@knovator/image-resizer

Express middleware for resizing images.
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Table of Contents

1. About The Project
   • Built With
2. Getting Started
   • Installation
3. Usage
4. Roadmap
5. Contributing
6. License
7. Contact

About The Project

• @knovator/image-resizer is an express middleware that generates images of size and format passed in URL using sharp package.
• @knovator/image-resizer takes input of public folder path and when it receives a request it checks if the requested image exists in the public folder. If it doesn't, it generates the image in resolution folder.
• resolution is passed in the URL as width and height parameters. For example, in /images/1200x850/image.jpg URL 1200 is width and 850 is height. It accepts resolution from 2 digits to 6 digits..
• Image generation done in following setps:
  • Check if the image exists in the public folder by removing resolution. For example
    • /images/800x800/image.jpg will be checked in /images/image.(jpg|png|webp|jpeg).
  • If the image doesn't exist, it generates the image in specified resolution folder.
• It also generates images of different format in resolution folder if the image of that format is not exists.
  • For example /images/800x800/image.jpg image request will be generated as /images/800x800/image.jpg by taking /images/image.(jpg|png|webp|jpeg) as input.

It's required to use resize middleware before using express.static middleware.

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Built With

• sharp
• glob

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Getting Started

@knovator/image-resizer is built as an express middleware, so NodeJS application setup with expressjs is required to start.

Installation

1. Install the package

   npm i @knovator/image-resizer
   # or
   yarn add @knovator/image-resizer

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Usage

• Usage of @knovator/image-resizer is simple. It takes input of public folder path similar to express.static middleware.For example,

  const { resize } = require('@knovator/image-resizer');
  
  app.use(resize(__dirname + '/public'));

• @knovator/image-resizer considers jpg, png, webp and jpeg image formats. if you want to use other formats, you can pass it in the extensions parameter. For example,

  const { resize } = require('@knovator/image-resizer');
  
  app.use(resize(__dirname + '/public', { extensions: ['.png', '.jpg', '.jpeg', '.webp'] }));

Example in app.js file

const express = require('express');
const app = express();
const PORT = 8080;
const { resize } = require('@knovator/image-resize');

app.get('/status', (_req, res) => {
    res.send('All Okay');
});

app.use(resize(__dirname + '/public'));
app.use(express.static(__dirname + '/public'));

app.listen(PORT, () => {
    console.log(`App started on ${PORT}`);
});

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Usecases

@knovator/image-resizer is built to generate images of different resolution and format. It can be used in following usecases:

• Generate images of different resolution like 600x600, 1280x720, 1920x1080 etc.
• Generate images of different formats like webp, png, jpg etc.
• Doing image transformation on the basis of requests.
• Serving and transforming images from local folder.

If you have any other usecase, please open an issue with tag usecase. We will try to add it in our roadmap.

Roadmap

• Add test cases

See the open issues for a full list of proposed features (and known issues).

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Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

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License

Distributed under the MIT License. See LICENSE.txt for more information.

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Contact

Knovator Technologies

• Twitter @knovator
• Web https://knovator.com/