tf.browser.fromPixels() 不工作因为 "DOM is not ready yet"

Question

我正在尝试使用 TensorFlow.js 的 tf.browser.fromPixels() 函数。不幸的是，我收到以下错误：

backend_webgl.ts:309 Uncaught Error: The DOM is not ready yet. Please call tf.browser.fromPixels() once the DOM is ready. One way to do that is to add an event listener for `DOMContentLoaded` on the document object
    at e.fromPixels (backend_webgl.ts:309)
    at t.fromPixels (engine.ts:870)
    at fromPixels_ (browser.ts:55)
    at Object.fromPixels (operation.ts:45)
    at ex4.html:10

但我是从传递给 window.addEventListener('DOMContentLoaded', ...) 的函数内部调用 tf.browser.fromPixels()。知道为什么我会收到此错误以及如何让 fromPixels 函数工作吗？

<html>
<head>
    <script src="https://cdn.jsdelivr.net/npm/@tensorflow/tfjs@1.2.7/dist/tf.min.js"></script>
</head>
<body>
    <img id="test" src="https://jpeg.org/images/jpeg-home.jpg">
    <script>
        window.addEventListener('DOMContentLoaded', ev => {
            const img = document.getElementById('test')
            tf.browser.fromPixels(img).print()
        })
    </script>
</body>
</html>

Answer 1

        if (document.readyState !== 'complete') {
          throw new Error(
              'The DOM is not ready yet. Please call ' +
              'tf.browser.fromPixels() once the DOM is ready. One way to ' +
              'do that is to add an event listener for `DOMContentLoaded` ' +
              'on the document object');
        }

Github tensorflow/tfjs

根据上面的代码，抛出错误是因为 document.readyState 不是 complete.

The DOMContentLoaded event fires when the initial HTML document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading. https://developer.mozilla.org/en-US/docs/Web/API/Window/DOMContentLoaded_event

The readyState of a document can be one of following:

loading
The document is still loading.

interactive
The document has finished loading and the document has been parsed but sub-resources such as images, stylesheets and frames are still loading.

complete
The document and all sub-resources have finished loading. The state indicates that the load event is about to fire.
https://developer.mozilla.org/en-US/docs/Web/API/Document/readyState

DOMContentLoaded 在未加载任何子资源之前调用 yet.So 在执行代码时，document.readyState 仍然是 interactive。

忽略错误提示并尝试 load 事件侦听器。

tf.browser.fromPixels() 不工作因为 "DOM is not ready yet"

tf.browser.fromPixels() not working because "DOM is not ready yet"

javascript

tensorflow

dom-events

tensorflow.js

domcontentloaded