Recently, Google announced that page speed is certainly a ranking factor for websites in the search engine sector. This article explains the image compression as one of the speed optimization techniques.

How image compression affects speed optimization?

Speed optimization is a measure to understand the loading time for a website from the hosting server. There are two major benefits of a fast website –

  • The speed of the website is a ranking factor. The speedy website offers a better rank
  • Users are more comfortable working with plain and fast loading website. Speed optimization is a foremost factor for a good website.

Usually, Webmasters/developers create attractive images using Photoshop software. However, Photoshop created image file sizes are bigger. These images are of megabytes size and thus it will take more time to download the website. So image compression technique is helpful to reduce the image size and will ultimately reduce the website loading time. Webp is a modern image format developed by Google for faster and smaller images format on the web.

How to work with Webp?

Webp modern image format gives you a supreme lossless and lossy image compression. Web developers can create a smaller yet beautiful image using Webp.

The lossy images created using Webp are 25 to 34 % smaller compare to JPEG image format; while Webp lossless images are 26% smaller than PNG image format. For both images, the SSIM quality index remains the same.

Webp Working Mechanism:

To reconstruct new pixels, the lossless Webp compression uses already seen image fragments. The local palette can be also used for this lossless Webp compression.

The predictive coding technique has been used by the Lossy Webp compression to encode an image. This technique is similar to the VP8 video codec technique used to compress the key frames in videos. This coding method uses neighboring pixel blocks values to predict the values in a block and only difference will be encoded.

Webp image format features:

 

  • Lossless and Lossy compression – The Lossless compression has been developed by Webp developer’s team and VP8 key frame encoding is a base of Lossless compression. VP8 is nothing but a video compression format successor to the VP6 and VP7.
  • Transparency – Both Lossy and Lossless Webp format support transparency (known as an 8-bit alpha channel). Transparency is very useful in graphical images.
  • Animation – Webp format supports true color animated images
  • Metadata support – Webp image format supports EXIF and XMP metadata
  • Color Format – Webp image format supports Embedded ICC profile

Webp image format is supported in Google Chrome, opera, and Firefox browser as well in the android system. It comprises of the lightweight encoding and decoding library libwebp as well as command line tools cwebp, dwebp for image conversion for webp format. You can perform muxing, viewing and animating operations on Webp images. You can download a precompiled cwebp tool to convert your image collection in PNG and JPEG to Webp format.

To summarize, Webp is a modern image format developed by Google that is optimized to enable smaller and faster images on the web. Webmasters can use this image compression technique for speed optimization of the website and reduce the loading time of the website.