voluptasquisquam/src/image/utility/__tests__/setChannel.js

Image processing and manipulation in JavaScript

import {Image} from 'test/common';
import 'should';

describe('get a specific channel from an image', function () {

    it('should check channels from a RGBA image', function () {
        let image = new Image(1, 2);

        let red = new Image(1, 2, [230, 100], {
            kind: 'GREY'
        });
        image.setChannel(0, red);

        let green = new Image(1, 2, [83, 140], {
            kind: 'GREY'
        });
        image.setChannel('g', green);

        let blue = new Image(1, 2, [120, 13], {
            kind: 'GREY'
        });
        image.setChannel(2, blue);

        let alpha = new Image(1, 2, [55, 77], {
            kind: 'GREY'
        });
        image.setChannel('a', alpha);

        image.components.should.equal(3);
        image.channels.should.equal(4);
        image.bitDepth.should.equal(8);
        Array.from(image.data).should.eql([230, 83, 120, 55, 100, 140, 13, 77]);
    });
});