images.Process

This filter has the same options as the Process method on a Resource object, but using it as a filter may be more effective if you need to apply multiple filters to an image.

The process specification is a space-delimited, case-insensitive list of one or more of the following in any sequence:

action

Specify zero or one of crop, fill, fit, or resize. If you specify an action you must also provide dimensions. See details.

{{ $filter := images.Process "resize 300x" }}

dimensions

Required if you specify an action. Provide width or height when using resize, else provide both width and height. See details.

{{ $filter := images.Process "crop 200x200" }}

anchor

Use with the crop or fill action. Specify zero or one of TopLeft, Top, TopRight, Left, Center, Right, BottomLeft, Bottom, BottomRight, or Smart. Default is Smart. See details.

{{ $filter := images.Process "crop 200x200 center" }}

rotation

Typically specify zero or one of r90, r180, or r270. Also supports arbitrary rotation angles. See details.

{{ $filter := images.Process "r90" }}
{{ $filter := images.Process "crop 200x200 center r90" }}

target format

Specify zero or one of gif, jpeg, png, tiff, or webp. See details.

{{ $filter := images.Process "webp" }}
{{ $filter := images.Process "crop 200x200 center r90 webp" }}

quality

Applicable to JPEG and WebP images. Optionally specify qN where N is an integer in the range [0, 100]. Default is 75. See details.

{{ $filter := images.Process "q50" }}
{{ $filter := images.Process "crop 200x200 center r90 webp q50" }}

hint

Applicable to WebP images and equivalent to the -preset flag for the cwebp encoder. Specify zero or one of drawing, icon, photo, picture, or text. Default is photo. See details.

{{ $filter := images.Process "webp" "icon" }}
{{ $filter := images.Process "crop 200x200 center r90 webp q50 icon" }}

background color

When converting a PNG or WebP with transparency to a format that does not support transparency, optionally specify a background color using a 3-digit or a 6-digit hexadecimal color code. Default is #ffffff (white). See details.

{{ $filter := images.Process "jpeg #000" }}
{{ $filter := images.Process "crop 200x200 center r90 q50 jpeg #000" }}

resampling filter

Typically specify zero or one of Box, Lanczos, CatmullRom, MitchellNetravali, Linear, or NearestNeighbor. Other resampling filters are available. See details.

{{ $filter := images.Process "resize 300x lanczos" }}
{{ $filter := images.Process "resize 300x r90 q50 jpeg #000 lanczos" }}

Usage

Create a filter:

{{ $filter := images.Process "resize 256x q40 webp" }}

Apply the filter using the images.Filter function:

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

Example

Original

Processed