批注与高亮
高亮、下划线、评论和绘制——作为真正的批注，而非墨迹。
这款工具完全在你的浏览器中运行。文件从不上传，你可以在浏览器的网络标签中亲自验证这一点。 亲自验证：打开浏览器的网络标签观察。你会看到一个查询你是否还有剩余任务的小请求，只包含工具名称和一段哈希，绝不会包含文件。
这款工具的作用
The marks this tool adds are annotations, not drawings. A real highlight appears in a reader's comment list, carries your name, can be replied to, filtered and deleted; a yellow rectangle painted onto the page is ink for ever. Text markup snaps to the words underneath rather than to a rectangle you drew approximately over them.
Use it when a document is going back to whoever wrote it: marking the clause you disagree with, striking a sentence that should go, leaving a note beside a figure that looks wrong, or circling the part of a drawing that needs redoing.
工作原理
- Drop the PDF onto this page and wait for it to render.
- Select words to highlight, underline, strike out or squiggly-underline them, or pick a shape, a note or the pen for freehand ink.
- Set the colour and opacity, and type the comment that goes with the mark if it needs one.
- Put your name in Author so the recipient's comment panel says who wrote what.
- Leave Turn the comments into ink off unless the marks must not be editable.
- Press Annotate and the download starts.
Text markup follows the text. The page's text runs are read first, so a sentence that wraps over two lines becomes one annotation with a quadrilateral for each line, not one wide box slanting across the paragraph. Those quadrilaterals are written in the order the specification asks for - upper-left, upper-right, lower-left, lower-right, which is neither clockwise nor anticlockwise - and getting it wrong is why highlights from some tools render as bow-ties in Acrobat.
Nine kinds of mark are available: highlight, underline, strikeout, squiggly underline, sticky note, square, circle, line and freehand ink. All are written with the print flag set, because a review comment that vanishes when the recipient prints the document is a comment they never read. Highlights default to 40 percent opacity so the words under them stay legible.
No appearance stream is written for these annotations, so each reader draws them from the annotation data using its own conventions: a highlight looks like an Acrobat highlight in Acrobat and like a Preview highlight in Preview, and the exact edge and shade differ slightly. In exchange, the marks stay editable data rather than becoming pixels.
Turning the comments into ink runs the same pass as Flatten PDF: each annotation's appearance stream is drawn onto the page and the annotation deleted. Only marks that carry such a stream can be drawn, and ones the reader synthesises do not, so flattening immediately after adding leaves them in place. Open the file once in a reader and save it - that writes the appearances - then flatten.
Nothing about the document is sent anywhere: the name you put in Author is written into the file you download and nowhere else.
这款工具做不到的事
- Highlight, underline, strikeout and squiggly need a text layer to snap to. A scanned page has none, so run OCR PDF over it first, or mark it up with the shape and ink tools instead.
- The annotations carry no appearance stream, so each reader draws them itself and they can look slightly different between Acrobat, Preview and Chrome. Flattening cannot burn in a mark that the reader is drawing.
常见问题
- 这些是真正的 PDF 评论，还是只是画在页面上的图形？
- 是真正的批注对象。它们出现在 Acrobat、预览、Foxit 和大多数其他阅读器的批注面板中，带有作者姓名和评论文本，收到它们的人可以回复、筛选或删除。绘制的标记——也就是编辑 PDF 生成的——是页面的一部分，无法移除。
- 为什么我的高亮正好盖住文字，而不是我拖出的框？
- 因为在写入标记之前会先读取页面的文本行，所以高亮是根据你所选文字的实际位置构建的。跨三行的句子会在一个批注中变成三个四边形，这就是它能正确换行、而不是盖住每行末尾空白的原因。
- 把评论转成墨迹会做什么？
- 它把每个批注绘制到页面上并删除该批注，这样下游任何人都无法移动或移除这些标记。只有带有自身外观流的批注才能被绘制，而这里添加的标记是由阅读器渲染的——所以先在 PDF 阅读器中打开并保存一次文件（这会写入外观），再运行展平 PDF。
- 收件人会看到我的评论吗？
- 在任何支持批注的阅读器中都会，实际上几乎所有阅读器都支持，包括浏览器查看器。这些标记被设为可打印，因此在纸上也会显示。完全忽略批注的查看器会显示未标注的页面，这也是当标记必须显眼时应展平的原因。
- 文档会离开我的设备吗？
- 不会。它在你的浏览器中渲染和重写，添加到文件里的只有你输入的内容：标记、它们的评论和你选择的作者姓名。不上传任何内容，断网时这款工具仍能使用。