TIPS & TRICKS BLOG

In this article, I will be discussing how you can create a dialog from service. As we all know that service in android does not have any UI and it is intended for long-running background tasks. But sometimes it is required to show some information to the user when your app is running in the background. Today I will show you how you can implement this type of functionality in your application. Before starting the tutorial let me tell you about the special permission that we are going to use. Permission AndroidManifest.xml<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/> This permission allows the app to use the system level window. AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.app.dialogfromservice"> <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/> <appl

Today , I will show you how easily we can create a root checker app in android. It only takes 10 minutes to create this kind of application. activity_main.xml <?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <TextView android:id="@+id/textView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="60dp" android:text="This app checks the rooting status of your phone" android:textAlignment="center" android:textSize="18sp&q

Today, In this article we are going to learn how to “ Reset MySQL Root Password “. It is a good option to use this method only for resetting the password but it is highly insecure. So make sure after resetting the password, you also revert the changes from my.cnf file. Note: For Centos and Fedora Based OS sudo service mysqld stop sudo service mysqld start For Debian and Ubuntu OS sudo service mysql stop sudo service mysql start Steps Here i am using amazon linux 2 OS (based on centos) Stop mysql service – sudo service mysqld stop Open /etc/my.cnf file – sudo nano /etc/my.cnf Add skip-grant-tables under [mysqld] section Start MySql Service – sudo service mysqld start Open terminal and type mysql and type following query and press enter UPDATE mysql.user SET authentication_string=PASSWORD(‘Your new password’) WHERE User=’root’; Then write FLUSH PRIVILEGES; and press enter Now type – exit; Stop mysql service again – sudo service mysqld stop Open my.cnf file – sudo nano /etc/my.cnf

Today in this article “ Restore MySQL Database Without SQL Dump ” we will discuss how you can restore your database when you don’t have SQL dump file. This happens when your MYSQL gets corrupted. In that case, if you want to make a back up of your database you can simply copy following files and then restore them after a fresh installation Let’s Start Generally MySQL gets installed on following location /var/lib/mysql On this location it create folders of your databases. For instance, if you have databases like test, test1, test2 Then on this location /var/lib/mysql – You will have three folders test, test1, test2. And each of these folders will contain database files for the MyISAM database. It will have three main files with the following extensions frm myi myd And another three files which will be inside in /var/lib/mysql. These files are for INNO DB database. ibdata1 ib_logfile0 ib_logfile1 Steps: Stop Mysql Service using – sudo service mysqld stop Copy folder to /var/lib/mysql

Recently one of my friend came to me with a problem. He is looking out for new job but he feels quite boring to update  his profile on daily basis. As some people says updating profile in the morning gives you more calls as it keeps the newly updated profile on top (Although i don’t know whether naukri works this way or not 😀 ). As i was more interested to solve his problem.  After listening his problem i came to solution that instead of updating it manually lets make this job automatic. And it is quite interesting how we can automate our daily boring task with automation. Another day i came with the solution . And the solution was to make it automatic using selenium (Those who are not aware about selenium do check this link) In short, Selenium is a Testing automation Framework. And it is for automating web applications for testing purposes, but is certainly not limited to just that. Boring web-based administration tasks can (and should) also be automated as well. Then i started figu

Hello Guys, In this tutorial, I will discuss the color map in OpenCV. Color Map is used to show different color temperatures. And this can also be used to generate some cool image filters.  OpenCV comes with thirteen built-in color maps. So in this tutorial, I will show you how to use color maps.  Let’s get started List of Color Maps COLORMAP_AUTUMN COLORMAP_BONE COLORMAP_JET COLORMAP_WINTER COLORMAP_RAINBOW COLORMAP_OCEAN COLORMAP_SUMMER COLORMAP_SPRING COLORMAP_COOL COLORMAP_HSV COLORMAP_PINK COLORMAP_HOT COLORMAP_PARULA To apply color map first we need to convert an image to grayscale. So I will use  img = cv.imread("nature.jpg",cv.IMREAD_GRAYSCALE) If you are not aware of this function then please check my previous tutorial  http://techievaibhav.in/2019/01/10/reading-an-image-using-opencv/ To apply color maps, OpenCV comes with a function called applyColorMap() . This function takes two parameters. Gray Scale image Color Map Autumn Bone Cool Hot HSV Jet Ocean Parula Pink

In this tutorial, I will show you how to draw a circle in OpenCV. OpenCV comes with lots of built-in functions that make our life easier especially when we are working on image processing .  And there is a function called circle in OpenCV which is used to draw a circle. This function takes following parameters: 1. Image : Takes an image object 2. Center : Center point coordinates 3. Radius : Radius of the circle 4. Color : Takes color in BGR format 5. Thickness : By default set to 1 (optional) 6. Line Type : By default set to 8-connected.It can also be  LINE_AA  or  4-connected  (Optional) 7. Shift:  Shifts fractional bits in the point coordinates of center and radius (Optional) Especially when we are creating closed shapes. Thickness plays an important role. Here if the negative thickness is passed in this function or any other function which creates a closed shape(rectangle, polygon, etc). Then it creates a filled shape (filled with color). Negative Thickness Filled Circle Positive

Hello Guys, In this tutorial, I will show you how to draw a line in OpenCV. OpenCV comes with lots of built-in functions that make our life easier especially when we are working on image processing .  And there is a function called line  in OpenCV which is used to draw a line. This function takes the following parameters: 1. Image: Takes image object 2. Point 1: Point 1 X and Y  Coordinates 3. Point 2:  Point 2 X and Y  Coordinates 4. Color: Takes color in BGR format 5. Thickness: By default set to 1  (optional) 6. Line Type: By default set to 8-connected .It can also be LINE_AA  or 4-connected  (Optional) 7. Shift: Shifts fractional bits in the point coordinates (Optional) Well it is recommended to use line LINE_AA ( Anti Aliased) as line type. Line Without LINE_AA  (Anti Aliased) You can observe the right and left ends of the line . You will notice curves are showing in a zigzag pattern.  Line With LINE_AA  (Anti Aliased) Now in this image you can observe the curves are smooth

Hi Guyz, In this tutorial, I will discuss the video properties and how to view the video properties of any video file using OpenCV.  A video file contains different types of properties like width, height, frames, etc. Sometimes it is required to take out these basic video details. In order to make this work, easy OpenCV comes with built-in properties to ease out the work for developers. video = cv.VideoCapture("video.mp4")video.get(0) OpenCV has a function named get(propId). Which takes property Identifier as an argument. There are total 22 property identifiers that OpenCV supports.  List of Property Identifiers One can also modify the properties of video file using set function. This function takes two arguments.  1. Index  2. Property Identifier In case, You want to modify the width and height of the video file. video.set(3,320) # Width video.set(4,480) # Height Program #import cv2 moduleimport cv2 as cv#This function shows the properties of a video filedef showProperties

Hello Guys, In this tutorial, I will show you how to play a video file using OpenCV. To play a video file or to stream a webcam OpenCV has a function named  VideoCapture.  This function takes only one argument. If you want to play the video you need to pass the file name with extension. Ex:  nature.mp4. Similarly, If you want to stream your webcam you need to pass a number or device index. Which simply means which webcam you want to access. Just in case, If you have more than one webcam. If you have only one webcam then you have to pass 0 or else if you have two web cameras then for accessing the second web camera you have to pass 1  and so on.  Once we have initialized the video object by calling the VideoCapture function. Then we will use an infinite while loop which will iterate till video.read() method returns true. read() function returns two parameters  1. Boolean – If True video still playing or False if the video is ended.  2. Frame – Here frame is simply your picture.  We h

Hello Guys, In this article, I will discuss about how to write images in OpenCV. For writing images, Opencv has the function named “ imwrite “. This function takes two arguments.  1. Image name with extension  2. Image object This function returns a boolean . If it writes the file successfully then it returns True, otherwise False . # Import cv2 moduleimport cv2 as cv#reading an using imread function without passing any parameter# By default it loads the image in color formatcolored_image= cv.imread("nature.jpg") #imwrite returns True if it writes the file successfully otherwise #returns Falseresult = cv.imwrite("nature.png",colored_image)if result: png_img = cv.imread("nature.png") cv.imshow("Png Image",png_img) cv.waitKey(0) cv.destroyAllWindows()else: print("Error in writing file") Also don’t forget to check my previous OpenCV tutorials.  http://techievaibhav.in/category/programming/opencv/

Hello Guys, In this tutorial, I will discuss how to display an image using OpenCV.  OpenCV comes with the function named imshow  which is used to display images.  imshow function takes two arguments    1. Window name  2. Image object We can show show any number of windows . But the name of each window must be different. # Import cv2 moduleimport cv2 as cv#reading an using imread function without passing any parameter#by default it loads image in color format (BGR format)colored_image= cv.imread("nature.jpg") # loads image in gray formatgray_image= cv.imread("nature.jpg",cv.IMREAD_GRAYSCALE)#Code to display single imagecv.imshow("Colored Image",colored_image)#Passing zero means it will open till you press any key #to close the window. It takes time in milliseconds . So if 500 will be #passed then it will be opened for 500 ms and then it will be closed #automatically.cv.waitKey(0) # This is used to close all opened windowscv.destroyAllWindows() #code to dis

Hi Guyz, In this tutorial, I will discuss how to read an image in OpenCV using python . OpenCV has the function called imread for reading an image. This imread function reads the image in BGR format. BGR stands for Blue Green Red. This function takes two argument. Image path Flag  There are three types of flags which this function takes. IMREAD_COLOR  IMREAD_GRAYSCALE IMREAD_UNCHANGED IMREAD_COLOR : This is the default flag which this function takes automatically. So if you want to read an image in the color format then you don’t have pass any flag. Or you can also pass 0 .  IMREAD_GRAYSCALE : When using this flag it read an image in grayscale format. Or you can also pass  1.   IMREAD_UNCHANGED : Loads an image with transparency (Alpha channel). Or you can also pass -1 . import cv2 as cv """ Reading Colored Image """colored_image= cv.imread("nature.jpg") #Same statement can also be written as colored_image= cv.imread("nature.jpg",cv