Img-diff-js NPM

img-diff-js

:art: Node.js library to compare 2 images without native libs.

Actual	Expected	Difference

Install

npm install img-diff-js

const { imgDiff } = require("img-diff-js");

imgDiff({
  actualFilename: "example/actual.png",
  expectedFilename: "example/expected.png",
  diffFilename: "example/diff.png",
}).then(result => console.log(result));

API Usage

`imgDiff(opt: ImgDiffOptions): Promise<ImgDiffResult>`

Create image differential between two images.

`ImgDiffOptions`

{
  actualFilename: string;
  expectedFilename: string;
  diffFilename?: string;
  generateOnlyDiffFile?: boolean; // default false
  options?: {
    threshold?: number;   // default 0.1
    includeAA?: boolean;  // default false
  }
}

actualFilename - Required - Path to actual image file.
expectedFilename - Required - Path to expected image file.
diffFilename - Optional - Path to differential image file. If omitted, imgDiff does not output image file.
generateOnlyDiffFile - Optional - Generate only files with difference
options - Optional - An object to pass through pixelmatch.

`ImgDiffResult`

{
  width: number;
  height: number;
  imagesAreSame: boolean;
  diffCount: number;
}

width - Differential image's width.
height - Differential image's height.
imagesAreSame - It'll be true only if 2 images are same perfectly.
diffCount - The number of differential pixels.

Available format

The following codecs are available for input image files.

png
jpeg
tiff (limited. See https://github.com/Quramy/decode-tiff#compatibility )
bmp

imgDiff detects the input image format from it's extension name. For example, if the input file name ends with ".jpeg", imgDiff attempts to decode in JPEG way regardless of the actual file format.

The output image format is PNG only.