ch-arham/image-optimization

Image Optimization Techniques like blurhash and more to reduce the load time of a website

Introduction

As you work on websites with high image usage you encounter load time issues. You will probably try to reduce the load time by:

• Optimizing the code, and images.
• Minifying CSS.
• Server Side Rendering etc

But still there will be something missing. I provide solutions for that something .

Introducing Images Optimizing by Lazy Loading and Blur Image showing until the original loads techniques.

1. Clone the project.

2. Preferably use Node version 16.17.1

3. run command: yarn or npm install

4. Run the project: yarn dev or npm run dev

5. Uncomment the different solutions to see their working in the App.jsx file.

6. Inspect --> Network --> Set Throttling to Fast 3G and select img filter.

Note: By default Solution One is shown.

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Solution One

This is implemented using custom JSX, CSS, and JS. This is flexible and can be customised any way seen fit.

1. By default images have loading attribute set to eager. You can change this to loading='lazy' to trigger the lazy loading on images. (Yes, it is as simple as that).
2. Generate a blur version of the images to be used.
3. Stacked the blur image on top of the original. Original image is hidden and only shows when it is completely loaded. Then this is shown instead of the blur image.
4. Custom js is written to check for the loading of images and apply custom css.
5. Shows a pulse animation and fade effect when image is loaded.
6. use this commad to generate blur images: ffmpeg -i imageName.jpg -vf scale=10:-1 imageNameSmall.jpg scale = number tells the pixels -1 tells to maintain the aspect ratio

You can set the scale to however you see fit or use any other approach to generate a blur version of the original image.

For mac users you can get the ffmeg by using brew. For windows and linux follow online guidelines.

Solution Two

This Solution uses the blur hash technique

1. For each image generate blur hash from the blur hash website or use their encoder and decoder.
2. Store the image URL/path and blur hash in an object together
3. Install blurhash react package and use it to decode the blur hash.
4. When the original image is loaded show original image instead of blur hash image.

There are draw backs to this approach.

Although it is very convenient to have the URL and blur hash in the database and simply fetching and displaying them but the blur image does not perfectly align with the actual image

On different screens this issue can be seen so the only solution to this is:

Set width and height for different screen sizes and match it with the blurhash width and height

Solution Three

This solution uses the lazysizes library

The best way to describe this library is that they use the same approach as the solution one.

It is highly optimised and cross browser compatible.

Check their doc to learn more lazysizes

Other Solutions

1. **This solution uses the React Lazy Load Image Component **

https://www.npmjs.com/package/react-lazy-load-image-component

Note: Width and height on images are required for the browser to be able to calculate the viewport