Object Detection with YOLOv3 using Emgu.CV in C#

Introduction:

Object detection is a fundamental task in computer vision, and YOLO (You Only Look Once) is a popular real-time object detection algorithm. In this blog, we will explore how to perform object detection using YOLOv3 in C# with the Emgu.CV library. We will build a simple application that can detect objects in real-time using a webcam.

Prerequisites:

To follow along with this tutorial, make sure you have the following prerequisites:

  1. Visual Studio or any C# development environment installed.
  2. Emgu.CV library installed.
  3. Darknet YOLOv3 configuration file (.cfg) and pre-trained weights file (.weights).
  4. COCO dataset class labels file (coco.names).
  5. Webcam or a video source to capture frames.

Step 1: Setting Up the Project First, create a new C# project in your preferred development environment. Make sure you have the Emgu.CV library referenced in your project.

Step 2: Loading YOLOv3 Model and Class Labels In the provided code, we start by loading the YOLOv3 model and the corresponding class labels from the files. Adjust the paths to the configuration file (“yolov3.cfg”), weights file (“yolov3.weights”), and class labels file (“coco.names”) based on your local file system.

Step 3: Setting Backend and Target for DNN Next, we set the preferable backend and target for the DNN (Deep Neural Network) module. In this case, we choose the OpenCV backend and CPU as the target device. However, you can modify these settings based on your hardware capabilities and requirements.

Step 4: Initializing VideoCapture and Frame Processing We create a VideoCapture object to access the webcam or video source. The code inside the while loop continuously captures frames and processes them for object detection.

Step 5: Preprocessing and Forward Pass For each captured frame, we resize it and convert it to the required format for the YOLOv3 model. The frame is then passed through the network for a forward pass, and the output is obtained.

Step 6: Object Detection and Visualization The output from the network is processed to extract the bounding boxes, class indices, and confidence scores for detected objects. We filter out detections with confidence below a certain threshold (0.8 in this case). Non-maximum suppression (NMS) is applied to remove overlapping bounding boxes.

Finally, we draw the bounding boxes and class labels on the frame. The resulting frame is then resized and displayed using the OpenCV imshow function.

Step 7: Exiting the Application The application continues to capture frames and perform object detection until the user presses the ‘Esc’ key. This is achieved by checking for a keyboard event using the CvInvoke.WaitKey function.

Object detection from Webcam

using Emgu.CV;
using Emgu.CV.Dnn;
using Emgu.CV.Structure;
using Emgu.CV.Util;

class Program
{
static void Main(string[] args)
{
// Step 2: Loading YOLOv3 Model and Class Labels
var net = DnnInvoke.ReadNetFromDarknet(“F:\OpenCVTutorials-masters\OpenCVTutorials-master\detection\yolov3.cfg”, “F:\OpenCVTutorials-masters\OpenCVTutorials-master\detection\yolov3.weights”);
var classLabels = File.ReadAllLines(“F:\OpenCVTutorials-masters\OpenCVTutorials-master\detection\coco.names”);

// Step 3: Setting Backend and Target for DNN
net.SetPreferableBackend(Emgu.CV.Dnn.Backend.OpenCV);
net.SetPreferableTarget(Emgu.CV.Dnn.Target.Cpu);

// Step 4: Initializing VideoCapture and Frame Processing
var vc = new VideoCapture(0, VideoCapture.API.DShow);
Mat frame = new();
VectorOfMat output = new();

VectorOfRect boxes = new();
VectorOfFloat scores = new();
VectorOfInt indices = new();

while (true)
{
vc.Read(frame);

CvInvoke.Resize(frame, frame, new System.Drawing.Size(0, 0), .4, .4);

boxes = new();
indices = new();
scores = new();

var image = frame.ToImage<Bgr, byte>();

// Step 5: Preprocessing and Forward Pass
var input = DnnInvoke.BlobFromImage(image, 1 / 255.0, swapRB: true);

net.SetInput(input);

net.Forward(output, net.UnconnectedOutLayersNames);

for (int i = 0; i < output.Size; i++)
{
var mat = output[i];
var data = (float[,])mat.GetData();

for (int j = 0; j < data.GetLength(0); j++)
{
float[] row = Enumerable.Range(0, data.GetLength(1))
.Select(x => data[j, x])
.ToArray();

var rowScore = row.Skip(5).ToArray();
var classId = rowScore.ToList().IndexOf(rowScore.Max());
var confidence = rowScore[classId];

if (confidence > 0.8f)
{
var centerX = (int)(row[0] * frame.Width);
var centerY = (int)(row[1] * frame.Height);
var boxWidth = (int)(row[2] * frame.Width);
var boxHeight = (int)(row[3] * frame.Height);

var x = (int)(centerX – (boxWidth / 2));
var y = (int)(centerY – (boxHeight / 2));

boxes.Push(new System.Drawing.Rectangle[] { new System.Drawing.Rectangle(x, y, boxWidth, boxHeight) });
indices.Push(new int[] { classId });
scores.Push(new float[] { confidence });
}
}
}

// Step 6: Object Detection and Visualization
var bestIndex = DnnInvoke.NMSBoxes(boxes.ToArray(), scores.ToArray(), .8f, .8f);

var frameOut = frame.ToImage<Bgr, byte>();

for (int i = 0; i < bestIndex.Length; i++)
{
int index = bestIndex[i];
var box = boxes[index];
CvInvoke.Rectangle(frameOut, box, new MCvScalar(0, 255, 0), 2);
CvInvoke.PutText(frameOut, classLabels[indices[index]], new System.Drawing.Point(box.X, box.Y – 20),
Emgu.CV.CvEnum.FontFace.HersheyPlain, 1.0, new MCvScalar(0, 0, 255), 2);
}

CvInvoke.Resize(frameOut, frameOut, new System.Drawing.Size(0, 0), 4, 4);
CvInvoke.Imshow(“output”, frameOut);

// Step 7: Exiting the Application
if (CvInvoke.WaitKey(1) == 27)
break;
}
}

}

Conclusion: In this blog post, we learned how to perform real-time object detection using YOLOv3 in C# with the Emgu.CV library. We explored the code that loads the YOLOv3 model, captures frames from a video source, and performs object detection using the model’s output. The detected objects are then visualized by drawing bounding boxes and class labels on the frames.

Introduction to web3 in c# using .Net and Nethereum.

Web3 is a term that refers to the next generation of the World Wide Web, where decentralized technologies are used to build applications that are more open, transparent, and secure. Web3 incorporates blockchain technology and smart contracts to enable peer-to-peer transactions, decentralized identity, and decentralized applications (dApps). In the context of C# and .NET development, Nethereum is a powerful library that allows you to interact with the Ethereum blockchain using C#.

Started with QuickNode

QuickNode is a platform that provides infrastructure and hosting services for blockchain and Web3 applications. It allows developers to easily deploy and manage their own nodes, which are essential for interacting with various blockchain networks. QuickNode supports a wide range of blockchain networks, including Ethereum, Bitcoin, Binance Smart Chain, and more.

By using QuickNode, developers can access the full functionality of blockchain networks without the need to set up and maintain their own infrastructure. QuickNode offers reliable and scalable node hosting, real-time monitoring, API access, and developer tools to simplify the process of building decentralized applications (dApps) and interacting with blockchain networks.

Step1: Go to https://QuickNode.com/, create account and verify your email.

Step2: Select your Plan

Step3: Create your endpoint

, the URL in the HTTP provider “https://black-indulgent-mountain.discover.quiknode.pro/d0129a8c1559a7d8f6c69a6641591f0a7813e561/” is passed as a parameter when creating a new instance of the Web3 class. This URL specifies the endpoint of the QuikNode service that hosts the Ethereum node.

How to connect to Ethereum using .NET (Nethereum)

Nethereum is a .NET integration library for Ethereum, which allows developers to interact with the Ethereum blockchain using .NET and C#. It provides a comprehensive set of tools and functionalities for building decentralized applications (dApps) and interacting with Ethereum smart contracts.

Installing Nethereum

Nethereum requires .NET Core or .NET Framework(4.5.1+) installed. We’ll install .NET Core SDK to make Nethereum work. Download and install the .NET Core SDK ver 3.1 based on your operating system. Then go to your terminal/command line and type the following.

$ dotnet new console -o nethereuma

This will create a new .NET application in the current directory. You can give your application any name

Now cd into your application.

$ cd nethereuma

Add package reference to Nethereum.Web3

$ dotnet add package Nethereum.Web3

This might take a while. After the package reference is added, download/update the package by typing the following.

$ dotnet restore

If everything goes right, Nethereum will be added to your system with nethereum web3 package.

Booting our Ethereum node

After you’ve created your free ethereum endpoint, copy your HTTP Provider endpoint:

You’ll need this later, so copy it and save it.

Connecting with Ethereum

Now go to your .NET app folder and open the Program.cs C# file in a text editor .

Connect with Ethereum and then get the latest block number from the Ethereum blockchain.

class Program
{
    static void Main()
    {
        GetBlockNumber().Wait();
       
    }

static async Task GetBlockNumber()
{
     var web3 = new Web3("ADD_YOUR_ETHEREUM_NODE_URL");
     var latestBlockNumber = await     web3.Eth.Blocks.GetBlockNumber.SendRequestAsync();
     Console.WriteLine($"Latest Block Number is: {latestBlockNumber}");
        }
}

Generate a Ethereum Address

While signing in to any platform on the internet, you need to authenticate using a combination of credentials. Consider an Ethereum address as your username and a corresponding private key as the password. While your Ethereum address is public and can be shared, the private key must always be kept secret. Using this combination lets you interact with the Ethereum blockchain. An Ethereum address is your identity on the blockchain, and it looks like this “0x6E0d01A76C3Cf4288372a29124A26D4353EE51BE”.

 static void GenerateEthereumAddress()
    {
        // Generate a new Ethereum account
        var ecKey = Nethereum.Signer.EthECKey.GenerateKey();
        var privateKey = ecKey.GetPrivateKey();
        var address = ecKey.GetPublicAddress();

        // Output the generated address and private key
        Console.WriteLine("Ethereum Address: " + address);
        Console.WriteLine("Private Key: " + privateKey);
    }

Run the code

Web 3.0

Web 3.0, also known as the third-generation internet, is the next evolution of the World Wide Web. It provides a data-driven Semantic Web employing a machine-based understanding of data with the objective of developing a more intelligent and connected web experience for users.

The Web of today is static and unable to adjust to the individual needs of each person experiencing it. Web 3.0 promises to be more dynamic and interactive. By implementing artificial intelligence and blockchain technology, it will redefine the web experience with structural changes to ensure democratization across all aspects of the internet.

In Web 3.0, data is stored securely and distributed across many devices, removing the need for centralized servers. Such a design also reduces the risks of massive data leaks because data is no longer centrally stored — making it more resilient to compromise.

Evolution of Web – 1.0, 2.0, and 3.0

Web 1.0: Static, Read-Only

This first version of the internet is acknowledged as the first stage of the world wide web evolution. It is characterized as a read-only web experience. Users can read information on web pages driven by web browsers, HTML, HTTP and URL technology. The experience is highly decentralized, and there are no search engines. Instead, Web 1.0 content is static and hyperlinked together. Web 1.0 is also referred to as the Syntactic Web, and the user’s role is limited.

Web 2.0: Read-Write

As the second generation of the world wide web, Web 2.0 is known as the read-write Web or the social Web because it facilitates interaction between users and sites. Driven by mobile, social networks and cloud technology, Web 2.0 users can read and write content on websites and applications and distribute it between sites.

A small group of big tech companies like Meta (previously Facebook), YouTube and Twitter own most of the user data associated with Web 2.0. The data is highly centralized with these tech giants. This centralization of data (and power) and monetization of users is spurring the need for Web 3.0.

Web 3.0 Read-Write-Interact-Web

Web 3.0 is highly decentralized, driven by machine learning and artificial intelligence, and leverages blockchain technology. The result is real-world human communication. Users retain control over their data and content, and they can sell or trade their data without losing ownership, risking privacy or relying on intermediaries. In this business model, users can log into a website without having their internet identity tracked.

The term Web 3.0, coined by reporter John Markoff of The New York Times in 2006, refers to a new evolution of the Web which includes specific innovations and practices.

Features of Web3.0

  1. Semantic Web: The next evolution of the Web involves the Semantic Web. The Semantic Web improves the abilities of web technologies to generate, share and connect content through search and analysis by understanding the meaning of words rather than by keywords or numbers.
  2. Artificial Intelligence: By combining semantic capabilities with natural language processing, computers can understand information on a human-like level to provide faster and more relevant results
  3. 3D Graphics: Three-dimensional design is used extensively in websites and services in Web 3.0. Museum guides, computer games, eCommerce, geospatial contexts and more are all common examples of this.
  4. Connectivity: With Web 3.0, information is more connected thanks to semantic metadata. As a result, the user experience evolves into a new level of connectivity that leverages all available information.
  5. Ubiquity: Internet content and services can be accessed anywhere at any time via any number of devices, rather than exclusively via computers and smartphones. Web 2.0 is already ubiquitous in many ways, but the growth of IoT devices will take it to new levels.
  6. Blockchain: With blockchain technology, user data is protected and encrypted. This prevents large companies from controlling and/or using users’ personal data for their gain.
  7. Decentralized: Decentralized data networks store data within a peer-to-peer interconnection. Users maintain ownership over their data and digital assets and are able to log in securely over the internet without being tracked.
 Examples of Web3 applications
  1. Ethereum. Perhaps the best-known Web3 protocol, this decentralized platform supports a native cryptocurrency plus a vast ecosystem of decentralized apps. The Ethereum platform hosts most of the Web3 apps that exist today.
  2. Brave. Brave is a Web3-based browser that enables users to directly monetize their content consumption and creation. Users are rewarded for viewing ads and can be compensated directly for producing original content.
  3. Uniswap. This Ethereum-based protocol supports a decentralized exchange that aims to be a Web3 version of today’s stock and commodity exchanges. Governance of the Uniswap protocol is also decentralized, with full control distributed among UNI tokenholders.
  4. Aave. This Web3 lending and borrowing platform enables users to earn interest on deposits, plus borrow assets without requiring approval from centralized intermediaries.
  5. RealT. Real estate investors may be interested in RealT, a Web3 app that aims to tokenize real estate. RealT allows investors to earn rental income from fractional ownership shares in properties.
  6. Set protocol. Internet users can access the Set protocol to automate investing and rebalancing of crypto assets. The protocol uses Web3 tech to enable investors to predefine their investing rules and strategies. Perhaps, one day, the protocol could move from crypto assets to traditional asset classes.
  7. Nexus Mutual. Web3 technology can support decentralized insurance platforms, and Nexus Mutual is exactly that. The platform is focused on insuring crypto holdings and covering smart contract failures.
  8. InstaDApp. This Web3 banking portal aims to simplify access to multiple decentralized finance (DeFi) protocols. The dApp features portfolio management and debt refinancing tools.

Work-life Balance: It’s no longer good to have but a Necessity

Nowadays, mental health has become the topmost priority for all employees in the workspace. As a professional, in today’s fast-paced world it’s becoming increasingly difficult to achieve a work-life balance. Achieving a healthy work-life balance is critical for your long term success and well-being. Maintaining a healthy work-life balance is not just a matter of personal wellbeing, but also a critical component of creativity and productivity.

At its core, work-life balance refers to effectively managing your time and energy between work responsibilities and personal life. This includes everything from spending quality time with family and friends, pursuing hobbies and interests, maintaining a healthy lifestyle, and excelling in your professional career.

To achieve work-life balance is essential for overall well-being. It helps reduce stress and burnout while enhancing your personal and professional growth. When individuals can balance their personal and professional lives, they tend to be more productive, efficient, and creative in their work, ultimately leading to better outcomes.

In contrast, when work-life balance is out of sync, individuals may experience a range of negative consequences, such as poor physical and mental health, decreased job satisfaction, and strained relationships with loved ones. Individuals need to prioritize their personal well-being and maintain a healthy work-life balance to achieve long-term success and happiness.

Importance of Work-Life Balance:

Achieving a healthy work-life balance is crucial for maintaining overall well-being and happiness. It is also a critical contributor for improving employee productivity and the performance of an organization. Without a healthy work-life balance, an organization will end up with a burned-out workforce with low motivation, lack of focus and poor performance. 

Organizations that can achieve a positive work-life balance for their employees also build a better employer reputation in the process, which helps attract and retain good talent. At the same time, the workforce with a positive work-life balance has fewer health problems, is highly engaged and more mindful of their work commitments. 

Ways to achieve a Balanced Life:

  • Prioritizing your life and settings goals: To achieve work-life balance, prioritize your life and set goals that align with your values. Set SMART goals (specific, measurable, achievable, relevant, and time-bound) that will help you stay focused and motivated. Identify your priorities and set realistic goals for each day or week. Use tools like calendars or planners to keep track of deadlines and appointments.
  • Setting Realistic Expectations for Yourself and Others: Setting Realistic Setting unrealistic expectations for yourself or others can lead to burnout and stress. Be honest about what you can accomplish in a day or week, both at work and in your personal life. Communicate these expectations clearly with others so they understand what they can expect from you.
  • Delegating Tasks and Asking for Help When Needed: Don’t be afraid to delegate tasks or ask for help when needed to save you time and allow others to contribute their skills and expertise. This is one of the best work-life balance benefits, so don’t miss it.
  • Learn to say no: It’s okay to say no when you feel like you have too much on your plate. It’s important to recognize when you are feeling overwhelmed and to communicate your needs effectively. This can include saying “no” to additional tasks or responsibilities prioritizing your workload and delegating tasks to others can also help you manage your workload effectively and avoid burnout. Learning to set boundaries and manage your workload in a healthy way is essential for achieving balance in your life, both at work and at home.
  • Learn to manage stress: Stress is an inevitable part of life, especially in a corporate environment. Mindfulness can help you stay focused and present in the moment. This can include meditation, deep breathing, exercise etc
  • Creating a Supportive Work Environment: Creating a supportive work environment is crucial for achieving work-life balance. This means openly communicating with supervisors about workload and expectations. By integrating work and personal life, we can achieve a healthy balance that allows you to professionally and personally thrive.

Conclusion:

Achieving work-life balance may seem like an elusive goal, but it is definitely worth striving for. You can improve your work-life balance and enjoy a happier, healthier life by taking small steps and implementing our discussed tips.

Start with small changes and build from there. Prioritize your time, set boundaries, and practice self-care. Small steps can lead to big results. Don’t forget to celebrate your achievements along the way! Acknowledge your progress towards achieving work-life balance and reward yourself for your hard work. This will help keep you motivated to continue striving for balance.

Prioritizing work-life balance has numerous benefits for both your physical and mental health. It can reduce stress, improve relationships, increase productivity, and lead to greater overall happiness.  Remember that to achieve work-life balance is an ongoing process that requires effort and dedication. Don’t give up if you experience setbacks or challenges along the way. Keep striving towards a balanced life – it’s worth it!

In conclusion, prioritizing work-life balance is essential for our well-being in today’s fast-paced world. By implementing these tips and taking small steps towards achieving balance, we can enjoy happier, healthier lives with more time for the things that matter most to us.

Blockchain

Blockchain technology design vector illustration

If we want to understand the Blockchain we can say that in simple terms, a blockchain is a digital ledger of transactions that is decentralized, meaning that it is not controlled by a central authority, like a bank or government. Instead, it is maintained by a network of computers that all work together to verify and record transactions.

To understand how a blockchain works, imagine a group of people who are all keeping track of their transactions on a piece of paper. Each time someone makes a transaction, they write it down on their paper, along with the time, amount, and other details. This creates a record of all the transactions that have taken place.

Now imagine that instead of just one piece of paper, there are thousands of them, each being kept by a different person. Each time a transaction is made, it is recorded on all of the pieces of paper, and each person checks to make sure that the transaction is valid. If everything checks out, the transaction is added to the ledger, and everyone has a copy of the updated ledger.

This is essentially how a blockchain works, except instead of paper, it uses digital blocks of information that are linked together in a chain. Each block contains a record of several transactions, and when a new block is added to the chain, it is verified by the network of computers to make sure that it is valid. Once it has been verified, it is added to the chain and cannot be changed or deleted.

One of the key features of blockchain technology is its security. Because the ledger is decentralized and maintained by a network of computers, it is extremely difficult for anyone to hack or alter the information. This makes it a great way to store sensitive information, like financial transactions or personal data.

Another advantage of blockchain is its transparency. Because every transaction is recorded and verified by the network, it is possible to trace the history of a particular asset or transaction all the way back to its origin. This can be particularly useful in industries like supply chain management, where it is important to track the movement of goods from one place to another. Blockchain is a digital ledger of transactions that is decentralized and maintained by a network of computers. It is secure, transparent, and can be used for a wide range of applications. While it may seem complex at first, the basic idea is relatively simple, and it has the potential to revolutionize the way we store and share information.

So above we tried to understand what is blockchain and how its used in a layman’s way. Now we will understand it from the prespective of technical view.

a blockchain is a decentralized ledger of transactions that are secured through cryptographic protocols. In other words, it’s a digital database that is distributed across a network of computers, with each computer storing a copy of the database.

The key feature of a blockchain is its decentralized nature. Traditional databases are centralized, meaning that they are owned and operated by a single entity, such as a bank or government. This makes them vulnerable to hacking, censorship, and corruption. In contrast, a blockchain is decentralized, which means that no single entity has control over the data. Instead, it is controlled by the network of computers that participate in the system.

One of the most popular implementations of blockchain technology is Bitcoin. Bitcoin is a decentralized digital currency that operates on a blockchain. It was created in 2009 by an unknown person using the pseudonym Satoshi Nakamoto. Since then, it has grown in popularity, with a market capitalization of over $1 trillion at the time of writing.

The Bitcoin blockchain is a distributed ledger that records every Bitcoin transaction. Each transaction is verified by a network of computers, known as nodes, that are connected to the blockchain. Nodes work together to validate transactions by solving complex mathematical equations, a process known as mining. When a block of transactions is validated, it is added to the blockchain, creating a permanent and unalterable record.

The security of a blockchain is ensured by a combination of cryptographic protocols, including hash functions and digital signatures. Hash functions are algorithms that take an input and generate a fixed-size output, known as a hash. Each block in the blockchain contains a hash of the previous block, creating a chain of blocks that are linked together. This creates an immutable record that cannot be tampered with.

Digital signatures are used to ensure that transactions are authentic. Each user on the network has a public key and a private key. The public key is used to verify the digital signature, while the private key is used to create the signature. When a user makes a transaction, they use their private key to create a digital signature that is attached to the transaction. This ensures that the transaction is authentic and cannot be forged.

Another key feature of a blockchain is its transparency. Because the ledger is distributed across a network of computers, anyone can view the transactions on the blockchain. This makes it ideal for use cases where transparency is important, such as supply chain management or voting systems.

Blockchain technology has the potential to revolutionize many industries, including finance, healthcare, and logistics. Its decentralized and secure nature makes it ideal for storing sensitive information, such as medical records or financial transactions. However, it’s important to note that blockchain technology is still in its early stages and there are many challenges that need to be overcome, such as scalability and energy consumption.

Let’s make a simple Blockchain program in Steps.
Step 1: Create the Block class
The first step is to create a Block class that will store the data for each block in the blockchain. Here’s an example:

public class Block
{
    public int Index { get; set; }
    public DateTime Timestamp { get; set; }
    public string Data { get; set; }
    public string PreviousHash { get; set; }
    public string Hash { get; set; }
}

Each block will have an index, a timestamp, some data, a hash of the previous block in the chain, and a hash of the current block.

Step 2: Create the Blockchain class
Next, we’ll create a Blockchain class that will manage the chain of blocks. Here’s an example:

public class Blockchain
{
    private List<Block> _chain;

    public Blockchain()
    {
        _chain = new List<Block>();
        AddGenesisBlock();
    }

    private void AddGenesisBlock()
    {
        _chain.Add(new Block
        {
            Index = 0,
            Timestamp = DateTime.Now,
            Data = "Genesis Block",
            PreviousHash = null,
            Hash = CalculateHash(0, DateTime.Now, "Genesis Block", null)
        });
    }

    private string CalculateHash(int index, DateTime timestamp, string data, string previousHash)
    {
        using (SHA256 sha256 = SHA256.Create())
        {
            string input = index + timestamp.ToString("yyyy-MM-dd HH:mm:ss.fff") + data + previousHash;
            byte[] bytes = sha256.ComputeHash(Encoding.UTF8.GetBytes(input));
            StringBuilder builder = new StringBuilder();
            for (int i = 0; i < bytes.Length; i++)
            {
                builder.Append(bytes[i].ToString("x2"));
            }
            return builder.ToString();
        }
    }
}

The Blockchain class contains a list of blocks, with the first block being the genesis block. We also have a private method, CalculateHash, that takes in the index, timestamp, data, and previous hash and returns the SHA256 hash of that input.

Step 3: Add blocks to the chain
Now that we have our classes set up, we can add some blocks to the chain. Here’s an example:

Blockchain blockchain = new Blockchain();
blockchain.AddBlock("Transaction 1");
blockchain.AddBlock("Transaction 2");

The AddBlock method takes in some data, creates a new block with that data, and adds it to the chain.

Step 4: Verify the blockchain
Finally, we can verify that our blockchain is valid by checking that each block’s hash matches the previous block’s hash. Here’s an example:

bool isValid = true;
for (int i = 1; i < blockchain.Count; i++)
{
    Block currentBlock = blockchain[i];
    Block previousBlock = blockchain[i - 1];
    if (currentBlock.PreviousHash != previousBlock.Hash)
    {
        isValid = false;
        break;
    }
}
Console.WriteLine($"Is blockchain valid? {isValid}");

This code loops through each block in the chain and checks that its PreviousHash matches the previous block’s Hash. If any of the blocks are invalid, the isValid flag is set to false.

And that’s it! With these simple steps, we’ve created a functioning blockchain in C#.

In conclusion, a blockchain is a decentralized ledger of transactions that is secured through cryptographic protocols. It uses a network of computers to validate transactions and ensure the security of the ledger. Its transparency and security make it ideal for a wide range of applications, but there are still many challenges that need to be addressed before it can reach its full potential.

Dependency injection (DI)

Introduction

As software systems grow in complexity, managing dependencies becomes increasingly challenging. One solution to this problem is Dependency Injection (DI). DI is a technique that helps to decouple components in a system by removing the responsibility of creating and managing dependencies from the components themselves.

In this article, we’ll take a closer look at DI in C#. We’ll define what DI is, its features, and why it’s beneficial. Finally, we’ll provide an example of how to implement DI in a C# application.

What is Dependency Injection?

Dependency Injection (DI) is a design pattern in object-oriented programming that aims to make the code more modular and maintainable by reducing the coupling between components. In C#, DI is achieved by using a third-party DI container library or by manually injecting dependencies into classes.

Dependency Injection involves three main components:

  1. Dependency: A dependency is an object that is needed by another object to perform its tasks.
  2. Injection: Injection is the process of passing a dependency to an object.
  3. Container: A container is responsible for managing the dependencies and their lifecycles.

By using DI, the application becomes more modular, testable, and maintainable.

Features of Dependency Injection

There are several features of DI that make it useful in software development:

Decouples components

DI decouples components in a system by removing the responsibility of creating and managing dependencies from the components themselves. This enables components to be more modular and flexible, allowing for easier testing and maintenance.

Increases code reuse

DI increases code reuse by promoting the use of smaller, more focused classes with clear responsibilities. This enables the reuse of code across multiple components in the application.

Facilitates testing

DI facilitates testing by allowing dependencies to be mocked or replaced with test implementations. This makes it easier to test individual components in isolation without relying on the behavior of other components.

Enables configuration flexibility

DI enables configuration flexibility by allowing dependencies to be swapped out at runtime. This makes it easier to change the behavior of the application without modifying its source code.

Let’s take a look at an example of how to use DI in a C# application. Suppose we have a UserService class that needs to send emails to users. Instead of creating an EmailService instance inside the UserService, we can use DI to inject the EmailService as a dependency into the UserService.

First, we’ll define an interface for the EmailService:

public interface IEmailService
{
    void SendEmail(string to, string subject, string body);
}

Next, we’ll define the EmailService class that implements this interface:

public class EmailService : IEmailService
{
    public void SendEmail(string to, string subject, string body)
    {
        // Implementation to send email
    }
}

Now, we’ll modify the UserService to accept an IEmailService instance as a constructor parameter:

public class UserService
{
    private readonly IEmailService _emailService;

    public UserService(IEmailService emailService)
    {
        _emailService = emailService;
    }

   

Conclusion:

In conclusion, Dependency Injection (DI) is a technique used in software development to manage dependencies between objects and components. DI enables decoupling of components, increased code reuse, easier testing, and configuration flexibility. By separating the creation of an object from its use, DI makes code more modular, flexible, and easier to test and maintain.

Creating Multiple- Layouts For Different Razor Pages In Blazor

Introduction

Blazor by default comes with layouts that are shared across various components, but there are times when building an application you need to have multiple layouts for various pages, this article will show how we can make multiple layouts in blazor.

Step 1-Choose a Blazor Server App

Choose .Net 6.0

Project Name

By Default Main Layout

Create Support Layout

Optional base class for components that represent a layout. Alternatively, components may implement IComponent directly and declare their own parameter named Body.

By Default Nav Menu

Create a Support Layout

Create a One More Layout LoginLayout

Change By Default / Url to /home

Change By Default App Url to Login and also use @layout layoutName

Create a One More Page Register.razor for registration

By Default change index.razor to Login.razor

when i can click on Admin Admin Dashboard Open It has different Layout

When i can click on Support Team A New DashBoard Open It has also a different Layout

OpenCV in .Net

What Is Computer Vision?

Computer vision mainly originated from the image processing field, and image processing comes from signal processing.

It deals with creating and duplicating human vision using computer software and also hardware. OpenCV mainly concentrates on image processing, video capture, and analysis. It also includes features like object detection and face detection.

Computer Vision Also Overlaps With the Following Fields:
Image Processing – It focuses on image manipulation.
Pattern Recognition − It classifies patterns with the help of various techniques.
Photogrammetry − Image measurements are calculated and procured with great accuracy using Photogrammetry.

Applications of Computer Vision

It is used for object tracking, which can locate items in a picture and then follow them around the frame.
It is used for image reconstruction, where numerous frames are passed in at the same time and the image attributes are reconstructed using the samples provided.
It is used for video processing, which is comparable to object tracking in that it analyses video frames for objects and then tracks them in the frame.

What is OpenCV?

An open-source package called OpenCV (Open Source Computer Vision) has more than 2500 optimised algorithms in it.
It may be used with many different programming languages, including C++, Python, and Java, to create computer vision applications. Many tools, including image filtering, feature detection, object recognition, and tracking, are available in OpenCV for processing images and videos.

How to implement OpenCV in .NET?

In order to use OpenCV with.NET, a C++-to-.NET bridge must be built because OpenCV is a C++ library. It is possible to accomplish this by utilising a wrapper library, such as Emgu CV, a free and open-source C# wrapper for OpenCV.Emgu CV provides a C# interface for OpenCV, making it easier to use OpenCV with .NET.

To implement OpenCV in .NET using Emgu CV, follow these steps:

Step 1: Download and install Emgu CV

Download the latest version of Emgu CV from the official website and install it on your system.
Emgu CV comes with pre-built binaries for Windows, Linux, and Mac, so make sure to download the correct version for your system.

Step 2: Create a new project

Create a new .NET project in Visual Studio, and add a reference to the Emgu.CV.World.dll file. This file contains the C# wrapper for OpenCV.

Step 3: Use Emgu CV in your project

To use Emgu CV in your project, you first need to create an instance of the CvInvoke class, which is used to invoke OpenCV functions.

OpenCV uses in C#

The following are the top applications for OpenCV C#:

Detecting Objects:
We are able to identify any object using object detection, including faces, human bodies, and animals. A pattern of geometric method is used.

Object Identification:
Object recognition and object detection are related concepts. In order to recognise things, we do not need to first detect them; instead, we must compare the results to those previously saved in the database.

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Tracking of Objects:
Tracking of Objects is based on video analysis. It means that we can get the recordings or recorded videos from the webcam. And then, by performing image processing techniques on the photo itself, we can learn in detail about the photo and objects in the image.

Image Reconstruction:
Using Image Reconstruction, we can get the reconstruction of the image properties. This can be done by using the samples provided by passing them into multiple frames.

Video Processing:
Video Processing can be comparable to object tracking. It is because of this process that we also need to analyze by seeing the video frames in order to detect the objects in the image. This is followed by tracking them in the video frames. The speed of the object’s movement can also be tracked using this.

Examples:

This is a simple C# program that uses EmguCV library to apply a Gaussian blur effect on an image. The program reads an image file “image.png” from the specified path, applies a Gaussian blur filter with a kernel size of 7×7, and displays the original and blurred images using the Imshow() method. The WaitKey(0) method is used to wait for the user to press a key before the program exits.

Another example:

The program starts by loading an image using the Image<Bgr, byte> class. The image is loaded from the file path specified in the constructor.

Next, the program converts the image to grayscale using the Convert<Gray, byte> method. This is necessary because the face detection classifier requires a grayscale image as input.

The program then loads the face detection classifier using the CascadeClassifier class. The XML file containing the Haar cascade for face detection is specified in the constructor.

The program then detects the faces in the image using the DetectMultiScale method of the CascadeClassifier object. The method takes in the grayscale image, a scale factor, a minimum number of neighbors, and a minimum size for the detected objects. These parameters can be adjusted to fine-tune the face detection performance.

Finally, the program draws a rectangle around each detected face using the Draw method of the Image<Bgr, byte> class. The rectangle is drawn in red with a thickness of 2 pixels.

The result is displayed using the CvInvoke.Imshow method, which opens a new window and displays the image. The CvInvoke.WaitKey method is used to wait for the user to press a key before closing the window.

Blazor LifeCycle

Blazor WebAssembly: An Overview | Syncfusion Blogs

In simple terms we can say that Blazor is a tool that helps people make websites. When we make websites with Blazor, we use something called “components” which are like building blocks that we put together to make the website.

Each component goes through different stages of its life, like when it’s created, when it’s shown on the website, when it’s updated, and when it’s removed from the website. These stages are called the component’s “lifecycle”.

When a component is first created, it goes through a stage called “initialization” where it sets up its starting point. After that, it goes through a stage called “rendering” where it creates the code that makes up the component on the website. If something about the component changes, like the information it’s showing, it goes through a stage called “update” where it makes those changes to the code. And when the component is removed from the website, it goes through a stage called “destruction” where it cleans up after itself.

During each of these stages, there are different things we can do to customize the behavior of the component. For example, we can use a special method called “SetParametersAsync” to update the component’s properties and trigger a re-render of the component when something changes.

Understanding how the component lifecycle works is important because it helps us make websites that are fast and respond quickly when people use them. By using the different lifecycle methods, we can make our components work more efficiently and help our website run smoothly.

ASP.NET Core Razor component lifecycle | Microsoft Learn

Now, lets understand it from the developing prespective.

The Blazor component model is built around the concept of a component’s lifecycle, which is a series of events that occur from the time a component is created until it is removed from the page.

Here’s an overview of the Blazor component lifecycle:

Initialization: When a component is first created, it goes through an initialization phase where it sets up its initial state and any dependencies it needs.

Rendering: After initialization, the component enters a rendering phase where it generates the initial HTML for the component and any child components.

Update: When a component’s state or properties change, it goes through an update phase where it re-renders itself with the new data.

Destruction: When a component is removed from the page, it goes through a destruction phase where it cleans up any resources it was using.

Throughout these phases, Blazor provides various lifecycle methods that we can use to customize the behavior of their components. These methods include OnInitialized, OnAfterRender, OnParametersSet, and Dispose.

Understanding the Blazor component lifecycle is important for us because it allows us to build efficient and performant web applications that respond quickly to user interactions and data changes. By leveraging the various lifecycle methods, we can optimize the components for different scenarios, such as improving initial load times or reducing unnecessary re-renders.

Initialization is the first phase in the lifecycle of a Blazor component. During this phase, the component is created and its initial state is set up. The following steps occur during initialization:

Construction: When a component is first created, its constructor is called. This is where the component’s dependencies are typically injected and any other setup work is done.

Dependency Injection: Once the component is constructed, its dependencies are injected by the Blazor runtime. Dependencies can include services, other components, or anything else the component needs to function.

Parameter Initialization: After the component’s dependencies are injected, its parameters are initialized. Parameters are values that are passed to the component from its parent component, and they can be used to set up the initial state of the component.

OnInitialized: Finally, the OnInitialized lifecycle method is called. This method is a hook that developers can use to perform additional setup work, such as setting up event handlers or initializing any internal state that is not dependent on the component’s parameters.

During the component initialization stage, the component is created and its properties and state are initialized. This stage is typically used to perform any setup logic, such as initializing variables or subscribing to events.

The rendering stage is where the component’s user interface is constructed and updated. When the component is first rendered, its Render() method is called, which generates the HTML for the component. This method is called again whenever the component’s state or properties change, which triggers a re-render of the component. Blazor uses a virtual DOM, similar to other modern web frameworks, to optimize the rendering process and minimize the number of DOM manipulations needed.

In terms of rendering methods, Blazor provides two main approaches: server-side rendering and client-side rendering. Server-side rendering (SSR) involves rendering the component on the server and sending the HTML to the client, while client-side rendering (CSR) involves rendering the component on the client’s browser using JavaScript.

The SetParametersAsync method is one of the lifecycle methods that is called when a component is initialized or when any of its parameters change. This method is responsible for updating the component’s properties and triggering a re-render of the component. The SetParametersAsync method is defined in the IComponent interface, which is implemented by all Blazor components.

The method takes a ParameterView object as its parameter, which represents a collection of parameters that are passed to the component. The SetParametersAsync method is called whenever the component is first initialized or whenever any of its parameters change. When the method is called, the component checks if any of its properties have changed and updates them accordingly. If any of the properties have changed, the component triggers a re-render of its UI.

In summary, the SetParametersAsync method is an important lifecycle method in Blazor that is called when a component is initialized or when any of its parameters change. This method is responsible for updating the component’s properties and triggering a re-render of the component.

Here’s an example of a Blazor component that uses some of these lifecycle methods:

@code {
[Parameter]
public string Title { get; set; }
private Timer _timer;

protected override void OnInitialized()
{
    // Initialize the timer
    _timer = new Timer(1000);
    _timer.Elapsed += (sender, args) => InvokeAsync(StateHasChanged);
    _timer.Start();
}

protected override void OnParametersSet()
{
    // Update the timer interval based on the title
    _timer.Interval = Title.Length * 100;
}

protected override async Task OnAfterRenderAsync(bool firstRender)
{
    if (firstRender)
    {
        // Wait for the DOM to update
        await Task.Delay(100);

        // Focus the title element
        var element = await JSRuntime.InvokeAsync<ElementRef>("getElementById", "title");
        await element.FocusAsync();
    }
}

public void Dispose()
{
    // Dispose the timer
    _timer.Dispose();
}
}

In addition to the SetParametersAsync method, there are other lifecycle methods that can be used to customize the behavior of a Blazor component:

OnInitialized: This method is called after the component has been constructed and its dependencies have been injected. This is a good place to perform any additional setup work that is not dependent on the component’s parameters.

OnParametersSet: This method is called after the component’s parameters have been set or updated. This is a good place to perform any additional setup work that is dependent on the component’s parameters.

OnAfterRender: This method is called after the component has been rendered to the DOM. This is a good place to perform any additional setup work that requires access to the DOM, such as initializing third-party libraries.

Dispose: This method is called when the component is removed from the page. This is a good place to clean up any resources that the component was using, such as event listeners or timers.

Here’s an example of a Blazor component that uses some of these lifecycle methods:

@code {
[Parameter]
public string Title { get; set; }
private Timer _timer;

protected override void OnInitialized()
{
    // Initialize the timer
    _timer = new Timer(1000);
    _timer.Elapsed += (sender, args) => InvokeAsync(StateHasChanged);
    _timer.Start();
}

protected override void OnParametersSet()
{
    // Update the timer interval based on the title
    _timer.Interval = Title.Length * 100;
}

protected override async Task OnAfterRenderAsync(bool firstRender)
{
    if (firstRender)
    {
        // Wait for the DOM to update
        await Task.Delay(100);

        // Focus the title element
        var element = await JSRuntime.InvokeAsync<ElementRef>("getElementById", "title");
        await element.FocusAsync();
    }
}

public void Dispose()
{
    // Dispose the timer
    _timer.Dispose();
}
}


In this example, the component uses the OnInitialized method to set up a timer that updates the component’s state every second. The OnParametersSet method is used to update the timer interval based on the length of the Title parameter. The OnAfterRenderAsync method is used to focus the Title element after the component has been rendered to the DOM. Finally, the Dispose method is used to dispose of the timer when the component is removed from the page.

Overall, understanding the Blazor component lifecycle and its various methods is important for building efficient and performant web applications.

BLAZOR ,REACT JS & ANGULAR JS

Are you tired of using JavaScript for building web applications? Have you ever wished that there was a better way to build web applications without having to deal with the complexities of JavaScript? Well, there is! Blazor is a new web development framework that allows developers to build interactive web applications using C# instead of JavaScript.

In this blog post, we will explore some of the reasons why Blazor is better than JavaScript for web development. We’ll discuss the advantages of using Blazor, including its simplified development process, increased performance, and code reusability etc.

What Does Blazor Offer?

Compatibility with various operating systems – The code which is written in Visual Studio improves overall Blazor app development and offers mixtures of operating systems like macOS, Linus, and Windows. 

Exchanging .NET code and libraries -The Blazor based apps use the existing .NET libraries. All credit goes to the standardized format of .NET for building an official explicit .NET libraries and .NET code.

  • Blazor shares the server-side code and client-side code: Blazor allows developers to reuse code between the front end and back end.
  • Dependency injection: Dependency injection is a usable object that can act as a service in Blazor. Blazor uses dependency injection in its applications to achieve inversion of control. It allows providing objects with dependencies. In Blazor, dependency injection can be divided into classes: injector, client, and service. Blazor also features different injectors such as constructors, properties, and methods.
  • Visual Studio Code: We can develop Blazor apps using visual studio code since both are Microsoft products. When you develop an app in the Blazor framework, VS Code will help you utilize its features easily.
  • Interoperability with JavaScript: Blazor uses interop functionality in Blazor WebAssembly to handle DOM manipulations. Also, this JavaScript functionality can use browser API calls in Blazor WebAssembly. Therefore, Blazor apps can use .NET methods with JavaScript functions.
  • Unrestricted access and open source: Blazor is connected to the open-source.NET platform, which has a strong and reliable network of almost 60,000 supporters from over 3,700 distinct companies. 

While both Blazor and JavaScript can be used to build web applications, they have different strengths and use cases. Blazor is particularly useful for developers who are already familiar with C# and want to build web applications without having to learn JavaScript. JavaScript, on the other hand, is more widely used and has a larger community of developers and resources available. Ultimately, the choice between Blazor and JavaScript will depend on the specific requirements of your project and the skillset of your development team.

Blazor Vs React JS

Blazor and React are two different web development frameworks that can be used to build modern web applications.Blazor is a web framework developed by Microsoft that allows developers to build interactive web applications using C# instead of JavaScript, while React is a JavaScript library for building user interfaces.

One of the main differences between Blazor and React is the language used to build applications. Blazor uses C#, while React uses JavaScript. This means that developers who are already familiar with C# may find it easier to work with Blazor, while those who are more experienced with JavaScript may prefer to use React.

Another difference between Blazor and React is the way they handle user interface rendering. Blazor uses a server-side rendering model, where the HTML for the user interface is generated on the server and sent to the client, while React uses a client-side rendering model, where the HTML is generated on the client-side using JavaScript.

ReactBlazor
TypeFront-End Library – focuses on the client UI and interactions of your website.Full Framework – client side (WASM) and server side (ASP.NET)
DeveloperFacebookMicrosoft
LicenseMITApache
LanguageJavaScript/JSX/TypeScriptC#
PerformanceLight weight with great performance.WASM client-side apps have a heavier first-time load. Server-side highly performant
Learning CurveEasy to LearnEasy to Learn
PWA (Progressive Web App) SupportYesYes (Blazor WebAssembly)
RoutingNot includedYes
Http ClientNot includedYes
Dependency InjectionNot includedYes
Requires an active connection per clientNoYes
Stores the component state server-side for each clientNoYes (Blazor Server)
Scoped styles for componentsYesYes
Static DeploymentYesYes (Blazor WebAssembly)
Server-Side RenderingYesYes
Optimized for SEO / CrawlersYesYes
Bundle Size12KB gzipped, but only a client render framework, not full stack.Minimal for Blazor Server.  As low as 393kb, up to 780kb  for .NET Framework in a Client-side WASM app.
ToolingCLI plus many 3rd party options.CLI, Visual Studio and 3rd party options.
Production ReadyReact is production-ready today with years of battle-tested deployments from companies such as Uber, Drop Box, Twitter, Paypal, Netflix, Walmart, and more.Yes, considering the major enhancements release in November 2021 with NET 6.

Ultimately, the choice between Blazor and React will depend on the specific requirements of your project, the skillset of your development team, and the available resources and tools. Both frameworks have their strengths and use cases, and choosing the right one for your project will require careful consideration and evaluation.

Blazor Vs Angular JS

Blazor and Angular are two popular web development frameworks that can be used to build modern web applications. Blazor is a web framework developed by Microsoft that allows developers to build interactive web applications using C# instead of JavaScript, while Angular is a JavaScript framework for building dynamic, single-page web applications.

One of the main differences between Blazor and Angular is the language used to build applications. Blazor uses C#, while Angular uses TypeScript, which is a superset of JavaScript. This means that developers who are already familiar with C# may find it easier to work with Blazor, while those who are more experienced with JavaScript may prefer to use Angular.

Another difference between Blazor and Angular is the way they handle user interface rendering. Blazor uses a server-side rendering model, where the HTML for the user interface is generated on the server and sent to the client, while Angular uses a client-side rendering model, where the HTML is generated on the client-side using JavaScript.

Ultimately, the choice between Blazor and Angular will depend on the specific requirements of your project, the skillset of your development team, and the available resources and tools. Both frameworks have their strengths and use cases, and choosing the right one for your project will require careful consideration and evaluation.