An Architect plugin for transforming images

What it does

Drop large images in the static folder of an Architect app and request a transformed version.

Install

You can install the plugin for any Architect app with npm install @enhance/arc-image-plugin. You can then add it to your app manifest like this:

#app.arc
@app
image-app

@plugins
enhance/arc-image-plugin

Use

The Architect framework serves static assets from a local folder that becomes an S3 bucket when deployed to AWS. You drop your giant.jpeg image in the public folder, and then once deployed, you can access it from anywhere. In your app you can request http://example.com/_static/giant.jpeg or with a root relative path at /_public/giant.jpeg.

With the image plugin, you can request the same image by swapping the “_static” for “transform” and include query parameters to get a different size (/transform/width_100,height_100/giant.jpeg). This will scale the image to fit in those dimensions while maintaining the aspect ratio.

Other examples:

• /transform/format_avif,width_100,quality_50/_public/elephant.jpg
• /transform/format_webp,width_100,height_500/_public/elephant.png

Supported formats

• png
• jpeg
• avif
• webp
• jxl
• gif

Parameters

• quality: specify the quality setting for lossy formats.
• format: The requested image format for the output.
• width: Output width
• height: Output height
• fit: type of placement
  • 'contain'(default): output will fit inside the specified height and width
  • 'cover': output will cover the height and width with the remaining portion cropped.
• focus: If the image is cropped what area is maintained as the focal point.
  • Options: 'top', 'right', 'bottom', 'left', 'top-right', 'bottom-right', 'bottom-left', 'top-left', 'center', 'point'
  • Default: 'center'
• mark: adds a marker to the chosen focal point of the image to temporarily identify the focal point.
  • Use with focus=point, x=, and y=
• x,y: Mark a focal point from the top left by percentage. Used with focus=point

The transformation maintains aspect ratio.

The first time a request is made, it is transformed in a lambda and that new version is saved to an S3 bucket. The next request for that size is served from the cache.