is there way to compare two images using jimp for node js

Question

I am a beginner in node js, so I am looking for a way to compare two images using jimp for my project. I want to know is that possible, if it is possible the code and method of doing it, or is there another way to do that.

Answer 1

Here's an example of comparing images, we can compare using pixel distance or hamming distance.

This is very similar to an example from the Jimp docs, though we're loading the images from an online source.

You could play around with the thresholds, we're using the same here as Jimp uses in its demo.

const Jimp = require('jimp');

async function compareImages(image1Url, image2Url) {

    const image1 = await Jimp.read(image1Url);
    const image2 = await Jimp.read(image2Url);
    // Perceived distance
    const distance = Jimp.distance(image1, image2);
    // Pixel difference
    const diff = Jimp.diff(image1, image2);
    
    console.log(`compareImages: distance: ${distance.toFixed(3)}, diff.percent: ${diff.percent.toFixed(3)}`);
    if (distance < 0.15 || diff.percent < 0.15) {
        console.log("compareImages: Images match!");
        return true;
    } else {
        console.log("compareImages: Images do NOT match!");
        return false;
    }
}

const usFlag = "https://flaglane.com/download/american-flag/american-flag-small.jpg";
const canadianFlagJpg = "https://flaglane.com/download/canadian-flag/canadian-flag-small.jpg";
const canadianFlagPng = "https://flaglane.com/download/canadian-flag/canadian-flag-small.png";

// These should not match.
compareImages(usFlag, canadianFlagJpg);

// These should match.
compareImages(canadianFlagJpg, canadianFlagPng);