diff --git a/index.html b/index.html
index 607fd74..0d29e21 100644
--- a/index.html
+++ b/index.html
@@ -1,127 +1,558 @@
 <!DOCTYPE html>
 <html lang="en">
 <head>
-    <meta charset="UTF-8">
-    <title>image2cpp</title>
-    <style type="text/css">
-        body{
-            font-family: arial;
-        }
-        .wrapper{
-            width: 800px;
-            margin: auto;
-        }
-        .numberInput{
-            width: 50px;
-        }
-        label{
-            width: 220px;
-            display: inline-block;
-            font-weight: bold;
-        }
-        label.smallLabel{
-            width: auto;
-        }
-        td{
-            text-align: left;
-            vertical-align: top;
-        }
-        td.or{
-            padding: 20px;
-            width: 100px;
-            font-size: 30px;
-            /*vertical-align: center;*/
-        }
-        hr{
-            height: 3px;
-            background-color: black;
-            border: none;
-        }
-        img.inlineImg{
-            display: inline-block;
-        }
-        textarea.fullWidth{
-            width: 100%;
-            height: 100px;
-        }
-        table{
-            width: 100%;
-        }
-        h1{
-            margin: 0;
-        }
-    </style>
+	<meta charset="UTF-8">
+	<title>image2cpp</title>
+	<style type="text/css">
+		body{
+			font-family: arial;
+		}
+		.wrapper{
+			width: 800px;
+			margin: auto;
+		}
+		.numberInput{
+			width: 50px;
+		}
+		label{
+			width: 220px;
+			display: inline-block;
+			font-weight: bold;
+		}
+		label.smallLabel{
+			width: auto;
+		}
+		td{
+			text-align: left;
+			vertical-align: top;
+		}
+		td.or{
+			padding: 20px;
+			width: 100px;
+			font-size: 30px;
+			/*vertical-align: center;*/
+		}
+		hr{
+			height: 3px;
+			background-color: black;
+			border: none;
+		}
+		img.inlineImg{
+			display: inline-block;
+		}
+		textarea.fullWidth{
+			width: 100%;
+			height: 100px;
+		}
+		table{
+			width: 100%;
+		}
+		h1{
+			margin: 0;
+		}
+	</style>
 </head>
 <body>
-    <div class="wrapper">
-        <h1>image2cpp</h1>
-        <p>
-        <table>
-            <tr>
-                <td>
-                    <h2>1. Select image</h2>
-                    <input type="file" id="fileInput" name="fileinput"/><br />
-                    <label>Selected image size:</label> <span id="imageSize">no image selected</span>
-                </h4>
-                <td class="or">or</td>
-                <td>
-                    <h2>1. Paste byte array</h2>
-                    <textarea id="textInput" class="fullWidth"></textarea><br />
-                    <button onclick="handleTextInput('horizontal')">Read as horizontal</button>
-                    <button onclick="handleTextInput('vertical')">Read as vertical</button>
-                </td>
-            </tr>
-        </table>
-        </p>
-        <hr />
+	<div class="wrapper">
+		<h1>image2cpp</h1>
+		<p>
+		<table>
+			<tr>
+				<td>
+					<h2>1. Select image</h2>
+					<input type="file" id="fileInput" name="fileinput"/><br />
+					<label>Selected image size:</label> <span id="imageSize">no image selected</span>
+				</h4>
+				<td class="or">or</td>
+				<td>
+					<h2>1. Paste byte array</h2>
+					<textarea id="textInput" class="fullWidth"></textarea><br />
+					<button onclick="handleTextInput('horizontal')">Read as horizontal</button>
+					<button onclick="handleTextInput('vertical')">Read as vertical</button>
+				</td>
+			</tr>
+		</table>
+		</p>
+		<hr />
 
-        <p>
-            <h2>2. Image Settings</h2>
-            <label>Canvas size: </label> <input id="screenWidth" class="numberInput" type="text" name="screenWidth" onchange="updateInteger('screenWidth')" value="128"/> * <input id="screenHeight" class="numberInput" type="text" name="screenHeight" onchange="updateInteger('screenHeight')" value="64"/> pixels<br />
-            <label>Background color:</label>
-            <input id="backgroundColorWhite" type="radio" name="backgroundColor" value="white" checked="checked" onchange="updateRadio('backgroundColor')"/><label for="backgroundColorWhite" class="smallLabel">White</label>
-            <input id="backgroundColorBlack" type="radio" name="backgroundColor" value="black" onchange="updateRadio('backgroundColor')"/><label for="backgroundColorBlack" class="smallLabel">Black</label><br />
-            <label>Brightness threshold: </label> <input id="threshold" class="numberInput" type="text" name="threshold" onchange="updateInteger('threshold')" value="128"/> <i>0 - 255; pixels with brightness above become white, below become black.</i><br/>
-            <label for="scale">Scaling</label>
-            <select id="scale" name="scale" onchange="updateInteger('scale')">
-                <option value="1">original size</option>
-                <option value="2">scale to fit, keeping proportions</option>
-                <option value="3">stretch to fill canvas</option>
-                <option value="4">stretch to fill canvas horizontally</option>
-                <option value="5">stretch to fill canvas vertically</option>
-            </select><br />
+		<p>
+			<h2>2. Image Settings</h2>
+			<label>Canvas size: </label> <input id="screenWidth" class="numberInput" type="text" name="screenWidth" onchange="updateInteger('screenWidth')" value="128"/> * <input id="screenHeight" class="numberInput" type="text" name="screenHeight" onchange="updateInteger('screenHeight')" value="64"/> pixels<br />
+			<label>Background color:</label>
+			<input id="backgroundColorWhite" type="radio" name="backgroundColor" value="white" checked="checked" onchange="updateRadio('backgroundColor')"/><label for="backgroundColorWhite" class="smallLabel">White</label>
+			<input id="backgroundColorBlack" type="radio" name="backgroundColor" value="black" onchange="updateRadio('backgroundColor')"/><label for="backgroundColorBlack" class="smallLabel">Black</label><br />
+			<label>Brightness threshold: </label> <input id="threshold" class="numberInput" type="text" name="threshold" onchange="updateInteger('threshold')" value="128"/> <i>0 - 255; pixels with brightness above become white, below become black.</i><br/>
+			<label for="scale">Scaling</label>
+			<select id="scale" name="scale" onchange="updateInteger('scale')">
+				<option value="1">original size</option>
+				<option value="2">scale to fit, keeping proportions</option>
+				<option value="3">stretch to fill canvas</option>
+				<option value="4">stretch to fill canvas horizontally</option>
+				<option value="5">stretch to fill canvas vertically</option>
+			</select><br />
 
-            <label for="centerHorizontally">Center horizontally</label><input id="centerHorizontally" type="checkbox" onchange="updateBoolean('centerHorizontally')" /><br />
-            <label for="centerVertically">Center vertically</label><input id="centerVertically" type="checkbox" onchange="updateBoolean('centerVertically')" /><br />
-            <i>Centering the image only works when using a canvas larger than the selected image.</i><br />
-            <label for="invertColors">Invert image colors</label><input id="invertColors" type="checkbox" onchange="updateBoolean('invertColors')" />
-        </p>
+			<label for="centerHorizontally">Center horizontally</label><input id="centerHorizontally" type="checkbox" onchange="updateBoolean('centerHorizontally')" /><br />
+			<label for="centerVertically">Center vertically</label><input id="centerVertically" type="checkbox" onchange="updateBoolean('centerVertically')" /><br />
+			<i>Centering the image only works when using a canvas larger than the selected image.</i><br />
+			<label for="invertColors">Invert image colors</label><input id="invertColors" type="checkbox" onchange="updateBoolean('invertColors')" />
+		</p>
 
-        <hr />
+		<hr />
 
-        <p>
-            <h2>3. Preview</h2>
-            <canvas id="imageCanvas" style="border: 1px solid black;" width="128" height="64"></canvas>
-        </p>
+		<p>
+			<h2>3. Preview</h2>
+			<canvas id="imageCanvas" style="border: 1px solid black;" width="128" height="64"></canvas>
+		</p>
 
-        <hr />
+		<hr />
 
-        <p>
-            <h2>4. Output</h2>
-            <label for="addArduinoCode">Add Arduino code</label><input id="addArduinoCode" type="checkbox" onchange="updateBoolean('addArduinoCode')" /><br />
-            <i>Adds some extra Arduino code around the output for easy copy-paste into <a href="https://github.com/javl/image2cpp/blob/master/oled_example/oled_example.ino" target="_blank">this example</a>.</i><br />
-            <br />
-            <label>Draw mode:</label>
-            <input id="drawModeHorizontal" type="radio" name="drawMode" value="horizontal" checked="checked" onchange="updateRadio('drawMode')"/><label for="drawModeHorizontal" class="smallLabel">Horizontal</label>
-            <input id="drawModeVertical" type="radio" name="drawMode" value="vertical" onchange="updateRadio('drawMode')"/><label for="drawModeVertical" class="smallLabel">Vertical</label><br />
-            <i>If your image looks all messed up on your display, like the image below, try the other mode.</i><br />
-            <br />
-            <img class="inlineImg" src="img/error.jpg" width="150" height="64" alt="" /><br /><br />
-            <button type="button" onclick="outputString()">Generate code</button><br /><br />
-            <textarea id="outputField" class="fullWidth"></textarea>
-        </p>
-    </div>
-    <script type="text/javascript" src="script.js"></script>
+		<p>
+			<h2>4. Output</h2>
+			<label for="addArduinoCode">Add Arduino code</label><input id="addArduinoCode" type="checkbox" onchange="updateBoolean('addArduinoCode')" /><br />
+			<i>Adds some extra Arduino code around the output for easy copy-paste into <a href="https://github.com/javl/image2cpp/blob/master/oled_example/oled_example.ino" target="_blank">this example</a>.</i><br />
+			<br />
+			<label>Draw mode:</label>
+			<input id="drawModeHorizontal" type="radio" name="drawMode" value="horizontal" checked="checked" onchange="updateRadio('drawMode')"/><label for="drawModeHorizontal" class="smallLabel">Horizontal</label>
+			<input id="drawModeVertical" type="radio" name="drawMode" value="vertical" onchange="updateRadio('drawMode')"/><label for="drawModeVertical" class="smallLabel">Vertical</label><br />
+			<i>If your image looks all messed up on your display, like the image below, try the other mode.</i><br />
+			<br />
+			<img class="inlineImg" src="img/error.jpg" width="150" height="64" alt="" /><br /><br />
+			<button type="button" onclick="outputString()">Generate code</button><br /><br />
+			<textarea id="outputField" class="fullWidth"></textarea>
+		</p>
+	</div>
+	<script type="text/javascript">
+
+		// Add events to the file input button
+		var fileInput = document.getElementById('fileInput');
+		fileInput.addEventListener('click', function(){this.value = null;}, false);
+		fileInput.addEventListener('change', handleImageSelection, false);
+
+
+		// Filetypes accepted by the file picker
+		var fileTypes = ['jpg', 'jpeg', 'png', 'bmp', 'gif'];
+
+
+		// The canvas we will draw on
+		var canvas = document.getElementById('imageCanvas');
+		var ctx = canvas.getContext('2d');
+
+
+		// The variable to hold our image. Global so we can easily reuse it when the
+		// user updates the settings (change canvas size, scale, invert, etc)
+		var img = new Image();
+
+
+		// A bunch of settings used when converting
+		var settings = {
+			screenWidth: 128,
+			screenHeight: 64,
+			scaleToFit: true,
+			preserveRatio: true,
+			centerHorizontally: false,
+			centerVertically: false,
+			backgroundColor: "white",
+			scale: '1',
+			drawMode: 'horizontal',
+			threshold: 128,
+			addArduinoCode: false,
+			invertColors: false
+		};
+
+
+		// Easy way to update settings controlled by a textfield
+		function updateInteger(fieldName){
+			settings[fieldName] = document.getElementById(fieldName).value;
+			place_image();
+		}
+
+
+		// Easy way to update settings controlled by a checkbox
+		function updateBoolean(fieldName){
+			settings[fieldName] = document.getElementById(fieldName).checked;
+			place_image();
+		}
+
+
+		// Easy way to update settings controlled by a radiobutton
+		function updateRadio(fieldName){
+			var radioGroup = document.getElementsByName(fieldName);
+			for (var i = 0; i < radioGroup.length; i++) {
+				if (radioGroup[i].checked) {
+					settings[fieldName] = radioGroup[i].value;
+				}
+			}
+			place_image();
+		}
+
+
+		// Make the canvas black and white
+		function blackAndWhite(){
+			var imageData = ctx.getImageData(0,0,canvas.width, canvas.height);
+			var data = imageData.data;
+			for (var i = 0; i < data.length; i += 4) {
+				var avg = (data[i] + data[i +1] + data[i +2]) / 3;
+				avg > settings['threshold'] ? avg = 255 : avg = 0;
+				data[i]     = avg; // red
+				data[i + 1] = avg; // green
+				data[i + 2] = avg; // blue
+			}
+			ctx.putImageData(imageData, 0, 0);
+		};
+
+
+		// Invert the colors of the canvas
+		function invert() {
+			var imageData = ctx.getImageData(0,0,canvas.width, canvas.height);
+			var data = imageData.data;
+			for (var i = 0; i < data.length; i += 4) {
+				data[i]     = 255 - data[i];     // red
+				data[i + 1] = 255 - data[i + 1]; // green
+				data[i + 2] = 255 - data[i + 2]; // blue
+			}
+			ctx.putImageData(imageData, 0, 0);
+		};
+
+
+		// Draw the image onto the canvas, taking into account color and scaling
+		function place_image(){
+
+			// Make sure we're using the right canvas size
+			canvas.width = settings['screenWidth'];
+			canvas.height = settings['screenHeight'];
+
+			// Invert background if needed
+			if (settings['invertColors']){
+				settings['backgroundColor'] == 'white' ? ctx.fillStyle = 'black' : ctx.fillStyle = 'white';
+			}else{
+				ctx.fillStyle = settings['backgroundColor'];
+			}
+			ctx.fillRect(0, 0, canvas.width, canvas.height);
+
+			// Offset used for centering the image when requested
+			var offset_x = 0;
+			var offset_y = 0;
+
+			switch(settings['scale']){
+				case '1': // Original
+					if(settings['centerHorizontally']){ offset_x = (canvas.width - img.width) / 2; }
+					if(settings['centerVertically']){ offset_y = (canvas.height - img.height) / 2; }
+					ctx.drawImage(img, 0, 0, img.width, img.height,
+						offset_x, offset_y, img.width, img.height);
+				break;
+				case '2': // Fit (make as large as possible without changing ratio)
+					var horRatio = canvas.width / img.width;
+					var verRatio =  canvas.height / img.height;
+					var useRatio  = Math.min(horRatio, verRatio);
+
+					if(settings['centerHorizontally']){ offset_x = (canvas.width - img.width*useRatio) / 2; }
+					if(settings['centerVertically']){ offset_y = (canvas.height - img.height*useRatio) / 2; }
+					ctx.drawImage(img, 0, 0, img.width, img.height,
+						offset_x, offset_y, img.width * useRatio, img.height * useRatio);
+				break;
+				case '3': // Stretch x+y (make as large as possible without keeping ratio)
+					ctx.drawImage(img, 0, 0, img.width, img.height,
+						offset_x, offset_y, canvas.width, canvas.height);
+				break;
+				case '4': // Stretch x (make as wide as possible)
+					offset_x = 0;
+					if(settings['centerVertically']){ offset_y = (canvas.height - img.height) / 2; }
+					ctx.drawImage(img, 0, 0, img.width, img.height,
+						offset_x, offset_y, canvas.width, img.height);
+				break;
+				case '5': // Stretch y (make as tall as possible)
+					if(settings['centerHorizontally']){ offset_x = (canvas.width - img.width) / 2; }
+					offset_y = 0;
+					ctx.drawImage(img, 0, 0, img.width, img.height,
+						offset_x, offset_y, img.width, canvas.height);
+				break;
+			}
+			// Make sure the image is black and white
+			blackAndWhite();
+			if(settings['invertColors']){
+				invert();
+			}
+		}
+
+
+		// Handle inserting an image by pasting code
+		function handleTextInput(drawMode){
+
+			var input = document.getElementById('textInput').value;
+
+			// Remove Arduino code
+			input = input.replace(/const unsigned char myBitmap \[\] PROGMEM = \{/g, "");
+			input = input.replace(/\};/g, "");
+
+			// Remove newlines
+			input = input.replace(/\r\n|\r|\n/g, "");
+			// Remove whitespace
+			input = input.replace(/\s/g, "");
+			// Remove "0x"
+			input = input.replace(/0x/g, "");
+			// Split into list
+			var list = input.split(",");
+
+			if(drawMode == 'horizontal'){
+				listToImageHorizontal(list);
+			}else{
+				listToImageVertical(list);
+			}
+		}
+
+
+		// Handle selecting an image with the file picker
+		function handleImageSelection(e){
+			var reader = new FileReader();
+			reader.onload = function(event){
+				// Crude check to see if the uploaded file is an image
+				if (reader.result.substring (0, 10) != "data:image"){
+					alert("Please select an image file.");
+					return false;
+				}
+
+				img.onload = function(){
+					// Show the size underneath the file picker
+					document.getElementById('imageSize').innerHTML = img.width+" * " + img.height + " pixels";
+
+					// Resize the canvas and update the input fields
+					document.getElementById('screenWidth').value = img.width;
+					document.getElementById('screenHeight').value = img.height;
+					settings['screenWidth'] = img.width;
+					settings['screenHeight'] = img.height;
+
+					place_image();
+				}
+				img.src = event.target.result;
+			}
+			reader.readAsDataURL(e.target.files[0]);
+		}
+
+
+		// Output the image as a string for horizontally drawing displays
+		function imageToStringHorizontal(){
+			var imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
+
+			var output_string = "";
+			var output_index = 0;
+
+			var byteIndex = 7;
+			var number = 0;
+
+			for (var index=0; index < imageData.data.length; index+=4){
+				var avg = (imageData.data[index] + imageData.data[index +1] + imageData.data[index +2]) / 3;
+				if (avg > settings['threshold']){
+					number += Math.pow(2, byteIndex);
+				}
+				byteIndex--;
+
+				if(byteIndex < 0){
+					var byteSet = number.toString(16);
+					if (byteSet.length == 1){ byteSet = "0"+byteSet; }
+					var b = "0x"+byteSet;
+					output_string += b+", ";
+					output_index++;
+					if (output_index >= 16){
+						output_string += "\n";
+						output_index = 0;
+					}
+					number = 0;
+					byteIndex = 7;
+				}
+			}
+			return output_string;
+		}
+
+
+		// Output the image as a string for vertically drawing displays
+		function imageToStringVertical(){
+			var x = 0;
+			var y = 7;
+			var page = 0;
+
+			var imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
+			var data = imageData.data;
+
+			var output_string = "";
+			var output_index = 0;
+
+
+			for (var p=0; p<Math.ceil(settings['screenHeight']/8);p++){
+				for (var x=0;x<=settings['screenWidth'];x++){
+				// for (var x=0;x<1;x++){
+					var byteIndex = 7;
+					var number = 0;
+
+					for (var y = 7; y >= 0; y--){
+						var index = ((p*8)+y)*(settings['screenWidth']*4)+x;
+						var avg = (data[index] + data[index +1] + data[index +2]) / 3;
+						if (avg > settings['threshold']){
+							number += Math.pow(2, byteIndex);
+						}
+						byteIndex--;
+					}
+					var byteSet = number.toString(16);
+					if (byteSet.length == 1){ byteSet = "0"+byteSet; }
+					var b = "0x"+byteSet.toString(16);
+					output_string += b+", ";
+					output_index++;
+					if (output_index >= 16){
+						output_string += "\n";
+						output_index = 0;
+					}
+				}
+			}
+			return output_string;
+		}
+
+
+		// Output the image string to the textfield
+		function outputString(){
+			var output_string = "";
+			if (settings['drawMode'] == 'horizontal'){
+				output_string = imageToStringHorizontal();
+			}else{
+				output_string = imageToStringVertical();
+			}
+
+			if(settings['addArduinoCode']){
+				output_string = "const unsigned char myBitmap [] PROGMEM = {\n" + output_string + "\n};";
+			}
+			document.getElementById('outputField').value = output_string;
+		}
+
+
+		// Use the horizontally oriented list to draw the image
+		function listToImageHorizontal(list){
+
+			ctx.clearRect(0, 0, canvas.width, canvas.height);
+
+			var imgData = ctx.createImageData(canvas.width, canvas.height);
+
+			var index = 0;
+
+			var page = 0;
+			var x = 0;
+			var y = 7;
+
+			// Move the list into the imageData object
+			for (var i=0;i<list.length;i++){
+				var binString = hexToBinary(list[i]).result;
+				if (binString.length == 4){
+					binString = binString + "0000";
+				}
+
+				// Check if pixel is white or black
+				for(var k=0; k<binString.length; k++){
+					var color = 0;
+					if(binString.charAt(k) == '1'){
+						color = 255;
+					}
+					imgData.data[index] = color;
+					imgData.data[index+1] = color;
+					imgData.data[index+2] = color;
+					imgData.data[index+3] = 255;
+
+					index += 4
+				}
+			}
+
+			// Draw the image onto the canvas, then save the canvas contents
+			// inside the img object. This way we can reuse the img object when
+			// we want to scale / invert, etc.
+			ctx.putImageData(imgData, 0, 0);
+			img.src = canvas.toDataURL('image/png');
+		}
+
+
+		// Use the vertically oriented list to draw the image
+		function listToImageVertical(list){
+
+			ctx.clearRect(0, 0, canvas.width, canvas.height);
+
+			// Create a new imageData object, but 90 degrees rotates (height x width)
+			// var imgData = ctx.createImageData(canvas.width, canvas.height);
+			// var imgData = ctx.getImageData(0, 0, canvas.height, canvas.width);
+			//var imgData = ctx.createImageData(canvas.width, canvas.height);
+			// var data = imgData.data;
+
+			var index = 0;
+
+			var page = 0;
+			var x = 0;
+			var y = 7;
+
+			// Move the list into the imageData object
+			for (var i=0;i<list.length;i++){
+
+				var binString = hexToBinary(list[i]).result;
+				if (binString.length == 4){
+					binString = binString + "0000";
+				}
+
+				// Check if pixel is white or black
+				for(var k=0; k<binString.length; k++){
+					var color = 0;
+					if(binString.charAt(k) == '1'){
+						color = 255;
+					}
+					// color = 0;
+					drawPixel(x, (page*8)+y, color);
+					y--;
+					if(y < 0){
+						y = 7;
+						x++;
+						if(x >= settings['screenWidth']){
+							x = 0;
+							page++;
+						}
+					 }
+
+				}
+			}
+			// Save the canvas contents inside the img object. This way we can
+			// reuse the img object when we want to scale / invert, etc.
+			img.src = canvas.toDataURL('image/png');
+		}
+
+
+		// Convert hex to binary
+		function hexToBinary(s) {
+
+			var i, k, part, ret = '';
+			// lookup table for easier conversion. '0' characters are padded for '1' to '7'
+			var lookupTable = {
+				'0': '0000', '1': '0001', '2': '0010', '3': '0011', '4': '0100',
+				'5': '0101', '6': '0110', '7': '0111', '8': '1000', '9': '1001',
+				'a': '1010', 'b': '1011', 'c': '1100', 'd': '1101',
+				'e': '1110', 'f': '1111',
+				'A': '1010', 'B': '1011', 'C': '1100', 'D': '1101',
+				'E': '1110', 'F': '1111'
+			};
+			for (i = 0; i < s.length; i += 1) {
+				if (lookupTable.hasOwnProperty(s[i])) {
+					ret += lookupTable[s[i]];
+				} else {
+					return { valid: false };
+				}
+			}
+			return { valid: true, result: ret };
+		}
+
+
+		// Quick and effective way to draw single pixels onto the canvas
+		// using a global 1x1px large canvas
+		var single_pixel = ctx.createImageData(1,1);
+		var d  = single_pixel.data;
+
+		function drawPixel(x, y, color){
+			d[0] = color;
+			d[1] = color;
+			d[2] = color;
+			d[3] = 255;
+			ctx.putImageData(single_pixel, x, y);
+		}
+	</script>
 </body>
 </html>
 
