如何将画布图像数据复制到paper.js光栅对象中

I'm trying to add Caman.js filter functionality to a paper.js Raster. And in order not to loose image information I want to reset the image data to the original data (_camanImageData) every time before I call Caman by copying it from a cloned raster. The code is like this:I'm trying to add Caman.js filter functionality