Base64 image resizer nodejs - node.js

Question

I am working on a node+express backend.
I am receiving base64 images string from API and I am storing it into MongoDB. Before storing I want to reduce the image size (scaling). I tried JIMP but it is not reading base64 input.
Can anyone please suggest any good node module which accepts base64 image, scale it and return a new base64 string.
Thanks

Answer 1

A little late but I just implemented this feature using the sharp library, so might as well share it now.
I created a function that takes a base64 and the height and width (optional) you want to resize the image to and returns the resized base64 string.
I can just call this function whenever I want.
Code
// Don't forget to import sharp
import sharp from "sharp"
export const resizeBase64 = async ({ base64Image, maxHeight = 640, maxWidth = 640 }) => {
const destructImage = base64Image.split(";");
const mimType = destructImage[0].split(":")[1];
const imageData = destructImage[1].split(",")[1];
try {
let resizedImage = Buffer.from(imageData, "base64")
resizedImage = await sharp(resizedImage).resize(maxHeight, maxWidth).toBuffer()
return `data:${mimType};base64,${resizedImage.toString("base64")}`
} catch (error) {
throwError({ error })
}
};

Answer 2

You can still use JIMP, but all you need to do is to drop the prefix before reading the base64.
Depend on your image format use a specific jpg or png in the following example.
Example:
Jimp.read(Buffer.from((yourImageBuffer).replace(/^data:image\/png;base64,/, ""), 'base64'), function (err, image) {
// Do you stuff here with the image
})

Answer 3

....some logic....
let max_width = 371;
let max_height = 280;
var image = new Image();
image.src = YOUR_BASE64_STRING;
let image_width = image.width;
let image_height = image.height;
let ratio = 1;
if(image_width > max_length || image_height > max_length){ //need to scale
ratio = max_length / image_width;
if(image_height > image_width){
ratio = max_length / image_height;
}
}
var canvas = document.createElement("canvas");
var ctx = canvas.getContext("2d");
canvas.width = image_width * ratio; // target width
canvas.height = image_height * ratio; // target height
ctx.drawImage(image,
0, 0, image.width, image.height,
0, 0, canvas.width, canvas.height
);
var RESIZED_BASE64_STRING = canvas.toDataURL();
....some logic....