Compress PNG Image Files Using Ruby

This code snippet uses MiniMagick to open a PNG image, reduce its quality to 50 and save the compressed image with a new file name.

require 'mini_magick'

# open the input file
input_file = MiniMagick::Image.open('input.png')

# compress the image with quality 50
input_file.quality(50)

# save the output file
input_file.write('output.png')

Let's break down each part of the code:

1. require 'mini_magick': This line imports the MiniMagick gem into your Ruby script. MiniMagick is a popular Ruby library for interacting with the ImageMagick command-line tools, which allows you to manipulate images programmatically.
2. input_file = MiniMagick::Image.open('input.png'): This line opens an image file named 'input.png' using MiniMagick and assigns it to the variable input_file. This step essentially loads the image into memory, making it accessible for further processing.
3. input_file.quality(50): Here, you are specifying a quality setting of 50 for the image. This quality setting applies to image formats like JPEG, where you can control the compression level by adjusting the quality. A lower quality value (e.g., 50) typically results in a smaller file size but may also reduce the image's visual quality.
4. input_file.write('output.png'): Finally, this line saves the modified image, which has been compressed with the specified quality setting, as 'output.png'. The write method is used to save the image with the specified changes.