Unverified50% confidenceTradeoffExact time
The cost of text extraction is: when a page relies on Canvas rendering, dynamic charts, or purely visual states (such as a button being grayed out when disabled), text extraction loses information, and in this case one needs to fall back to screenshots.
1
Sources
50%
Confidence
Long-term
Relevance
10/15/2026
First Seen
Sources
Related Entities
Related Claims
UnverifiedWhen content is rendered on a Canvas as pixels, screen readers cannot read the Canvas content, browser auto-translation cannot act on pixels, and capabilities such as text selection, SEO, and the accessibility tree cease to function.71% similarUnverified使用 Canvas、GPU 直接渲染或自绘 UI 的应用，其屏幕内容无法通过 Accessibility API 或 DOM 解析获取，只能退回到截图加 OCR 路径，这是纯文本屏幕记忆方案最根本的覆盖盲区69% similarUnverifiedBecause Canvas content is an opaque bitmap to screen readers, editors must maintain a parallel ARIA tree or hidden DOM structure to convey document content and structure to assistive technologies.69% similarVerifiedCanvas API uses an immediate-mode rendering mechanism that clears the canvas each frame and redraws all elements, which is fundamentally different from the retained-mode approach of DOM manipulation.68% similarUnverifiedWhen rendering documents with Canvas, every character, line, and table border requires the developer to manually calculate coordinates and call drawing APIs, as Canvas does not maintain an element tree structure.68% similar
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