put gradient on an image html code example

Example 1: gradient over image css

#linear-gradient-over-image{
    background-image: linear-gradient(to bottom, black, white), 
      url('images/background.jpg');
    background-size: cover;
}

Example 2: how to find the gradient linear of image

GradientFinder {
    fromUrl: function(url, onload),
    fromCanvas: function(canvas)
};