curtail

Curtail

Curtail is a pure JavaScript image manipulation tool.

Note: This documentation is for Curtail 3.0, the most recent version of Curtail which reflects some API changes.

Installation

To download Curtail through npm, simply use the following command:

$ npm install curtail

Curtail doesn't have a named export so you can import the specific modules you need or all of them like so:

import * as curtail from './node_modules/curtail/curtail.js';

Modules

The available modules within Curtail are:

• Transform: The transform methods are used to change the image size, format, and other 'physical' properties.

  • crop: Crops an image to a specified dimensions from a starting point.
  • convert: Converts an image from one format to another.
  • resize: Resizes an image with the option of keeping the aspect ratio.

• Decorate: Contains methods that to add decorative features to images.

  • pad: Adds a padding of your color around the image. It could also be thought of as a border.

Transform

The transform methods are used to change the image size, format, and other 'physical' properties.

Note: As loading of images is an asynchoronous action, all of Curtail's methods return a Promise which you can use either then or await as shown in the examples below.

crop

The crop method takes the path to an image, a crop start location, and the final dimensons of the image and returns the newly cropped version of the original image.

param	type	description	default
path	string	The path to the image to crop
x	number	The horizontal starting location of the crop
y	number	The vertical starting location of the crop
width	number	The width of the cropped image
height	number	The height of the cropped image
options	Object		{}
options.autoDownload	boolean	Indicates whether the image should download after the cropping is complete or not.	false
options.crossOrigin	string	Sets the cross-origin property of images originating from external sources.	null

Using Promise.then:

// This will take an image and start cropping at (100, 100) and create a new image
// with a width of 720x480.
curtail.crop('./path/to/image.png', 100, 100, 720, 480).then((newImage) => {

  // newImage will be your newly cropped image and if autoDownload is set to true
  // then you will have a local copy downloaded at this time.

});

Using async/await:

async function main() {

  // This will take an image and start cropping at (100, 100) and create a new image
  // with a width of 720x480.
  // You should probably use `try, catch`
  const newImage = curtail.crop('./path/to/image.png', 100, 100, 720, 480).catch((err) => console.log(err));

  // newImage will be your newly cropped image and if autoDownload is set to true
  // then you will have a local copy downloaded at this time.

}

main();

convert

The convert method takes an image and converts it from one image format to another.

If you have a transparent image and convert it to a format that doesn't support transparency, the image will be placed on a white background.

param	type	description	default
path	string	The path to the image to crop
format	string	The new format for the image
options	Object		{}
options.autoDownload	boolean	Indicates whether the image should download after the cropping is complete or not.	false
options.crossOrigin	string	Sets the cross-origin property of images originating from external sources.	null

Using Promise.then:

// This will take an image and start cropping at (100, 100) and create a new image
// with a width of 720x480.
curtail.convert('./path/to/image.png', 'jpg').then((newImage) => {

  // newImage will be your newly converted image and if autoDownload is set to true
  // then you will have a local copy downloaded at this time.

});

Using async/await:

async function main() {

  // This will take an image and start cropping at (100, 100) and create a new image
  // with a width of 720x480.
  // You should probably use `try, catch`
  const newImage = curtail.convert('./path/to/image.png', 'jpg').catch((err) => console.log(err));

  // newImage will be your newly converted image and if autoDownload is set to true
  // then you will have a local copy downloaded at this time.

}

main();

resize

The resize method takes an image and resizes it, maintaining its aspect ratio by default.

param	type	description	default
path	string	The path to the image to crop
format	string	Which dimension to resize, either width or height. Keep in mind that if you're preserving the aspect ratio, the other will resize accordingly
size	number	The new size to make the specified dimension
options	Object		{}
options.preserveAspectRatio	boolean	Indicates whether the width and height will resize together to preserve the aspect ratio of the image	true
options.autoDownload	boolean	Indicates whether the image should download after the cropping is complete or not.	false
options.crossOrigin	string	Sets the cross-origin property of images originating from external sources.	null

Using Promise.then:

// This will take an image (sized 1920x0180 in this example) and resize the width to
// be 400 which will result in the image having a width of 400 and height of 225.
curtail.resize('./path/to/image.png', 'width', 400).then((newImage) => {

  // newImage will be your newly resized image and if autoDownload is set to true
  // then you will have a local copy downloaded at this time.

});

Using async/await:

async function main() {

  // This will take an image (sized 1920x0180 in this example) and resize the width to
  // be 400 which will result in the image having a width of 400 and height of 225.
  // You should probably use `try, catch`
  const newImage = curtail.resize('./path/to/image.png', 'width', 400).catch((err) => console.log(err));

  // newImage will be your newly resized image and if autoDownload is set to true
  // then you will have a local copy downloaded at this time.

}

main();

Decorate

Contains methods to add decorative features to images.

pad

The pad method takes an image and adds the specified amount of padding to it.

param	type	description	default
path	string	The path to the image to crop
padding	number	The amount of padding to add to the image
options	Object		{}
options.paddingColor	string	The color that the padding will be. This value can be any valid CSS color value such as white or #FFFFFF	'transparent'
options.autoDownload	boolean	Indicates whether the image should download after the cropping is complete or not.	false
options.crossOrigin	string	Sets the cross-origin property of images originating from external sources.	null

Using Promise.then:

// This will take an image and add 20px of blue padding to all sides.
curtail.pad('./path/to/image.png', 20, { paddingColor: 'blue' }).then((newImage) => {

  // newImage will be your newly padded image and if autoDownload is set to true
  // then you will have a local copy downloaded at this time.

});

Using async/await:

async function main() {

  // This will take an image and add 20px of blue padding to all sides.
  // You should probably use `try, catch`
  const newImage = curtail.pad('./path/to/image.png', 20, { paddingColor: 'blue' }).catch((err) => console.log(err));

  // newImage will be your newly padded image and if autoDownload is set to true
  // then you will have a local copy downloaded at this time.

}

main();

License

MIT

Changelog

3.1.5 / 2019-11-14

• [MISC] Updated the interfaces from references to imports.
• [MISC] Removed unnecessary jsdoc comments.