Introduction

Do you need to convert BMP images to a JPEG format? Or a JPEG image to a BMP format? This article will walk you through how to do that quickly and easily using Node.js and the Jimp NPM package.

Jimp is an image processing library written in JavaScript with zero native dependencies. It allows you to do a ton of cool stuff with images in an easy manner.

Let's get started!

Table of Contents

Install Jimp NPM Package

First, you need to install the npm package. You can install it with either the NPM or Yarn command below:

NPM:
    
      npm install jimp --save
    
  
Yarn:
    
      yarn add jimp
    
  

Now we're ready to start writing some code and converting images!

Convert BMP to JPEG

Let's convert a .bmp file to a .jpg format first. Make sure you have a .bmp file in the root of your project directory that you want to convert to a .jpg file.

Here's the full code:

    
      const Jimp = require("jimp")

      Jimp.read("image.bmp", function (err, image) {
        if (err) {
          console.log(err)
        } else {
          image.write("new-image.jpg")
        }
      })
    
  

Let's break down each part of the code:

  1. First, we import the jimp NPM package and hold it in the Jimp variable.
  2. Then, we use the Jimp.read() function to process the image into something we can work with. We pass the path of the image.bmp file to the function. And the function returns a promise with an error (if it exists) and an image to work with.
  3. We do some error handling inside the callback function.
  4. Then, we write the new new-image.jpg file to the current directory with the image.write() function.

When you run the code, you'll see the new JPEG file in your directory.

Make sense? Cool! Let's move onto the next example in the next section.

Convert JPEG to BMP

Now let's convert a .jpg file to a .bmp format. Make sure you have a .jpg file in the root of your project directory that you want to convert to a .bmp.

Here's the full code:

    
      const Jimp = require("jimp")

      Jimp.read("image.jpg", function (err, image) {
        if (err) {
          console.log(err)
        } else {
          image.write("new-image.bmp")
        }
      })
    
  

Here's the break down each part of the code:

  1. First, we import the jimp NPM package and hold it in the Jimp variable.
  2. Then, we use the Jimp.read() function to process the image into something we can work with. We pass the path of the image.jpg file to the function. And the function returns a promise with an error (if it exists) and an image to work with.
  3. We do some error handling inside the callback function.
  4. Then, we write the new new-image.bmp file to the current directory with the image.write() function.

And you should see the new BMP file in your directory after running the code.

Conclusion

Now you know how to convert back and forth between JPEG and BMP files using Node.js and Jimp!

Thanks for reading and happy coding!