Wednesday, December 04, 2024
Home » Technology » What is Google guetzli JPEG Encoder and How it Works

What is Google guetzli JPEG Encoder and How it Works

  author
Written By Nimisha Ramesh
Mack John
Approved By Mack John  
Published On April 17th, 2017
Reading Time 4 Minutes Reading

Google is known as one of the champions when it comes to open source. There are many such projects and software which are made open source and helps users in many ways. Recently, Google released the new open source project which is called as Guetzli. So, in this article, we will discuss what is Google Guetzli Encoder and how it works.

What is Google Guetzli JPEG Encoder

Google Guetzli is a new open source JPED encoder which creates the high quality of JPEG image files which sizes between 29 percent and 45 percent less than what it is possible now with the available solutions. There were numerous techniques and methods for adjusting JPEG image quality and it’s size but Google Guetzli Encoder starts from the quantization stage of the compression.

Guetzli according to the Google’s Research uses the new psychovisual model which is called as Butteraugli.

Why only JPEG and not Other Image File Formats?

Google Guetzli Encoder encodes only JPEG files Because JPEG is a lossy compression method which is used for digital images which basically balances the size of the file and image quality. It is also because the JPEG image file format is the most used image file format in the industry. The encoding process of JPEG file format is the result of the process of multistage compression and they are as follows:

  • Downsampling
  • Block Splitting
  • Colour Space transformation.
  • Quantization
  • Discrete Cosine transform
  • Entropy Coding

The JPEG file format and algorithm is very popular especially on the web where every byte of the image is counted. However, there are many times where the JPEG does a great job with the images containing smooth variations of tone and colour. But JPEG file format is not at all great for line drawings or iconic graphics. In that particular situation, the lossless graphics format is used and the most popular of them all are TIFF, GIF or PNG. To perform the image acquisition, other digital negatives file formats such as NEF for Nikon, CR2 for Canon or PEF, are used for the good possible capturing of radiometric features.

Where the users can get Google Guetzli

The Guetzli source code and tool is available at Github for the users to try and download it on their system.

Plus, Google themselves has promised that the Google Guetzli JPEG Encoder can create the high-quality JPEG images with the file size 35 percent smaller than the currently available tools and methods.

How it Looks

For a normal human being, Google Guetzli Encoder has compressed samples which look better than created in libjpeg ones. According to Google, Guetzli has the worst SSIM and PSNRHVS-M than libjpeg, yet, then it is checked with Butteraugli or from direct human feedback, Guetzli outperforms all of them. In fact, the whole purpose of this JPEG encoder is to create the images for the human viewing rather than for the case of JPEG algorithms.

Conclusion

Google has released Guetzli as an open source project for everyone to check out and, just like everything related to open source and improve it’s performance while using this tool. For now, Google Guetzli JPEG Encoder is still not ready for the full-time use. Even Google have some doubts and issues whether saving the transfer time is are worth the decoding time. Yet, Guetzli has a huge opportunity and potential to reshape the web. Faster transfer times means that the web is rapid and fast and particularly in the mobile devices causes less stress on the network. Also, Google is the only player in this field. In case there is faster web it means that more ads are shown. To look at the Google Guetzli Encoder project go to the GitHub page for the same. Instructions for setting up and using the tool are provided for the respective platform and operating system.