ImageMagick is a software that allows the edition and manipulation of a multitude image formats.
In the market there are a wide variety of programs that allow us to modify images using an user interface. This is obviously very useful, although there are times when we want to make modifications to the images without having to make the changes manually. That is to say, sometimes we want to change the images by running a series of commands in the terminal of our Operating System.
ImageMagick is composed by a series of commands that allows the manipulation of the image files. Thanks to these commands, we can convert the format of the images (e.g., from GIF to PNG), crop, reduce/enlarge, rotate, combine multiple images, insert text, and many more actions.
To install the program, we need to download the package appropriate to our operating system (Windows, Linux or Mac). Once it has been installed, we need to access to the terminal and type in “convert”. All the options of the program will be displayed. As we can observe there are many options, so we will need to make use of some tutorial, or buy one of the books, which explains in detail the use of this program.
Because it is a program that runs from the command line, it probably that we need to install it as a requirement of other software. That is to say, it is possible that when we install one program, it requires to install ImageMagick in our PC.
For the programmers there are libraries in different programming languages (Python, Java, Ruby, PHP, C, etc.), that allow us to incorporate the functions of image manipulation of this software, in the programming routines.
In addition to the “convert” command, which is the main program's command, and that allows us to make any type of manipulations on images, there are 2 other commands that we will be able to use:
identify: this command shows information about the graphic file. For example if we run “identify photo.png”, it will display the information about the file “photo.png”. This information includes: resolution, size (bytes), format, depth of color, and more.
display: this command opens the image file indicated. In addition, it also allows us to apply a series of effects, and modifications on the image: rotations; modification of the brightness, saturation; grayscale, zoom, add frame, reduce noise, and more.
To run this command we must type in the terminal: “display picture.png”.
We need to keep in mind that in Windows this command is called “imdisplay”.
The possibilities offered by this software to manipulate images are virtually endless, so learning to manage this software is something that will take time and dedication. So we don't recommend this program for those users who don't have some experience with the command line of the system, or don't have enough patience to learn how to use the commands of this program, since this program has not been developed with the intention of offering an advanced graphical interface where we can apply all the functionalities of the software.
The software is free and open source.