https://www.babylondecoded.com/media/js/reflection.js?ref=130250

1/**
2 * reflection.js v2.0
3 * http://cow.neondragon.net/stuff/reflection/
4 * Freely distributable under MIT-style license.
5 */
6 
7/* From prototype.js */
8if (!document.myGetElementsByClassName) {
9	document.myGetElementsByClassName = function(className) {
10		var children = document.getElementsByTagName('*') || document.all;
11		var elements = new Array();
12	  
13		for (var i = 0; i < children.length; i++) {
14			var child = children[i];
15			var classNames = child.className.split(' ');
16			for (var j = 0; j < classNames.length; j++) {
17				if (classNames[j] == className) {
18					elements.push(child);
19					break;
20				}
21			}
22		}
23		return elements;
24	}
25}
26
27var Reflection = {
28	defaultHeight : 0.5,
29	defaultOpacity: 0.5,
30	
31	add: function(image, options) {
32		Reflection.remove(image);
33		
34		doptions = { "height" : Reflection.defaultHeight, "opacity" : Reflection.defaultOpacity }
35		if (options) {
36			for (var i in doptions) {
37				if (!options[i]) {
38					options[i] = doptions[i];
39				}
40			}
41		} else {
42			options = doptions;
43		}
44	
45		try {
46			var d = document.createElement('div');
47			var p = image;
48			
49			var classes = p.className.split(' ');
50			var newClasses = '';
51			for (j=0;j<classes.length;j++) {
52				if (classes[j] != "reflect") {
53					if (newClasses) {
54						newClasses += ' '
55					}
56					
57					newClasses += classes[j];
58				}
59			}
60
61			var reflectionHeight = Math.floor(p.height*options['height']);
62			var divHeight = Math.floor(p.height*(1+options['height']));
63			
64			var reflectionWidth = p.width;
65			
66			if (document.all && !window.opera) {
67				/* Fix hyperlinks */
68                if(p.parentElement.tagName == 'A') {
69	                var d = document.createElement('a');
70	                d.href = p.parentElement.href;
71                }  
72                    
73				/* Copy original image's classes & styles to div */
74				d.className = newClasses;
75				p.className = 'reflected';
76				
77				d.style.cssText = p.style.cssText;
78				p.style.cssText = 'vertical-align: bottom';
79			
80				var reflection = document.createElement('img');
81				reflection.src = p.src;
82				reflection.style.width = reflectionWidth+'px';
83				reflection.style.display = 'block';
84				reflection.style.height = p.height+"px";
85				
86				reflection.style.marginBottom = "-"+(p.height-reflectionHeight)+'px';
87				reflection.style.filter = 'flipv progid:DXImageTransform.Microsoft.Alpha(opacity='+(options['opacity']*100)+', style=1, finishOpacity=0, startx=0, starty=0, finishx=0, finishy='+(options['height']*100)+')';
88				
89				d.style.width = reflectionWidth+'px';
90				d.style.height = divHeight+'px';
91				p.parentNode.replaceChild(d, p);
92				
93				d.appendChild(p);
94				d.appendChild(reflection);
95			} else {
96				var canvas = document.createElement('canvas');
97				if (canvas.getContext) {
98					/* Copy original image's classes & styles to div */
99					d.className = newClasses;
100					p.className = 'reflected';
101					
102					d.style.cssText = p.style.cssText;
103					p.style.cssText = 'vertical-align: bottom';
104			
105					var context = canvas.getContext("2d");
106				
107					canvas.style.height = reflectionHeight+'px';
108					canvas.style.width = reflectionWidth+'px';
109					canvas.height = reflectionHeight;
110					canvas.width = reflectionWidth;
111					
112					d.style.width = reflectionWidth+'px';
113					d.style.height = divHeight+'px';
114					p.parentNode.replaceChild(d, p);
115					
116					d.appendChild(p);
117					d.appendChild(canvas);
118					
119					context.save();
120					
121					context.translate(0,image.height-1);
122					context.scale(1,-1);
123					
124					context.drawImage(image, 0, 0, reflectionWidth, image.height);
125	
126					context.restore();
127					
128					context.globalCompositeOperation = "destination-out";
129					var gradient = context.createLinearGradient(0, 0, 0, reflectionHeight);
130					
131					gradient.addColorStop(1, "rgba(255, 255, 255, 1.0)");
132					gradient.addColorStop(0, "rgba(255, 255, 255, "+(1-options['opacity'])+")");
133		
134					context.fillStyle = gradient;
135					context.rect(0, 0, reflectionWidth, reflectionHeight*2);
136					context.fill();
137				}
138			}
139		} catch (e) {
140	    }
141	},
142	
143	remove : function(image) {
144		if (image.className == "reflected") {
145			image.className = image.parentNode.className;
146			image.parentNode.parentNode.replaceChild(image, image.parentNode);
147		}
148	}
149}
150
151function addReflections() {
152	var rimages = document.myGetElementsByClassName('reflect');
153	for (i=0;i<rimages.length;i++) {
154		var rheight = null;
155		var ropacity = null;
156		
157		var classes = rimages[i].className.split(' ');
158		for (j=0;j<classes.length;j++) {
159			if (classes[j].indexOf("rheight") == 0) {
160				var rheight = classes[j].substring(7)/100;
161			} else if (classes[j].indexOf("ropacity") == 0) {
162				var ropacity = classes[j].substring(8)/100;
163			}
164		}
165		
166		Reflection.add(rimages[i], { height: rheight, opacity : ropacity});
167	}
168}
169
170var previousOnload = window.onload;
171window.onload = function () { if(previousOnload) previousOnload(); addReflections(); }