Grayscale image: Difference between revisions

=={{header|Sidef}}==

{{trans|Perl}}

<lang ruby>require('Image::Imlib2')

func tograyscale(img) {

var (width, height) = (img.width, img.height)

var gimg = %s'Image::Imlib2'.new(width, height)

0.to(width - 1).each { |x|

0.to(height - 1).each { |y|

var (r, g, b) = img.query_pixel(x, y)

var gray = int(0.2126*r + 0.7152*g + 0.0722*b)

gimg.set_color(gray, gray, gray, 255)

gimg.draw_point(x, y)

}

}

return gimg

}

var (input='input.png', output='output.png') = @ARGV

var image = %s'Image::Imlib2'.load(input)

var gscale = tograyscale(image)

gscale.set_quality(80)

gscale.save(output)</lang>