ImageData data Property - Javascript Canvas Reference

Javascript examples for Canvas Reference:ImageData

  1. HOME
  2. Javascript
  3. Canvas Reference
  4. ImageData

Description

The data property contains image data of the ImageData object.

Pixel in an ImageData object have the RGBA values:

  • R - The color red (from 0-255)
  • G - The color green (from 0-255)
  • B - The color blue (from 0-255)
  • A - The alpha channel (from 0-255) 0 is transparent and 255 is fully visible

The color/alpha information is store in an array, which is the data property of the ImageData object.

JavaScript syntax 

imageData.data;

Example

The following code shows how to create a 100*100 pixels ImageData object where every pixel is set to the color red.

Demo Code

ResultView the demo in separate window 

<!DOCTYPE html>
<html>
<body>

<canvas id="myCanvas" width="300" height="250" style="border:1px solid #d3d3d3;">
Your browser does not support the HTML5 canvas tag.</canvas>

<script>

var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
var imgData = ctx.createImageData(100, 100);

var i;//from  w  w  w . j  a v  a2s  .  c om
for (i = 0; i < imgData.data.length; i += 4) {
    imgData.data[i+0] = 255;
    imgData.data[i+1] = 0;
    imgData.data[i+2] = 0;
    imgData.data[i+3] = 255;
}

ctx.putImageData(imgData, 10, 10);

</script>

</body>
</html>

Related Tutorials