听说Dlib这玩意有人脸识别，觉得好高大上。
然后想拿例子来玩玩，发现运行的时候悲剧了，提示说不支持jpeg。
开始查找原因，发现是没有定义宏DLIB_JPEG_SUPPORT（png一样）
需要在工程项目追加QMAKE_CXXFLAGS += -DDLIB_JPEG_SUPPORT（本质是makefile加宏）
编译的时候悲催了！！！
报各种jpeg*函数 undefined reference to。一开始的想法是追加libjpeg.lib静态库，发现需要VS2010.
但电脑没装，这玩意太大了。后来想下载dll或者编译好的lib。最后各种折腾，都不成功。
其实是我逗逼了，人家Dlib已经提供了jpeg的源码，加上去就可以了。。。
目录在E:\Dlib\dlib-19.4\dlib\external\libjpeg（png一样）。
把这个目录加上去就可以了（原谅我偷懒）
代码的话，用人家的例子
E:\Dlib\dlib-19.4\examples\face_detection_ex.cpp
1#include <dlib/image_processing/frontal_face_detector.h> 2#include <dlib/gui_widgets.h> 3#include <dlib/image_io.h> 4#include <iostream> 5 6using namespace dlib; 7using namespace std; 8 9int main(int argc, char** argv) 10{ 11 try 12 { 13 if (argc == 1) 14 { 15 cout << "Give some image files as arguments to this program." << endl; 16 return 0; 17 } 18 19 frontal_face_detector detector = get_frontal_face_detector(); 20 image_window win; 21 22 // Loop over all the images provided on the command line. 23 for (int i = 1; i < argc; ++i) 24 { 25 cout << "processing image " << argv[i] << endl; 26 array2d<unsigned char> img; 27 load_image(img, argv[i]); 28 // Make the image bigger by a factor of two. This is useful since 29 // the face detector looks for faces that are about 80 by 80 pixels 30 // or larger. Therefore, if you want to find faces that are smaller 31 // than that then you need to upsample the image as we do here by 32 // calling pyramid_up(). So this will allow it to detect faces that 33 // are at least 40 by 40 pixels in size. We could call pyramid_up() 34 // again to find even smaller faces, but note that every time we 35 // upsample the image we make the detector run slower since it must 36 // process a larger image. 37 pyramid_up(img); 38 39 // Now tell the face detector to give us a list of bounding boxes 40 // around all the faces it can find in the image. 41 std::vector<rectangle> dets = detector(img); 42 43 cout << "Number of faces detected: " << dets.size() << endl; 44 // Now we show the image on the screen and the face detections as 45 // red overlay boxes. 46 win.clear_overlay(); 47 win.set_image(img); 48 win.add_overlay(dets, rgb_pixel(255,0,0)); 49 50 cout << "Hit enter to process the next image..." << endl; 51 cin.get(); 52 } 53 } 54 catch (exception& e) 55 { 56 cout << "\nexception thrown!" << endl; 57 cout << e.what() << endl; 58 } 59}
在生成的二进制目录下运行*.exe *.jpg
我的是
D:\Qt\project\build-face_recognition-Desktop_Qt_5_5_0_MinGW_32bit-Debug\debug>fa
ce_recognition.exe E:\Dlib\dlib-19.4\examples\faces\2007_007763.jpg
运行结果如下：
