濃度変換

fの中身を弄ると色々出力が変わるあれ。

require "cglib.rb"

# image file
img_file = "img.bmp"

# convert function
def f(n)
	n = 1 * n # to fixnum

	if n % 8 == 0 then
		return n
	else
		return 255 - n
	end
end

# create objects
form = Forms::Form.new
form.width  = 500
form.height = 500

pictures = [Forms::PictureBox.new, Forms::PictureBox.new]
pictures[0].image = Drawing::Image::FromFile(img_file)
pictures[1].left  = pictures[0].image.width + 10

pictures.map {|pic|
	pic.width  = pictures[0].image.width
	pic.height = pictures[0].image.height
}

button = Forms::Button.new
button.top = pictures[0].image.height + 10

graph = Forms::PictureBox.new
graph.width     = 256
graph.height    = 256
graph.top       = pictures[0].image.height + 10
graph.left      = form.width - 265
graph.backColor = Drawing::Color.black

# convert
button.click {|sender, args|
	# draw convert picture
	pictures[1].image = Drawing::Bitmap.new(pictures[0].width, pictures[1].height)
	pictures[1].Refresh

	pictures[0].image.width.times {|x|
		pictures[0].image.height.times {|y|
			pixel = pictures[0].image.getPixel(x, y)
			color = Drawing::Color::fromArgb(f(pixel.r), f(pixel.g), f(pixel.b))
			pictures[1].image.setPixel(x, y, color)
		}
	}

	pictures[1].Refresh

	# draw graph
	graphic = graph.createGraphics
	graph.Refresh

	pre_p = [0, f(0)]

	256.times {|i|
		graphic.drawLine(Drawing::Pens.red, pre_p[0], pre_p[1], i, 255 - f(i))
		pre_p = [i, 255 - f(i)]
	}

	graphic.Dispose
}

# add controls
pictures.concat([button, graph]).map {|cntrl|
	form.controls.add(cntrl)
}

# show form
form.showDialog()

cglib.rbってのは

require 'mscorlib'
require 'System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
require 'System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'

Forms = System::Windows::Forms

Drawing = System::Drawing
Drawing2D = System::Drawing::Drawing2D

とか書いてあるだけ。