images.Mask

Returns an image filter that applies a mask to the source image.

The images.Mask filter applies a mask to an image. Black pixels in the mask make the corresponding areas of the base image transparent, while white pixels keep them opaque. Color images are converted to grayscale for masking purposes. The mask is automatically resized to match the dimensions of the base image.

When applying a mask to a non-transparent image format such as JPEG, the masked areas will be filled with the color specified by the bgColor parameter in your [site configuration]. You can override that color with a Process image filter:

{{ $filter := images.Process "#00ff00" }}

Usage #

Create a slice of filters, one for WebP conversion and the other for mask application:

{{ $filter1 := images.Process "webp" }}
{{ $filter2 := images.Mask (resources.Get "images/mask.png") }}
{{ $filters := slice $filter1 $filter2 }}

Apply the filters using the [images.Filter] function:

{{ with resources.Get "images/original.jpg" }}
  {{ with . | images.Filter $filters }}
    <img src="{{ .RelPermalink }}" width="{{ .Width }}" height="{{ .Height }}" alt="">
  {{ end }}
{{ end }}

You can also apply the filter using the [Filter] method on a ‘Resource’ object:

{{ with resources.Get "images/original.jpg" }}
  {{ with .Filter $filters }}
    <img src="{{ .RelPermalink }}" width="{{ .Width }}" height="{{ .Height }}" alt="">
  {{ end }}
{{ end }}

Example #

Mask