mryuanshu

WppaoImage图片增强插件，来自Wppao团队缘殊开发，只为完成网站运营时必须要的几个图片处理功能，如远程图片本地化，图片加水印等功能。
目前支持的功能： 
* 图片文字水印功能 
* 图片文字水印字体自选 
* 图片文字水印尺寸自选 
* 图片文字水印颜色自选 
* 图片使用图片水印功能 
* 水印位置自选

Wppao Image

Wordpress图片增强插件，可以将远程图片获取到本地，并且可以对文章的图片打水印。

NsThemes

Apply your watermark on your WooCommerce product images — without overwriting them!
NS Watermark For WooCommerce overlays a watermark image on top of your shop and single-product photos at display time. 
The original files stored in your Media Library are never modified.
Features (free version)
<ul>
<li>Choose any image from your Media Library as the watermark.</li>
<li>Always show the watermark, or show it only to guests (not logged-in users).</li>
<li>Enable / disable with a single setting.</li>
<li>Compatible with WordPress 7.0 and WooCommerce 10.8.1.</li>
<li>No GD extensions need to be installed separately (bundled with PHP ≥ 7.4).</li>
</ul>
3rd Party / External Services
<ul>
<li>PluginEye — used for opt-in usage tracking (plugin activation/deactivation events, site address, WordPress version, active plugin list). Data is collected only after explicit user consent is given on the opt-in screen shown at first activation. Read more: <a href="https://www.plugineye.com/privacy-policy/" rel="nofollow ugc">Privacy Policy</a> — <a href="https://www.plugineye.com/terms-of-service/" rel="nofollow ugc">Terms of Service</a>. This service is provided by NsThemes.</li>
</ul>
All watermark image processing is performed locally on your web server using PHP’s built-in GD library. No image data is sent to external servers.

NS Watermark For WooCommerce

Protect your WooCommerce product images by overlaying a watermark on-the-fly — no permanent changes to your files.

Wppao Image vs NS Watermark For WooCommerce