel.faceBox[3]<<endl;// close file LabelsFile.close();//free the object Imagelabels.push_back(mImageLabel);//mImageLabel == NULL; } }

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其中，因為GetLine讀出來的數據是string類型，因此需要將數據轉成int型，看到pts文件中數據是都是float型，因此先要將string轉成float，用的是atof函數。

另外如果把?Imagelabels 當做類來處理只需要，最開始，ImageLabel mImageLabel;后面直接push_back，不需要delete。所有的引用都變成：mImageLabel.faceBox，不能用mImageLabel->landmarkPos。

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另外一個升級的例子，處理起來很復雜，這里把ImageLabel當做一個struct來處理，這樣需要new，也需要delete,引用的時候也是用的->，這個需要注意。

文件是：labels_ibug_300W.xml

稍微看一部分，了解下它的構成。

<?xml version='1.0' encoding='ISO-8859-1'?> <?xml-stylesheet type='text/xsl' href='image_metadata_stylesheet.xsl'?> <dataset> <name>iBUG face point dataset - All images</name> <comment>This folder contains data downloaded from: http://ibug.doc.ic.ac.uk/resources/facial-point-annotations/ The dataset is actually a combination of the AFW, HELEN, iBUG, and LFPW face landmark datasets. But the iBUG people have aggregated it all together and gave them a consistent set of 68 landmarks across all the images, thereby turning it into one big dataset.Note that we have adjusted the coordinates of the points from the MATLAB convention of 1 being the first index to 0 being the first index. So the coordinates in this file are in the normal C 0-indexed coordinate system.We have also added left right flips (i.e. mirrors) of each image and also appropriately flipped the landmarks. This doubles the size of the dataset. Each of the mirrored versions of the images has a filename that ends with _mirror.jpg.Finally, note that the bounding boxes are from dlib's default face detector. For the faces the detector failed to detect, we guessed at what the bounding box would have been had the detector found it and used that.</comment> <images><image file='afw/1051618982_1.jpg'><box top='206' left='469' width='216' height='216'><part name='00' x='482' y='267'/><part name='01' x='483' y='298'/><part name='02' x='487' y='329'/><part name='03' x='491' y='358'/><part name='04' x='503' y='386'/><part name='05' x='523' y='409'/><part name='06' x='543' y='428'/><part name='07' x='565' y='442'/><part name='08' x='591' y='447'/><part name='09' x='620' y='443'/><part name='10' x='647' y='429'/><part name='11' x='671' y='409'/><part name='12' x='688' y='385'/><part name='13' x='699' y='359'/><part name='14' x='704' y='332'/><part name='15' x='707' y='305'/><part name='16' x='708' y='277'/><part name='17' x='502' y='250'/><part name='18' x='518' y='237'/><part name='19' x='537' y='234'/><part name='20' x='557' y='236'/><part name='21' x='575' y='243'/><part name='22' x='619' y='243'/><part name='23' x='639' y='237'/><part name='24' x='659' y='234'/><part name='25' x='679' y='238'/><part name='26' x='693' y='250'/><part name='27' x='596' y='268'/><part name='28' x='595' y='287'/><part name='29' x='594' y='305'/><part name='30' x='593' y='324'/><part name='31' x='570' y='336'/><part name='32' x='581' y='338'/><part name='33' x='593' y='342'/><part name='34' x='605' y='338'/><part name='35' x='615' y='336'/><part name='36' x='523' y='272'/><part name='37' x='536' y='263'/><part name='38' x='551' y='263'/><part name='39' x='564' y='277'/><part name='40' x='550' y='277'/><part name='41' x='535' y='276'/><part name='42' x='626' y='279'/><part name='43' x='642' y='265'/><part name='44' x='657' y='267'/><part name='45' x='670' y='276'/><part name='46' x='658' y='280'/><part name='47' x='642' y='279'/><part name='48' x='544' y='364'/><part name='49' x='565' y='360'/><part name='50' x='580' y='357'/><part name='51' x='591' y='360'/><part name='52' x='603' y='358'/><part name='53' x='621' y='361'/><part name='54' x='641' y='366'/><part name='55' x='621' y='382'/><part name='56' x='603' y='385'/><part name='57' x='590' y='384'/><part name='58' x='579' y='383'/><part name='59' x='563' y='378'/><part name='60' x='552' y='366'/><part name='61' x='580' y='370'/><part name='62' x='591' y='370'/><part name='63' x='603' y='371'/><part name='64' x='634' y='369'/><part name='65' x='603' y='371'/><part name='66' x='591' y='370'/><part name='67' x='580' y='370'/></box></image><image file='afw/111076519_1.jpg'><box top='724' left='1122' width='150' height='150'><part name='00' x='1126' y='765'/><part name='01' x='1123' y='784'/><part name='02' x='1123' y='804'/><part name='03' x='1124' y='822'/><part name='04' x='1131' y='839'/><part name='05' x='1142' y='853'/><part name='06' x='1157' y='865'/><part name='07' x='1172' y='874'/><part name='08' x='1190' y='878'/><part name='09' x='1208' y='878'/><part name='10' x='1225' y='873'/><part name='11' x='1238' y='862'/><part name='12' x='1249' y='846'/><part name='13' x='1256' y='829'/><part name='14' x='1261' y='810'/><part name='15' x='1263' y='792'/><part name='16' x='1264' y='774'/><part name='17' x='1148' y='749'/><part name='18' x='1160' y='745'/><part name='19' x='1171' y='744'/><part name='20' x='1183' y='748'/><part name='21' x='1194' y='753'/><part name='22' x='1227' y='756'/><part name='23' x='1236' y='753'/><part name='24' x='1244' y='753'/><part name='25' x='1251' y='754'/><part name='26' x='1256' y='759'/><part name='27' x='1210' y='769'/><part name='28' x='1210' y='779'/><part name='29' x='1210' y='790'/><part name='30' x='1209' y='800'/><part name='31' x='1187' y='808'/><part name='32' x='1196' y='811'/><part name='33' x='1205' y='814'/><part name='34' x='1212' y='813'/><part name='35' x='1218' y='812'/><part name='36' x='1159' y='766'/><part name='37' x='1167' y='763'/><part name='38' x='1176' y='764'/><part name='39' x='1183' y='770'/><part name='40' x='1175' y='770'/><part name='41' x='1166' y='769'/><part name='42' x='1225' y='776'/><part name='43' x='1235' y='773'/><part name='44' x='1243' y='774'/><part name='45' x='1248' y='777'/><part name='46' x='1241' y='779'/><part name='47' x='1233' y='779'/><part name='48' x='1160' y='825'/><part name='49' x='1176' y='820'/><part name='50' x='1190' y='822'/><part name='51' x='1199' y='824'/><part name='52' x='1209' y='825'/><part name='53' x='1221' y='827'/><part name='54' x='1229' y='833'/><part name='55' x='1218' y='847'/><part name='56' x='1205' y='852'/><part name='57' x='1194' y='851'/><part name='58' x='1184' y='849'/><part name='59' x='1171' y='840'/><part name='60' x='1165' y='827'/><part name='61' x='1189' y='828'/><part name='62' x='1199' y='830'/><part name='63' x='1208' y='831'/><part name='64' x='1225' y='834'/><part name='65' x='1206' y='844'/><part name='66' x='1196' y='844'/><part name='67' x='1186' y='841'/></box></image><image file='afw/111076519_2.jpg'><box top='590' left='1028' width='180' height='180'><part name='00' x='1050' y='620'/><part name='01' x='1046' y='641'/><part name='02' x='1040' y='663'/>

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可以找到一些規律，按照這些規律來得到我們需要的數據，直接上代碼：

void ReadLabelsFromFile(std::vector<ImageLabel> &Imagelabels, std::string Path = "labels_ibug_300W.xml"){std::string ParentPath(trainFilePath);std::ifstream LabelsFile(ParentPath+Path, std::ios::in);if(!LabelsFile.is_open())return;std::string linestr;while(std::getline(LabelsFile, linestr)){linestr = trim(linestr);linestr = replace(linestr, "</", "");linestr = replace(linestr, "/>", "");linestr = replace(linestr, "<", "");linestr = replace(linestr, ">", "");linestr = replace(linestr, "'", "");std::vector<std::string> strNodes = split(linestr, " ");static ImageLabel* mImageLabel = NULL;switch (strNodes.size()) {case 1:if(strNodes[0] == "image"){Imagelabels.push_back(*mImageLabel);delete mImageLabel;}break;case 2:if(strNodes[0] == "image"){mImageLabel = new ImageLabel();mImageLabel->imagePath = ParentPath + split(strNodes[1], "=")[1]; // std::cout << mImageLabel->imagePath << std::endl; // cv::Mat Image = cv::imread(mImageLabel->imagePath); // cv::imshow("Image", Image); // cv::waitKey(0);}break;case 5:if(strNodes[0] == "box"){mImageLabel->faceBox[0] = atoi(split(strNodes[1], "=")[1].data());mImageLabel->faceBox[1] = atoi(split(strNodes[2], "=")[1].data());mImageLabel->faceBox[2] = atoi(split(strNodes[3], "=")[1].data());mImageLabel->faceBox[3] = atoi(split(strNodes[4], "=")[1].data());}break;case 4:if(strNodes[0] == "part"){int index = atoi(split(strNodes[1], "=")[1].data());mImageLabel->landmarkPos[index] = atoi(split(strNodes[2], "=")[1].data());mImageLabel->landmarkPos[index+LandmarkPointsNum] = atoi(split(strNodes[3], "=")[1].data());}break;default:break;}}LabelsFile.close(); }

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轉載于:https://www.cnblogs.com/Anita9002/p/7122290.html

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