image-diffr

    1.2.1 • Public • Published

    image-diffr

    Build Status Dependency Status

    A simple tool for comparing the similarity between two images. Works on PNGs and JPGs, both from the command line and as a require()able module. Responds with a weighted percentage of the differences between the images based on a threshold value, and/or generates a new image highlighting the differences between the two inputs.

    Alt text

    Inputs & Diff Result

    Alt text Alt text Alt text

    Full credit for the underlying image diff'ing/analysis goes to Jimp and related authors. This is effectively a wrapper (CLI & node module) for easy use.


    Installation

    Easy command line use:

    npm install -g image-diffr
    

    or to use as a module in another project:

    npm install --save image-diffr
    

    CLI Usage

    image-diffr ./path/to/1.png ./path/to/2.png
    

    Options

    • Threshold -t [value], --threshold [value]

      How stringent should the comparison be (0 to 1: 0 being perfect match, 1 being pretty damn lack·a·dai·si·cal).

      image-diffr ./path/to/1.png ./path/to/2.png -t 0.25
      
    • Output -o [path], --output [path]

      Output an image highlighting the differences between the two input images. The file extension you specify in the name of the output file name (.jpg below) should match the input file types.

      image-diffr ./path/to/1.png ./path/to/2.png -o /tmp/diff.jpg
      
    • Output Only If Different -d [true|false], --differentonly [true|false]

      If using the output option to render a diff of the two images to disk, should it only output if there is a difference?

    • Quit -q, --quiet

      By default, image-diffr will show a few stats (see image above) when run. To silence that business, pass -q or --quiet and it'll become this:

      Alt text

    • Help

      Invoke without any arguments

      $: image-diffr
      
      Options:
      
      -h, --help                           output usage information
      -V, --version                        output the version number
      -t, --threshold [threshold]          Diff comparison threshold (0-1, eg. 0.25)
      -o, --output [output]                Image diff output (absolute path, eg. /tmp/diff-image.jpg)
      -d, --differentonly [differentonly]  Only write output image (-o/--output flags) if different
      -q, --quiet [quiet]                  Skip detailed output and show diff percentage only
      

    Module usage

    When require()ing as a node_module, no output will be logged to stdout. There is a single method with a 3 parameter arity: .exec(imagePath1 string, imagePath2 string, options {}).

    The .exec() method returns a Promise, which resolves with a Jimp image instance. If an error occurs, be sure to catch it as shown below.

    const imageDiffr = require('image-diffr');
    const image1Path = '/path/from/root/image1.jpg';
    const image2Path = '/path/from/root/image2.jpg';
    imageDiffr
        .exec(image1Path, image2Path, {
            threshold: 0.3,
            output: '/tmp/diffedresult.jpg'
        })
        .then(diff => {
            console.log(diff.percent);
            console.log(diff.image);
        })
        .catch(err => {
            // handle error
        });
    

    Options

    • Threshold {threshold: 0.1} [optional | default: 0]

      How stringent should the comparison be (0 to 1: 0 being perfect match, 1 being pretty damn lack·a·dai·si·cal).

    • Output {output: '/path/somewhere.jpg'} [optional | default: null]

      Output an image highlighting the differences between the two input images. The file extension you specify in the name of the output file name (.jpg below) should match the input file types.

    • Output Only If Different {outputOnlyIfDifferent: true} [optional | default: true]

      If using the output option to render a diff of the two images to disk, should it only output if there is a difference?


    Running tests

    npm test
    

    License

    (The MIT License)

    Copyright (c) 2017 Fluid, Inc, Jon Hartman <jhartman@fluid.com>

    Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

    Install

    npm i image-diffr

    DownloadsWeekly Downloads

    13

    Version

    1.2.1

    License

    MIT

    Last publish

    Collaborators

    • jhartman86