var manCanvas = new ManipulateCanvas(canvas);

// get pixel with the coordinate (x, y)

manCanvas.getPixel(x, y);

//change pixel with coordinate (x, y) to the white pixel

manCanvas.setPixel(x, y, [255, 255, 255, 255]);

var manCanvas = new ManipulateCanvas(canvas);

// change to grayscale

manCanvas.grayscale()

// change brigthness and contrast

manCanvas.brigthness(intensity)

manCanvas.contrast(intensity)