Canvas2D: Multiple readback operations using getImageData are faster with the willReadFrequently attribute set to true. See: <URL>

Canvas2D中，如果需要多次使用getImageData进行读取操作，可以通过设置willReadFrequently属性为true来提高读取速度。具体使用方法可以参考以下代码示例：

const canvas = document.getElementById('myCanvas');
const ctx = canvas.getContext('2d');

// 设置willReadFrequently属性为true
ctx.canvas.getContext('2d', { willReadFrequently: true });

// 多次使用getImageData进行读取操作
const imageData1 = ctx.getImageData(0, 0, 100, 100);
const imageData2 = ctx.getImageData(100, 100, 100, 100);
const imageData3 = ctx.getImageData(200, 200, 100, 100);