hugo/docs/content/en/methods/resource/_common/processing-spec.md

Process specification

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

action

Applicable to the Process method only. Specify zero or one of crop, fill, fit, or resize. If you specify an action you must also provide dimensions.

dimensions

Provide width or height when using the Resize method, else provide both width and height. See details.

anchor

Use with the Crop and Fill methods. Specify zero or one of TopLeft, Top, TopRight, Left, Center, Right, BottomLeft, Bottom, BottomRight, or Smart. Default is Smart. See details.

rotation

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

target format

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

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.

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.

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.

resampling filter

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