Programming Articles - Page 1346 of 3366

After writing the code, we need to run the code to execute and obtain the output. On running the program, we can check whether the code is written is correct and produces the desired output.Running a python program is quite an easy task.Run on IDLETo run a python program on IDLE, follow the given steps −Write the python code and save it.To run the program, go to Run > Run Module or simply click F5.Run on Command LineThe python script file is saved with ‘.py’ extension. After saving the python script, we can run it from the Command Line. In ... Read More

Python has no in-built function to reverse a string. Thus, we need to implement our own logic to reverse a string.We will reverse a string using different methods.Using FOR LoopThe idea behind this method is to use a reverse loop starting from the last index of the string to the 0th index. At each iteration, we will be adding characters of the string to hold the reversed string at the end of the iterations.Let’s look on the general procedure we will be following −a:=new stringloop from last index of string to 0th index and decrement by 1 a=a+character at the ... Read More

Python is a widely used high-level programming language. To write and execute code in python, we first need to install Python on our system.Installing Python on Windows takes a series of few easy steps.Step 1 − Select Version of Python to InstallPython has various versions available with differences between the syntax and working of different versions of the language. We need to choose the version which we want to use or need. There are different versions of Python 2 and Python 3 available.Step 2 − Download Python Executable InstallerOn the web browser, in the official site of python (www.python.org), move ... Read More

Here, we will learn how to detect and track the motion of eyeball in OpenCV.The following program demonstrates to detect the eyeball and track the location.Example#include #include #include #include #include #include using namespace cv; using namespace std; Vec3f eyeBallDetection(Mat& eye, vector& circles) {    vectorsums(circles.size(), 0);    for (int y = 0; y < eye.rows; y++) {       uchar* data = eye.ptr(y);       for (int x = 0; x < eye.cols; x++) {          int pixel_value = static_cast(*data);          for (int i = 0; i < circles.size(); i++) {   ... Read More

Here, we will learn how to track the eye in OpenCV. After detective the eyes, the tracking is an effortless and straightforward task. We used the circle to enclose the detected eyes. Tracking the center of the circle means tracking the center of eyes. To track the center of the circle, we need two integer variables. This has been done on the first two lines (9th and 10th line) inside the main() function. The name of the integer variables is 'x_axis' and 'y_axis'.In line 42 and 43, the horizontal and vertical coordinate values of the center have been copied to ... Read More

Here, we will learn how to detect the eye in OpenCV. We will use haarcascade_eye.xml classifier located in 'C:/opencv/sources/data/haarcascades' to detect the eyes. To detect the eyes, we need to add these headers.The first header is , and it is the header of C++ programming language. Reading writing images and user interface functionalities are defined in 'highgui' header. We need to add 'imgproc' header to enhance image quality, and we also use 'objdetect' header to detect face and eyes.The following program to demonstrate how to detect and track eye in OpenCV.Example#include #include #include #include using namespace cv; using namespace std; ... Read More

We will learn how to track the face in real-time in OpenCV. This program is same to the previous program and difference is that we used ellipse instead of rectangle to identify the face and we also used additional 'cout' statement to show the co-ordinate of the face in the console window.The following program to detect human face in real-time −Example#include #include #include //This header includes definition of 'rectangle()' function// #include //This header includes the definition of Cascade Classifier// #include using namespace std; using namespace cv; int main(int argc, char** argv) {    Mat video_stream;//Declaring a matrix hold frames from ... Read More

Detecting face in real-time is similar to detecting a face in still pictures.  The only difference is in real-time face detection, and we have to take a video stream of computer. In this program, we used 'VideoCapture()' function. This function captures video from other camera and stores the frames temporarily in matrix assigned to it. Here this function captures video from the default camera and temporarily stores the frames in 'real_time' matrix.The following program detects human faces in real-time −Example#include #include #include //This header includes definition of 'rectangle()' function// #include //This header includes the definition of Cascade Classifier// #include using ... Read More

When we want to track the position of the face, it is better to enclose the face with ellipse because an ellipse has a center. This center is also the center point of the detected face. As result, tracking the position of detected face becomes more accurate.The following program tracks the center of detected face and show the position in console window −Example#include #include #include //This header includes definition of 'rectangle()' function// #include //This header includes the definition of Cascade Classifier// #include using namespace std; using namespace cv; int main(int argc, char** argv){    Mat image_with_humanface;//Declaring a matrix to load ... Read More

We will learn how to detect the largest face only. This topic is same as the previous topic. The only difference is we used an additional 'Rect' structure and a 'for loop' to detect the largest face.The actual format of this function −Mat faceROI = image_with_humanface(maxRect)The maxRect have the area and location information of the largest face located on the image. The line above is cropping the same area stored in maxRect on the same location where the largest face is located on the image and storing in 'faceROI' matrix.The following program detects the largest face from still pictures −Example#include ... Read More