ImageRuby - flexible ruby gem for image processing

ImageRuby is a gem for image processing written in pure ruby, this makes the library very portable and easy to install

Also, the gem was desgined to accept extensions like:

* new format decoders made from scratch (Ruby or C)
* new format decoders based on existent C libraries like libpng, libbmp, etc...
* new image operations (Ruby or C)
* re-implementations of parts in C to improve performance on environments where it is possible

Installation

Gem installation

sudo gem install imageruby

Documentation

Full API documentation can be found on: tario.github.com/imageruby/doc/

Examples

NOTE: Examples loads and saves bitmap files, imageruby-bmp gem must be installed in order to get the examples work

Create and save a black image

require "rubygems"
require "imageruby"

include ImageRuby

#  creates an image of 150x150 pixels filled with black
image = ImageRuby::Image.new(150,150, Color.black)

begin
# this only work if imageruby-bmp gem is installed
image.save("black.bmp", :bmp)
rescue
  print "Error while trying to save, you must install imageruby-bmp gem"
end

Create an image with vertical stripes filled with default named colors

require "rubygems"
require "imageruby"

include ImageRuby

print "list of named colors:\n"
print "--------------------------\n"

colors = Array.new

Color.named_colors.each do |name, color|

print “#name: #colorcolor.inspectn” colors << color

end

image = Image.new( colors.count * 32, 512)

x = 0
colors.each do |color|
image[x..x+31, 0..511] = Image.new(32,512,color)
x = x + 32
end

image.save("colors.bmp", :bmp)

Gradient using block parameter

require "rubygems"
require "imageruby"

include ImageRuby

gradient_images = Array.new

gradient_images << Image.new(64,64) {|x,y| 
  Color.from_rgb(x*4,y*4,0) 
}

gradient_images << Image.new(64,64) {|x,y| 
  Color.from_rgb(0,x*4,y*4) 
}

gradient_images << Image.new(64,64) {|x,y| 
  Color.from_rgb(y*4,0,x*4) 
}

(0..gradient_images.count-1).each do |i|

gradient_images.save(“gradient#i.bmp”, :bmp)

end

all_gradient = Image.new(96*gradient_images.count, 96)

(0..gradient_images.count-1).each do |i|

all_gradient.draw!(i*96+16, 16, gradient_images)

end

all_gradient.save("gradients.bmp", :bmp)

Draw with mask

require "rubygems"
require "imageruby"

include ImageRuby

colors = Image.from_file("colors.bmp")
gradients = Image.from_file("gradients.bmp")

without_mask = colors.draw(128,192,gradients)
without_mask.save("without_mask.bmp", :bmp)

with_mask = colors.draw(128,192,gradients.mask(Color.black))
with_mask.save("with_mask.bmp", :bmp)

Draw with transparency effects

require "rubygems"
require "imageruby"

include ImageRuby

colors = Image.from_file("colors.bmp")
gradients = Image.from_file("gradients.bmp")

transparent_black = Color.black
transparent_black.a = 128

colors.draw(128,192,gradients.color_replace(Color.black, transparent_black)).save("sample1.bmp", :bmp)

half_transparent = gradients.map_pixel{ |x,y,c|

c.a = 128 if x >144 c

}
colors.draw(128,192,half_transparent).save("sample2.bmp", :bmp)

Copying

Copyright © 2011 Dario Seminara, released under the GPL License (see LICENSE)