Rotate base64 image (Javascript)

rotate.js

function rotate(srcBase64, degrees, callback) {
  const canvas = document.createElement('canvas');
  const ctx    = canvas.getContext('2d');
  const image  = new Image();

  image.onload = function () {
    canvas.width  = degrees % 180 === 0 ? image.width : image.height;
    canvas.height = degrees % 180 === 0 ? image.height : image.width;

    ctx.translate(canvas.width / 2, canvas.height / 2);
    ctx.rotate(degrees * Math.PI / 180);
    ctx.drawImage(image, image.width / -2, image.height / -2);

    callback(canvas.toDataURL());
  };

  image.src = srcBase64;
}

// Usage:
const img = document.getElementById('image');

rotate(img.attributes.src.value, 90, function(resultBase64) {
  img.setAttribute('src', resultBase64);
});

thanks

nice! It solved my problem.

Here's an async version of this function that uses HTMLImageElement.decode()

From the docs:

This can be used to initiate loading of the image prior to attaching it to an element in the DOM (or adding it to the DOM as a new element), so that the image can be rendered immediately upon being added to the DOM. This, in turn, prevents the rendering of the next frame after adding the image to the DOM from causing a delay while the image loads.

Thank you!
I just needed these 2 lines:
canvas.width = degrees % 180 === 0 ? image.width : image.height;
canvas.height = degrees % 180 === 0 ? image.height : image.width;

thank you.

Thank you for this 👍