motion detection w Jimp, detection w google vision API

motion.ts

import vision from '@google-cloud/vision'
import Jimp from 'jimp';
import { unlinkSync } from 'fs';

const PHOTOS_DIR = './photos'
const MOTION_PERCENT_THRESHOLD = .005


// Maybe put this in some timed loop as imagse come in


// Camera Data
let currPhotoBuffer = {} as Buffer // your photo in a node buffer
let currPhotoJimp = {} as Jimp // can hold a Jimp object between iterations of the loop 

const checkMotionDetection: () => Promise<boolean | null> = async () => {
    /*----------- Take Photo and Motion Detection  ---------*/
    const previousPhotoJimp = currPhotoJimp
    const photoMs = Date.now()

    const photoJpgFilename = photoMs + '.jpg'

    try {
        // Read with Jimp
        currPhotoJimp = await Jimp.read(currPhotoBuffer)

        // Remove photo
        unlinkSync(PHOTOS_DIR + photoJpgFilename)

    } catch (e) {
        console.error(e)
    }


    // Calc motion
    const motionPercent = Jimp.diff(currPhotoJimp, previousPhotoJimp, .2).percent
    const hasNewMotion = motionPercent > MOTION_PERCENT_THRESHOLD

    if (hasNewMotion) {
        return true
    }

    return false

}

const analyzePhoto: () => Promise<void> = async () => {
    const visionClient = new vision.ImageAnnotatorClient()

    /*----------- Object Detection   ---------*/

    try {
        const request = {
            image: {
                content: currPhotoBuffer
            }
        }
        if (!visionClient.objectLocalization) { // appease the TS linter 
            throw Error('This should not be thrown')
        }
        const [result] = await visionClient.objectLocalization(request)
        if (!result.localizedObjectAnnotations) { 
            throw Error('Did not receive results')
        }
        const detections = result.localizedObjectAnnotations

        const detectedTagString = detections.map(detection => detection.name + ': ' + detection.score).join(', ')
        console.log('analyzed pic. Detected: ' + detectedTagString)

    } catch (e) {
        console.error(e)
    }

}