opticrop-node

node.js port of jueseph/Opticrop

Detect the most interesting part of picture and crops it

tested on node v7.7.4

Description

Unlike most cropping routines out there, Opticrop uses edge-detection to find the most “interesting” part of the image to crop, so you won’t get a useless thumbnail just because the top-left corner of your image happened to be a big patch of featureless sky.

Limitations

Opticrop was written to be smarter than easily available alternatives, but because the strategy is relatively simple, it still makes the “wrong” crop on certain images.

read more

Example #1 - crops original image just fine

Example #2 - the result is perfect

Example #3 - result is not as good as you probably expected

Installation

First install graphicsmagick and dev version od GD2 (more info here)

on Debian/Ubuntu

sudo apt-get install graphicsmagick
sudo apt-get install libgd2-xpm-dev
OR
sudo apt-get install libgd2-dev # libgd
npm install opticrop-node

On RHEL/CentOS

$ sudo yum install gd-devel
npm install opticrop-node

on Mac OS/X

brew install graphicsmagick
brew install pkg-config gd
npm install opticrop-node

Will not build on Windows!

Example

cropTo returns bluebird Promise if callback param is not passed down

const Opticrop = require('opticrop-node').Opticrop;
const opticrop = new Opticrop;
opticrop
  .setImage(inFile)
  .setWidth(100)
  .setHeight(100)
  .cropTo(outFile)
  .then(() => {
    console.log('crop is done')
  })
  .catch((err) => {
    console.log("Error", err);
  });

or it accepts a callback as last argument

const Opticrop = require('opticrop-node').Opticrop;
const opticrop = new Opticrop;
opticrop
.setImage('./images/example.jpg')
  .setWidth(100)
  .setHeight(100)
  .cropTo('./images/cropped_example.jpg', (err, data) => {
    console.log("Cropping done", err, data);
  });

Test

Following command will crop example images and save as images/cropped_example.(gif|jpg|png)

node test.js

You also can check if there are memory leaks

TEST_MEMORY=1 node test.js

Version History

1.0.0

Rewritten in TypeScript

0.1.2

Updated installation instructions 0.1.1

Cropping speed was increased by 3 times due to replacing of mikolalysenko/get-pixels with mikesmullin/node-gd

0.1.0

Ported version of jueseph/Opticrop