docs-v2/layouts/shortcodes/img-hd.html

{{ .Inner }}
{{ $src := .Get "src" }}
{{ $alt := .Get "alt" }}

{{ if (fileExists ( print "/static" $src )) }}
  {{ with (imageConfig ( print "/static" $src )) }}
    {{ $imageWidth := div .Width 2 }}
    <img src='{{ $src }}' alt='{{ $alt }}' width='{{ $imageWidth }}' />
  {{ end }}
{{ else }}
  <img src='{{ $src }}' alt='{{ $alt }}'/>
{{ end }}