阴影和装订处暗带

手机对着摊开的书拍照，订口常常有一条由深到浅的暗带。平板扫描仪压不平的书也一样。

和发黄的区别

发黄是整页颜色偏了。阴影是同一页里一块明显更暗，通常贴着装订线或页面一侧。整页均匀发灰不要用去阴影，请看发黄和脏背景。

在体验页怎么试

在去污体验里选「去阴影」，打开示例或上传，点运行。看暗带是否变浅，以及暗带里的字是否还在。暗带没变化、整页却更花，说明问题主要是底色或噪点，改试一键去污或降噪。

跑完要核对

订口附近的字、页码和装订侧的表格线。去阴影会抬高暗区亮度，暗区里的浅字可能和背景糊在一起。折痕很深、纸已经拱起时，暗带往往只能减轻，不能消失。

Shadows and gutter bands

A phone photo of an open book often has a dark band along the gutter that fades toward the outer edge. A book that will not lie flat on a flatbed scanner does the same.

How this differs from yellowing

Yellowing shifts the color of the whole page. A shadow is one region that is clearly darker, usually against the binding or one side. A page that is evenly gray is not a shadow. See yellowing and dirty backgrounds.

How to try it

On the cleanup demo, select Deshadow, open a sample or upload, and run. See whether the band lightened and whether the words inside it are still there. If the band is unchanged and the page looks noisier, the problem is the background or grain. Try one-click or denoise.

What to check afterward

Text near the gutter, page numbers, and rules on the binding side. Deshadow lifts the dark area, so light text there can blend into the background. A deep crease or a page that is still buckled will usually only get lighter, not flat.