Lesson 8Image optimization and lazy loading
- Notion 47 - The difference between raster & vector images.
- Notion 48 - Select the correct file type.
- Notion 49 - Adjust the quality of an image.
- Notion 50 - Understand image compression.
- Notion 51 - Use CSS sprites.
- Notion 52 - What’s the new WebP format?
- Notion 53 - Tools for image optimization.
- Notion 54 - Review/assessment
Notion 54
Review/assessment
Target skills
Check your understanding of the main aspects of the notion.
There are 2 types of images. The raster image and the vector image.
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The main difference between these two types of images is that the raster format can be resized without losing the quality of the image, unlike the vector format.
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The main difference between these two types of images is that the vector format can be resized without losing the quality of the image, unlike the raster format.
The format of the image does not influence the loading of your web page.
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A bad choice of format has a major impact on the loading of your web page and thus increases your energy consumption.
The Webp format combines the advantages of the three (3) other formats (JPEG, GIF, PNG). It creates smaller images that are richer with a faster impact on the web. Its compression is of better quality and is done with or without loss.
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The criteria to take into account when adjusting the quality of the images on your website are size, weight and compression.
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The method of compression known as "with loss": makes it possible to reduce the color space to the most current colors of an image.
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The CSS Sprite technique consists in assembling several images in a single file, thus reducing the number of HTTP requests.
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Image optimization consists of enlarging the file size of the images in order to have a better image quality.
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Image optimization consists of reducing the file size of images as much as possible without sacrificing quality, so that the loading time of your pages remains low. This means that your environmental impact is reduced because the download time is greatly reduced.