express-sharp

express-sharp adds real-time image processing routes to your express application. Images are processed with sharp, a fast Node.js module for resizing images.

Installation

$ yarn add express-sharp
$ npm install express-sharp --save

See sharp installation for additional installation instructions.

Usage

Example app.js:

'use strict'

const express = require('express')
const app = express()
const scale = require('express-sharp')

const options = {baseHost: 'mybasehost.com'}
app.use('/my-scale', scale(options))

app.listen(3000)

Render http://mybasehost.com/image.jpg with 400x400 pixels:

GET /my-scale/image.jpg?width=400 HTTP/1.1
Host: localhost:3000

--> invokes in background:
  GET image.jpg HTTP/1.1
  Host: mybasehost.com

Same as above, but with 80% quality, webp image type and with progressive enabled:

GET /my-scale/image.jpg?format=webp&quality=80&progressive=true HTTP/1.1
Host: localhost:3000

Options

const scale = require('express-sharp')
app.use('/some-path', scale(options))

Supported options:

baseHost

Specify the HTTP base host from which images will be requested.

cropMaxSize

The maximum length in pixels (width or height) a cropped Image is allowed to have. Note: if this value is too high an attacker could use this to slow down your server. Default is 2000

cors

Specify CORS options as described in cors docs. Example:

app.use('/some-path', scale({
  cors: {
    origin: 'http://example.com'
  }
}))

If not specified, a Access-Control-Allow-Origin: * header is being sent.

Path and query params

format

Output image format.

Default: webp if supported else the output format of the requested image.

Valid values: every valid sharp output format string, i.e. jpeg, gif, webp or raw.

progressive

only available for jpeg and png formats:

See sharp docs for jpeg.

See sharp docs for png.

Use &progressive=true to enable progressive scan.

quality

See sharp docs.

quality is a Number between 1 and 100.

crop

See sharp docs.

Use &crop=true to enable the sharp cropping feature.

Default is `false.

Note: Both width and height params are neccessary for crop to work.

gravity

See sharp docs.

When the crop option is activated you can specify the gravity of the cropping.

Possible attributes of the optional gravity are north, northeast, east, southeast, south, southwest, west, northwest, center and centre.

Default is center;

License

MIT