Truefy

<a href="https://embed.truefy.ai/" rel="nofollow ugc">Truefy Embed</a> allows you to invisibly watermark images uploaded to the WordPress Media Library or a WordPress Post. 
The Plugin will also directly sync the changes in Image Caption from WordPress to Truefy Embed 
Once uploaded, you can view them in the Image library in Truefy Embed Website, where you can add or edit the critical details like Image Capture Datetime, Publisher Details etc.
For more information, check out <a href="https://embed.truefy.ai/integrations/wordpress" rel="nofollow ugc">plugin page</a> or email us at support@truefy.ai
You can check Truefy Embed’s Terms of Service at <a href="https://embed.truefy.ai/legal/tos" rel="nofollow ugc">ToS Page</a>
<h4>Features include:</h4>
<ul>
<li>Auto Invisible Watermarking – Images uploaded to Media Library or a Post can be automatically invisibly watermarked</li>
<li>Manual Invisible Watermarking/De-Watermarking – Images can be manually watermarked, and even be de-watermarked</li>
<li>Image Caption Syncing – Captions added for Images in Media Library or Post Caption, are directly synced to Truefy Embed Servers</li>
</ul>

Truefy Embed

Truefy Embed's proprietary AI invisible watermarking technology secures your images by allowing you to add critical details directly into the pix …

MyWebsiteAdvisor

ChrisHurst

This plugin allows you to Automatically add a watermark to all images as they are uploaded to the WordPress Media Library. 
The plugin uses PNG watermark images with transparency for precise control over the appearance of the watermarks. 
This plugin also supports simple text watermarks with adjustable color, size and transparency. 
The user friendly settings page allows for control over the appearance of your watermark. 
The watermark preview feature allows for easy testing of the plugin settings. 
The watermark size is controlled as a percentage of the target image, 50% means the watermark will be half the width of the target image. 
Watermarks are now removable with the new backup system, any images watermarked while the new backup system is enabled are able to be restored to the original image.
<a href="http://MyWebsiteAdvisor.com/plugins/transparent-image-watermark/" rel="nofollow ugc">Upgrade to Transparent Watermark Ultra</a> for advanced 
watermark features including:
<ul>
<li>Manually Apply Watermarks to Images Previously Uploaded</li>
<li>Fully Adjustable Image Watermark Position</li>
<li>Fully Adjustable Text Watermark Position</li>
<li>Adjustable JPEG Image Output Quality</li>
<li>Highest Quality Watermarks using Image Re-sampling rather than Re-sizing</li>
<li>Lifetime Priority Support and Update License</li>
</ul>
Check out the <a href="http://www.youtube.com/watch?v=fEhZK1U8W94" rel="nofollow ugc">Transparent Image Watermark for WordPress video</a>:
<iframe loading="lazy" title="Transparent Watermark Free Plugin for WordPress by MyWebsiteAdvisor" width="750" height="563" src="https://www.youtube.com/embed/fEhZK1U8W94?feature=oembed" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
Developer Website: http://MyWebsiteAdvisor.com/
Plugin Support: http://MyWebsiteAdvisor.com/support/
Plugin Page: http://MyWebsiteAdvisor.com/plugins/transparent-image-watermark/
Compare Watermark Plugins: http://MyWebsiteAdvisor.com/tools/wordpress-plugins/watermark-plugins-for-wordpress/
Video Tutorial: http://mywebsiteadvisor.com/learning/video-tutorials/transparent-image-watermark-tutorial/
Requirements:
<ul>
<li>PHP v5.0+</li>
<li>WordPress v3.3+</li>
<li>GD extension for PHP</li>
<li>FreeType extension for PHP</li>
</ul>
To-do:

Transparent Image Watermark

Automatically watermark images as they are uploaded to the WordPress Media Library.

Truefy Embed vs Transparent Image Watermark