The height read-only property of the SVGFEImageElement interface describes the vertical size of an SVG filter primitive as a SVGAnimatedLength.
It reflects the height attribute of the <feImage> element, which fetches image data from an external source and provides the pixel data as output. The attribute is a <length> or a <percentage> relative to the height of the filter region. The default value is 100%. The property value is a length in user coordinate system units.
const feImage = document.querySelector("feImage");
const verticalSize = feImage.height;
console.log(verticalSize.baseVal.value); // the `height` valueSVGFEImageElement.width<blend-mode> data typemix-blend-mode property