<canvas id ="my-canvas" width="2350px" height="1500px">
</canvas>

let myCanvas = document.getElementById('my-canvas');

let ctx = myCanvas.getContext('2d');

let pinkRoses = new Image();

pinkRoses.src = 'https://cdn.pixabay.com/photo/2017/03/31/15/32/roses-2191636_1280.jpg';

let ptrn = ctx.createPattern(pinkRoses, 'repeat');


ctx.fillStyle = ptrn;

ctx.fillRect(0, 0,1500, 2350);
ctx.fill();