D8: Theming examples: Images: How to print individual image values and suppress width and height via the image.html.twig template ... *First results of struggling through Drupal 8 - better solutions are probably out there! **Drupal 8 is still Beta - improvements through API modifications are possible!

image.html.twig

{#
/**
 * @file
 * Default theme implementation of an image.
 *
 * Available variables:
 * - attributes: HTML attributes for the img tag.
 * - style_name: (optional) The name of the image style applied.
 *
 * @see template_preprocess_image()
 *
 * @ingroup themeable
 */
#}

{# ORIG #}
{%
set classes = [
  style_name ? 'image-style-' ~ style_name|clean_class,
]
%}
<img{{ attributes.addClass(classes) }} />

{# VALUES #}
{{ attributes.src }} {# absolute image path considering the image style #}
{{ attributes.width }}
{{ attributes.height }}
{{ attributes.alt }}
{{ attributes.class }}
{{ uri }} {# absolute image path considering the image style #}
{{ width }}
{{ height }}
{{ alt }}

{# COMPOSED EXAMPLE - cleaner would be template_preprocess_image() #}
{%
set classes = [
  style_name ? 'image-style-' ~ style_name|clean_class,
]
%} 
{% set printattributes = attributes.addClass(classes)|without('src','alt','class','width','height') %}
{% set printclass = attributes.class.value() ? 'class="' ~ attributes.class ~ '"' : '' %}
{% set printalt = alt ? 'alt="' ~ alt ~ '"' : '' %}


<img {{ printclass|passthrough }} src="{{uri}}" {{ printattributes }} {{ printalt|passthrough }} />

Thanks for this @sachbearbeiter. I've been bashing my head against the key board for hours. This totally solved my issue of needing an absolute url in images for an email template

Thanks for the feedback ...
And it's still working - fine ;)