Finding RGB Value - Conditional

JavaScript
1

When red is less than the RGB value it is supposed to document.write “Y”. Why does it not work, please?

<html><body>
<img id="rabbit" src="https://clipartstation.com/wp-content/uploads/2017/11/rabbits-clipart-4.gif"  width="220" height="277">
<canvas id="myCanvas" width="220" height="277" style="border:1px solid #d3d3d3;"></canvas>

<script>
document.getElementById("rabbit").onload = function() {
  var c = document.getElementById("myCanvas");
  var ctx = c.getContext("2d");
  var img = document.getElementById("rabbit");
  ctx.drawImage(img, 0, 0);
  var imgData = ctx.getImageData(0, 0, c.width, c.height);  
  
var imgData = ctx.getImageData(30, 30, 50, 50);
red = imgData.data[0];
green = imgData.data[1];
blue = imgData.data[2];
alpha = imgData.data[3];

  var i;
  for (i = 0; i < imgData.data.length; i += 4) {
    imgData.data[i] = 255 - imgData.data[i];
   if (red < 214) { document.write("Y") }  // Writes "Y" when RGB is 214
    imgData.data[i+1] = 255 - imgData.data[i+1];
    imgData.data[i+2] = 255 - imgData.data[i+2];
    imgData.data[i+3] = 255;
  }
};
</script>
</body></html>
3

OK, thanks. I just read a little about cross-origin data on third-party sites. But how do I fix it, please?

5

You can fix it add this line in your js below var img
img.crossOrigin = “Anonymous”;

6

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