Grayscale image: Difference between revisions

=={{header|Wren}}==

{{libheader|DOME}}

This script converts the image [https://rosettacode.org/File:Lenna100.jpg Lenna100.jpg] to grayscale and then displays the two images side by side.

<lang ecmascript>import "graphics" for Canvas, Color, ImageData

import "dome" for Window

class PercentageDifference {

construct new(width, height, image1, image2) {

Window.title = "Grayscale Image"

Window.resize(width, height)

Canvas.resize(width, height)

_image1 = image1

_image2 = image2

_img1 = ImageData.loadFromFile(image1)

_img2 = ImageData.create(image2, _img1.width, _img1.height)

}

init() {

toGrayScale()

// display images side by side

_img1.draw(0, 0)

_img2.draw(550, 0)

Canvas.print(_image1, 200, 525, Color.white)

Canvas.print(_image2, 750, 525, Color.white)

}

toGrayScale() {

for (x in 0..._img1.width) {

for (y in 0..._img1.height) {

var c1 = _img1.pget(x, y)

var lumin = (0.2126 * c1.r + 0.7152 * c1.g + 0.0722 * c1.b).floor

var c2 = Color.rgb(lumin, lumin,lumin, c1.a)

_img2.pset(x, y, c2)

}

}

}

update() {}

draw(alpha) {}

}

var Game = PercentageDifference.new(1100, 550, "Lenna100.jpg", "Lenna-grayscale.jpg")</lang>