JS Canvas putImageData呈现的色差

Question

使用JS Canvas putImageData操纵像素时，所需颜色和渲染颜色有所不同。在绘制RGB（255,255,0）时，画布上的输出是RGB（254,254,86）。其他值也是如此。问题出在哪里？

这是 JSFiddle

选中 Screenshot

ProxyFactory factory = new ProxyFactory();
factory.setTarget(obj);
factory.setOptimize(true);
factory.setExposeProxy(true);
factory.addAdvisor(advisor);
factory.addInterface(FirstInterface.class);
factory.addInterface(SecondInterface.class);
Object proxied = pf.getProxy();