How to edit images with C++ and ImageMagick

The Magick++ API is the object-oriented C++ API for the ImageMagick image processing library.

Magick++ supports an object model inspired by PerlMagick . Images support implicit reference counting so that copy constructors and assignment incur almost no cost.

The cost of copying an image (if necessary) is done right before modification and this copy is managed automatically by Magick++. Dereferenced copies are automatically deleted. Image objects support value (rather than pointer) semantics, so it is trivial to support multiple generations of an image in memory at the same time.

In this article we will see 4 examples of use!

Installation on Ubuntu and Windows

Installation on Ubuntu:

sudo apt install imagemagick libmagick++-dev graphicsmagick-libmagick-dev-compat

To install on Windows or other distros and operating systems, see the links below:

Example 01 - Create an image and draw and paint a circle in the center

#include <Magick++.h>

int main(){
   Magick::InitializeMagick("");

   Magick::Image image(Magick::Geometry(800, 600), Magick::Color("white"));

   Magick::DrawableCircle circle(400, 300, 500, 300);
   image.fillColor("green");
   image.draw(circle);
   image.write("green_circle.png");

   return 0;
}

To compile and run:

g++ `Magick++-config --cxxflags --cppflags` -O2 -o 01 main.cpp `Magick++-config --ldflags --libs`)
./01

Example 02 - Crop region of an image

Image used in example 02: langs.png

#include <Magick++.h>

int main(){
   Magick::InitializeMagick("");

   Magick::Image image;

   image.read("./langs.png");

   image.crop(Magick::Geometry(219, 147, 409, 272));

   image.write("php.jpg");

   return 0;
}

Example 03 - Convert WEBP image to JPG

Image used in example 03: The-man-image.webp

#include <Magick++.h>

int main(){
   Magick::InitializeMagick("");

   Magick::Image image;

   image.read("./The-man-image.webp");

   image.write("Bjarne Stroustrup.jpg");

   return 0;
}

Example 04 - Drawing text on the image

Font used: font.ttf

#include <Magick++.h>

int main(){
   Magick::InitializeMagick("");

   Magick::Image image;

   image.read("./Bjarne Stroustrup.jpg");
   image.font("./font.ttf");
   image.fillColor(Magick::Color("yellow"));
   image.strokeColor(Magick::Color("black"));
   image.fontPointsize(30);

   image.draw(Magick::DrawableText(50, 300, "Bjarne Stroustrup"));

   image.write("image_com_texto.png");

   return 0;
}