Upload a watermark image with Jimp

index.js

'use strict'

const Jimp = require('jimp');
const AWS = require('aws-sdk');

AWS.config.update({
  region: '****',
  endpoint: '****',
  accessKeyId: '****',
  secretAccessKey: '****'
});

const s3 = new AWS.S3({
    region: '***',
    endpoint: '***'
});



const inputFileS3Url = '***';
const waterMark = {
    text: 'Watermark test text',
    alignmentX: Jimp.HORIZONTAL_ALIGN_LEFT,
    alignmentY: Jimp.VERTICAL_ALIGN_BOTTOM
}
// background image for the watermark
const watermarkBackground = '****';




printWaterMark(waterMark);

async function printWaterMark(imageCaption) {
    
    const image = await Jimp.read(inputFileUrl);
    const background = await Jimp.read(watermarkBackground);

    const imgWidth = image.bitmap.width;
    const imgHeight = image.bitmap.height;

    const font = await getFont(imgHeight);

    var textLong = Jimp.measureText(font, imageCaption.text);
    var backgroundHeight = imgHeight-(getBackgroundHeight(imgHeight));

    image.blit(background, 0, backgroundHeight, 0, 0, imgWidth, 0);
    image.print(font, 10, getBackgroundHeight(imgHeight), imageCaption, textLong, imgHeight);

    image.getBuffer(Jimp.AUTO, function(error, result){
        s3.putObject(
            {
                Bucket: '****',
                Key: '****',
                Body: result,
                ContentType: '****',
                ACL: '****'
            },
            function(err, data) {
                if (err) {
                    console.log('Failed saving to S3', err);
                }
            });

    });
}

async function getFont(imageHeight){
    var font;
    var fontHeight = Math.floor(imageHeight / 10);

    if(fontHeight <= 16){
        font = Jimp.FONT_SANS_8_WHITE;
    } else if (fontHeight >= 16 && fontHeight <= 32) {
        font = Jimp.FONT_SANS_16_WHITE;
    } else if (fontHeight >= 32 && fontHeight <= 64) {
        font = Jimp.FONT_SANS_32_WHITE;
    } else if (fontHeight >= 64 && fontHeight <= 128) {
        font = Jimp.FONT_SANS_64_WHITE;
    } else if (fontHeight > 128) {
        font = Jimp.FONT_SANS_128_WHITE;
    }

    return await Jimp.loadFont(font);
}

function getBackgroundHeight(imageHeight){
    var fontHeight = Math.floor(imageHeight / 10);

    if(fontHeight <= 16){
        return 20;
    } else if (fontHeight >= 16 && fontHeight <= 32){
        return 32;
    } else if (fontHeight >= 32 && fontHeight <= 64){
        return 40;
    } else if (fontHeight >= 64 && fontHeight <= 128){
        return 70;
    } else if (fontHeight >= 64 && fontHeight > 128){
        return 130;
    }
}

Result image