Class: Image2ASCII

Inherits:
Object
  • Object
show all
Defined in:
lib/image2ascii.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(uri) ⇒ Image2ASCII

Returns a new instance of Image2ASCII.



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# File 'lib/image2ascii.rb', line 13

def initialize(uri)
    @uri = uri
    @winsize = IO.console.winsize[1]
    @chars = %($@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\\|()1{}[]?-_+~<>i!lI;:,"^`'.).reverse
    #quantum conversion factor for dealing with quantum depth color values
    @qcf = 1 
    
    if Magick::MAGICKCORE_QUANTUM_DEPTH > 16
        raise "ImageMagick quantum depth is set to #{Magick::MAGICKCORE_QUANTUM_DEPTH}. It needs to be 16 or less"
    elsif Magick::MAGICKCORE_QUANTUM_DEPTH == 16
        #divides quantum depth color space into useable rgb values
        @qcf = 257
    end
end

Instance Attribute Details

#chars ⇒ Object

Returns the value of attribute chars.



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# File 'lib/image2ascii.rb', line 11

def chars
  @chars
end

#winsize ⇒ Object (readonly)

Returns the value of attribute winsize.



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# File 'lib/image2ascii.rb', line 10

def winsize
  @winsize
end

Instance Method Details

#generate(args = {}) ⇒ Object 



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# File 'lib/image2ascii.rb', line 28

def generate(args={})

    args[:width]   ||= @winsize
    args[:color]   ||= "full"
    args[:hidden]  ||= false
    args[:block]   ||= false
    as_string = ""

    #load the image
    resource = URI.open(@uri)
    img = Magick::ImageList.new
    img.from_blob(resource.read)

    #correct aspect ratio
    img = img.scale(args[:width] / img.columns.to_f)
    img = img.scale(img.columns, img.rows / 2)

    img.each_pixel do |pixel, col, row|

        #get RGB values and brightness of pixels
        r = pixel.red / @qcf
        g = pixel.green / @qcf
        b = pixel.blue / @qcf
        brightness = (0.2126*r + 0.7152*g + 0.0722*b)
        #select from chars that are already pre-ordered in brightness
        char_index = brightness / (255.0 / @chars.length)
        char = @chars[char_index.floor]
        as_string << char

        chosen_color =
        if args[:color] == "full"
            [r, g, b]
        elsif args[:color] == "greyscale"
            [brightness, brightness, brightness]
        else
            args[:color]
        end

        if args[:block]
            print Rainbow(" ").background(*chosen_color) if !args[:hidden]
        else
            print Rainbow(char).color(*chosen_color) if !args[:hidden]
        end

        #add line wrap once desired width is reached
        if (col % (args[:width] - 1) == 0) and (col != 0)
            print "\n" if !args[:hidden]
            as_string << "\n"
        end

    end

    return as_string
end