SVG Filter: width 100% height 100% does not cover image

Question

I have a simple SVG Filter. If you click the example below, that filter will appear/disappear:

var image = document.querySelector('image');

var url = 'https://i.picsum.photos/id/202/200/200.jpg?hmac=eGzhW5P2k0gzjc76Tk5T9lOfvn30h3YHuw5jGnBUY4Y';

image.setAttribute('xlink:href', url);

window.addEventListener('click', function() {
  var filter = image.getAttribute('filter')
    ? ''
    : 'url(#blur)';
  image.setAttribute('filter', filter);
})

image {
  background: red;
}

<svg width='200' height='200'>
  <filter id='blur' width='100%' height='100%'>
    <feGaussianBlur stdDeviation='2' result='blur' />
  </filter>
  <image x='0' width='200px' height='200px' xlink:href='' id='svg-image' filter='url(#blur)'  />
</svg>

I'd like the filtered image to be the same size as the unfiltered image. Does anyone know how I can accomplish this? Any pointers would be appreciated!

Answer 1

You need to set the initial dimension using x and y attribute as follows.

<filter id='blur' x='0' y='0' width='100%' height='100%'>
...

var image = document.querySelector('image');

var url = 'https://i.picsum.photos/id/202/200/200.jpg?hmac=eGzhW5P2k0gzjc76Tk5T9lOfvn30h3YHuw5jGnBUY4Y';

image.setAttribute('xlink:href', url);

window.addEventListener('click', function() {
  var filter = image.getAttribute('filter')
    ? ''
    : 'url(#blur)';
  image.setAttribute('filter', filter);
})

image {
  background: red;
}

<svg width='200' height='200'>
  <filter id='blur' x='0' y='0' width='100%' height='100%'>
    <feGaussianBlur stdDeviation='2' result='blur' />
  </filter>
  <image x='0' width='200px' height='200px' xlink:href='' id='svg-image' filter='url(#blur)'  />
</svg>