Compress JPEG Image Files Using Ruby

This code snippet opens a JPEG image, reduces its quality to 50 (which increases compression and reduces file size) and then saves the compressed image with the same filename.

require 'mini_magick'

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

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

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

Let's break down each part of the code:

require 'mini_magick'

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

• This line includes the MiniMagick gem in your Ruby script.
• It then opens an image file named 'input.jpg' using MiniMagick and assigns it to the variable input_file. This step loads the JPEG image into memory for further processing.

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

• This line sets the quality of the opened JPEG image to 50. In JPEG compression, the quality parameter typically ranges from 0 to 100, with higher values indicating better quality but larger file sizes. Lower values, such as 50, result in greater compression and smaller file sizes but may reduce image quality.

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

• Finally, this line saves the modified JPEG image, which has been compressed with a quality setting of 50, as 'output.jpg'. The write method is used to save the image with the specified changes.