obraz JavaScript to Blob
// take any image
let img = document.querySelector('img');
// make <canvas> of the same size
let canvas = document.createElement('canvas');
canvas.width = img.clientWidth;
canvas.height = img.clientHeight;
let context = canvas.getContext('2d');
// copy image to it (this method allows to cut image)
context.drawImage(img, 0, 0);
// we can context.rotate(), and do many other things on canvas
// toBlob is async operation, callback is called when done
canvas.toBlob(function(blob) {
// blob ready, download it
let link = document.createElement('a');
link.download = 'example.png';
link.href = URL.createObjectURL(blob);
link.click();
// delete the internal blob reference, to let the browser clear memory from it
URL.revokeObjectURL(link.href);
}, 'image/png');
Hungry Hare
