How to use the command 'guetzli' (with examples)
Guetzli is a JPEG image compression utility developed by Google. Its main purpose is to provide a means to compress JPEG and PNG images while maintaining high visual quality. This article will provide examples of various use cases for the ‘guetzli’ command.
Use case 1: Compress a JPEG image
Code:
guetzli input.jpg output.jpg
Motivation: The motivation for compressing a JPEG image is to reduce its file size without sacrificing image quality. This can be particularly useful when sharing images online or when storage space is limited.
Explanation:
- ‘guetzli’ is the command itself.
- ‘input.jpg’ specifies the input file path, which is the JPEG image to be compressed.
- ‘output.jpg’ specifies the output file path, where the compressed JPEG image will be saved.
Example output:
Created output.jpg with quality 84.9666
Use case 2: Create a compressed JPEG from a PNG
Code:
guetzli input.png output.jpg
Motivation: Converting a PNG image to a compressed JPEG format can be beneficial in scenarios where PNG images are not supported or larger file sizes need to be reduced.
Explanation:
- ‘guetzli’ is the command itself.
- ‘input.png’ specifies the input file path, which is the PNG image to be converted and compressed.
- ‘output.jpg’ specifies the output file path, where the compressed JPEG image will be saved.
Example output:
Created output.jpg with quality 89.0766
Use case 3: Compress a JPEG with the desired visual quality
Code:
guetzli --quality 90 input.jpg output.jpg
Motivation: The motivation for specifying the desired visual quality when compressing a JPEG image is to have control over the trade-off between image quality and file size. By adjusting the quality value, you can find the right balance for your specific needs.
Explanation:
- ‘guetzli’ is the command itself.
- ‘–quality 90’ specifies the desired visual quality for the compressed JPEG image. The value ranges from 84 to 100, with a higher value indicating better image quality but potentially larger file size.
- ‘input.jpg’ specifies the input file path, which is the JPEG image to be compressed.
- ‘output.jpg’ specifies the output file path, where the compressed JPEG image will be saved.
Example output:
Created output.jpg with quality 90.1234
Conclusion:
The ‘guetzli’ command provides a simple and effective way to compress JPEG and PNG images while preserving visual quality. By following the examples outlined in this article, you can easily utilize the command to reduce file sizes and optimize image quality for various purposes.
