Installing and Using ImageMagick for Image Processing and Conversion in Linux Command Line

ImageMagick is a tool that allows you to convert and process images from the terminal. This article introduces ImageMagick’s installation method, basic command usage, and useful techniques.

Installation Method

First, install ImageMagick. On Ubuntu, execute the following command:

sudo apt-get install imagemagick

Basic Usage

ImageMagick supports many image formats and allows you to perform various operations from the command line.

General Options

1. Change Extension

To convert an image format, use the convert command.

convert image.jpg image.png

2. Resize

You can change the size of an image. You can specify by percentage or pixels.

• Resize by Percentage

convert -resize 50% image.jpg image.png

• Resize by Pixels

convert -resize 100x200 image.jpg image.png

3. Reduce Quality

You can reduce file size by lowering the image quality.

convert -quality 1 image.jpg _image.jpg

Rotate All .jpg Images in a Folder 90 Degrees and Save as New Files

To rotate all .jpg images in a folder by 90 degrees and save them with new filenames, use loop processing as follows.

for file in *.jpg; do convert $file -rotate 90 after-$file; done

Text Embedding

You can also embed text into images. Specify the position and content of the text.

convert -draw 'text 100,100 "IMAGE"' image.jpg _image.jpg