噪点和斑点

旧扫描和低照度拍照会有一层细麻点。墨点、灰尘则是较大的孤立黑点。体验页把它们分成「降噪」和「去斑点」。

怎么选

整页都有细颗粒、字的边缘发毛：先「降噪」。白底上散落清晰的小黑点：用「去斑点」。底色又黄又花时，先看发黄和脏背景。降噪不会把黄底变白。

在体验页怎么试

在去污体验里选一个功能运行。降噪后如果笔画变糊、小数点和标点消失，就不要用这张结果。去斑点后如果句号、顿号或图表里的小点被当成污点去掉，同样放弃这张结果。

和一键去污的关系

一键去污会串起好几步，其中可能包含类似降噪的处理。你只想去掉麻点、不想改底色时，单独跑降噪或去斑点，比一键去污更好核对。

Noise and speckles

Old scans and dim phone photos pick up a layer of fine grain. Ink spots and dust are larger, isolated black dots. The demo splits these into Denoise and Despeckle.

Which tool

Grain across the page and furry letter edges: start with Denoise. Clear small black dots on a white background: use Despeckle. If the page is also yellow and blotchy, read yellowing and dirty backgrounds first. Denoise will not turn a yellow background white.

How to try it

On the cleanup demo, run one tool. If denoise makes strokes blurry or drops decimal points and punctuation, do not keep that result. If despeckle removes periods, enumeration commas, or small marks in a chart, discard that result too.

How this relates to one-click

One-click runs several steps, which can include something like denoise. If you only want the grain gone and do not want the background changed, run denoise or despeckle alone. It is easier to check than one-click.