In this article, I will explain how to watermark images using Jimp, a powerful image-processing library for Node.js.

Before we dive into the details, let me first define what a watermark is. A watermark is a text or image that is superimposed on an image to protect its copyright and ownership. Watermarks are used by photographers, graphic designers, and other creators to protect their work from unauthorized use.

Jimp is a JavaScript image processing library that allows you to perform various operations on images, such as resizing, cropping, and adding watermarks. To get started, you will need to install Jimp on your system. You can do this by running the following command in your terminal:

npm install jimp

Once you have installed Jimp, you can start using it to add watermarks to your images. Here's a step-by-step guide to help you get started:

Step 1: Load the image

The first step is to load the image you want to watermark using the Jimp library. You can do this by creating a new instance of the Jimp class and passing the path of the image file as an argument. Here's an example:

const Jimp = require('jimp');

async function waterMarker(){
const readImage = Jimp.read('path/to/image.jpg')
const watermarkText = "Watermark Text";    
const angleOfRotation = 45;

    try {


    const font = await jimp.loadFont(jimp.FONT_SANS_64_WHITE)

// Creates a blank black image        
const image2 = new jimp(read.bitmap.width, read.bitmap.height, "black")
// Applies the watermark across the width and lenght of the image
        for (let i = 0; i < read.bitmap.height; i +=         (font.info.size * (watermarkText.length + 1))) {
            for (let j = 0; j < read.bitmap.width; j += (font.info.size * 2)) {
                image2.print(font, i, j, watermarkText) }        }
        image2.blur(3).rotate(angleOfRotation).opacity(0.3)
        read
            .composite(image2, 0, 0)
            .write(`path/to/image.png`)


    } catch (err) {
      console.log(err.message)
}

In this example, we're creating a new instance of the Jimp class to create a black rectangle with a width and height equal to that of the original image. We're then using the print() method to add the text "Watermark Text" to the watermark. We're using the loadFont() method to load the default sans-serif font with a size of 64 pixels, and we're centering the text horizontally and vertically using the alignmentX and alignmentY options.

We're then using the composite() method of the Jimp class to overlay the watermark onto the original image. The composite() method takes the watermark image, the x and y coordinates where you want to place the watermark, and the mode you want to use to blend the images together.

And that is it.

Hurray! You have just created your water marking algorithm!

1. You know only a fraction until you know design patterns that guarantee maintainability for your use case.
2. Clean code takes time to write but its worth it in the long run.
3. Too much freedom is a bad practice on its own. A third party should only be able to interact with your software in the way and only the way you want them to.

1. Single-Line Commenting ( // )

2. Multi-Line Commenting ( /**/ )

3. Documentation Commention ( /// )

Single Line Commenting (//): as the name implies is used when you comment on just a single line of your file. For example:

void main(List<String> args){
This is not a comment
// This is a Single Line comment
Single Line Comments do not extend to the next line
}

But in some cases, you want to add many lines of comment because it makes your comment more human-readable. For this, some people will decide to use multiple single-line comments.

void main(List<String> args){
// This is a Single Line comment
// This is another Single Line comment
// This is the third Single Line comment
}

But Dart provides us with another Syntax for this (Multi-Line Comment).

void main(List<String> args){

/* This is another Multi Line comment
It extends to the next line.
*/
}

This way, you can write more lines of comment and express yourself more clearly without loosing the purpose of writing comments in the first place - clarity. The third way of commenting Dart provides us with is (Documentation Commenting). This is very helpful for people who write codes that are accessed on public domains. For example:

void main(List<String> args){
add(2,3);
}

///This Function returns the sum of two numbers
int add(int firstNumber, int secondNumber){
    return firstNumber+ secondNumber;
}

Some functions and classes in Dart programming language won't be easily understood if they weren't properly documented. By the way, you don't need to worry about the codes you just typed, the purpose of this lecture is to expose you what commenting is, what it does and how it is used in Dart programming language.

public class HelloWorld{
      public static void main(String[] args){
          System.out.println("Hello World");
      }    
}

In the above snippet, I first create a public class called HelloWorld then within the class, I created another static method called main, then within the main, I called the function System.out.println("Hello World"). Dart provides us with a lot easier syntax. All you need to do is:

void main(List<String> args){
  print("Hello World");
}

First, you create a main function, and then within the main, you call the function print("Hello World"). You don't need to worry about understanding what you are writing for now. The goal of this lecture is to get you to write your first line of Dart Code. Then in your Dart Pad you can click on run. Congratulations! You have written your first line of Dart Code.