Since you asked, I decided to expand a bit in this post.
ttyr2 Don't forget, this does nothing to keep people from actually getting the image if they want. Screen captures and apps like wget can still download it.
It's mostly the fact that all images that are viewed in a browser, must also load into the browser. That means anyone can simply open browser > developer > network, and see (and download) all images that load into browser. This is a constant that applies for all websites without exceptions. Also, there are browser plugins that can simply download all images on page.
ttyr2 Is there a way for files.gallery to overlay some sort of copyright notice on all the photos in a gallery? That could be handy.
Files app could "overlay" logo/copyright over images in the browser, but this happens after the images are loaded, so it does not really solve anything (including what I mentioned above). The BEST scenario that can be achieved without watermarking:
- Make it difficult for "average" users to download your images by blocking right-click and removing download buttons (as in this post).
- Limit your images in dimensions (suitable for screens) and JPG quality. At least nobody will be able to download print-quality original non-compressed images.
It is commonly known that the only method of protecting your uploaded images, is to apply watermarking (see wiki) before the images are uploaded, or apply the watermark on server before the images load into browser. This obviously makes the image unusable for downloading, although it also makes it less enjoyable to view. Heavy watermarking example from Shutterstock:
As noted, watermarking must happen BEFORE each image loads into browser. In other words, the uploaded images must already be watermarked, or there must be a server mechanism that dynamically watermarks images, and at the same time blocks access to the original non-watermarked images.
Watermarking from Files app
This could be an interesting feature in the future, but there are several logical challenges:
- When applying a watermark via server PHP, images will get re-compressed in JPG format (meaning there will be a tiny degrade in quality).
- The original non-watermarked images would need to get deleted somehow as soon as the watermarked version is created. Or, there would need to be some server mechanism in place that blocks public access to the original non-watermarked images.
- Server will require sufficient memory to process watermarks on large images.
- Images will need to load through PHP instead of accessed directly.
- Optionally (to all the above), it might be possible to add the watermark from the uploader, although this means the watermark will also be assigned to the small preview images, which seems unnecessary.
* Watermarking from Files app could be interesting, but there would be several logical challenges to resolve.
Watermarking before upload
This option is already available to you from several desktop applications, or from online services. Basically you would need to create watermarked copies of all your images prior to upload. Obviously not convenient, but it's an option for those who require true image download protection.
Watermark images web service: