ruby-opencv's Introduction

ruby-opencv

An OpenCV wrapper for Ruby.

Web site: https://github.com/ruby-opencv/ruby-opencv
Ruby 1.9.3, 2.0.0, 2.1.x and OpenCV 2.4.8 are supported.

Requirement

OpenCV http://opencv.org/
- Download
- Install guide

Install

Linux/Mac

Install OpenCV
Install ruby-opencv

$ gem install ruby-opencv -- --with-opencv-dir=/path/to/opencvdir

Note: /path/to/opencvdir is the directory where you installed OpenCV.

Windows

You can use pre-build binary for Windows (mswin32).

Install OpenCV
Set path to OpenCV libraries. When you installed OpenCV to C:\opencv, add C:\opencv\build\x86\vc10\bin to the systems path.
Install ruby-opencv

$ gem install ruby-opencv

Sample code

Load and Display an Image

A sample to load and display an image. An equivalent code of this tutorial.

require 'opencv'
include OpenCV

if ARGV.size == 0
  puts "Usage: ruby #{__FILE__} ImageToLoadAndDisplay"
  exit
end

image = nil
begin
  image = CvMat.load(ARGV[0], CV_LOAD_IMAGE_COLOR) # Read the file.
rescue
  puts 'Could not open or find the image.'
  exit
end

window = GUI::Window.new('Display window') # Create a window for display.
window.show(image) # Show our image inside it.
GUI::wait_key # Wait for a keystroke in the window.

Face Detection

A sample to detect faces from an image.

require 'opencv'
include OpenCV

if ARGV.length < 2
  puts "Usage: ruby #{__FILE__} source dest"
  exit
end

data = './data/haarcascades/haarcascade_frontalface_alt.xml'
detector = CvHaarClassifierCascade::load(data)
image = CvMat.load(ARGV[0])
detector.detect_objects(image).each do |region|
  color = CvColor::Blue
  image.rectangle! region.top_left, region.bottom_right, :color => color
end

image.save_image(ARGV[1])
window = GUI::Window.new('Face detection')
window.show(image)
GUI::wait_key