21 and 22

README.md

@@ -20,7 +20,7 @@ In progress June 30, 2017
 * ~~Chapter 22~~
 
 Checking Chapters
-~~2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,~~ 14, 15 16 17 18 19 20 21 22 23
+~~2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,~~ 14, 15 16 17 18 19 20 ~~21 22 23~~
 
 * Submit associated errata for ~~15 16~~ 17 18 19 20 21 22
 * Throw in some bonus material

example_21-01.cpp

@@ -1,3 +1,5 @@
+//Example 21-1. Creating and training a decision tree
+
 #include <opencv2/opencv.hpp>
 #include <stdio.h>
 #include <iostream>
@@ -12,6 +14,7 @@ void help(char **argv) {
        << "    This program demonstrates how to create and a train a \n"
        << "    decision tree using ml library in OpenCV.\n"
        << "Call:\n" << argv[0] << " <csv-file-path>\n\n"
+       << "\nIf you don't enter a file, it defaults to ../mushroom/agaricus-lepiota.data\n"
        << endl;
 }
 

example_22-01.cpp

@@ -18,7 +18,7 @@ using std::string;
 //
 void detectAndDraw(
         cv::Mat& img,                               // input image
-        cv::Ptr<cv::CascadeClassifier> classifier,  // preloaded classifier
+         cv::Ptr<cv::CascadeClassifier> classifier,  // preloaded classifier
         double scale = 1.3) {                       // resize image by ...
     // Just some pretty colors to draw with
     //
@@ -50,7 +50,6 @@ void detectAndDraw(
 
     // Loop through to found objects and draw boxes around them
     //
-
     int i = 0;
     for (vector<cv::Rect>::iterator r = objects.begin();
             r != objects.end(); r++, ++i) {
@@ -69,23 +68,20 @@ int main(int argc, char** argv) {
     //   - path to .xml classifier file
     //
     if (argc < 3) {
-        cerr << "Error: wrong number of arguments.\n";
-        cerr << "Use:\n" << argv[0] << " <image_file> <xml_classifier_file>\n"
-             << "to run this demo\n\n"
-             << "Example:\n"
-             << argv[0] << " faces.png haarcascade_frontalface_alt.xml\n"
-             << std::endl;
+        cerr << "\nError: wrong number of arguments.\n";
+        cerr 	<< "\nExample 22-1. Detecting and drawing faces\n\n"
+				<< "Use:\n" << argv[0] << " <path/image_file> <path/xml_classifier_file>\n"
+				<< "to run this demo\n\n"
+				<< "Example:\n"
+				<< argv[0] << " ../faces.png ../haarcascade_frontalface_alt.xml\n"
+				<< std::endl;
         exit(1);
     }
-
     string image_file_name = string(argv[1]);
     cv::Mat img = cv::imread(image_file_name, CV_LOAD_IMAGE_COLOR);
-
     string cascade_file_name = string(argv[2]);
     cv::Ptr<cv::CascadeClassifier> cascade(new cv::CascadeClassifier(cascade_file_name));
-
     detectAndDraw(img, cascade);
-
     cv::imshow("Result", img);
     cv::waitKey(0);