uni-app renderjs里面调用context.getImageData()方法报错，无法向下执行语句

uni-app renderjs里面调用context.getImageData()方法报错，无法向下执行语句

操作步骤：

在renderjs里面调用getImageData抛出了异常(模拟器正常运行，真机上面就报错了)

预期结果：

获取到canvas的imageData

实际结果：

抛出了异常

bug描述：

<script module="canvas" lang="renderjs">  
  export default {  
    data() {  
      return {  
        ctx: null  
      }  
    },  
    methods: {  
      initCanvas(newVal, oldVal, owner, ins) {  
        let canvasEle = document.querySelectorAll('.canvas>canvas')[0]  
        let imageEle = document.querySelectorAll('.image>img')[0]  
        this.ctx = canvasEle.getContext('2d')  
        this.ctx.drawImage(imageEle, 0, 0)  
        let data = this.ctx.getImageData(0, 0, canvasWidth, canvasHeight)  
        console.log(data, 'imageData')  
      }  
    }  
  }  
</script>