Yes—what you’re describing is usually called a digital watermark; more broadly, hiding data in an image is related to steganography. A digital watermark can embed identifying information in the image data in a way that may be hard to notice or remove.

However, it is not foolproof. Editing, recompression, resizing, format conversion, and especially printing/scanning can weaken or destroy hidden data. Metadata is even easier to strip. So this is not a reliable “can’t be deleted” solution, nor something search engines will automatically detect.

For copyright protection, the stronger approach is legal and procedural: keep your originals, document your work, and register your images with the relevant government copyright authority where applicable. That gives you much stronger proof if someone misuses your photos.

A practical extra precaution is to provide only what the publisher needs—for example, a slightly reduced file or a version that omits a tiny border or other nonessential part that only your original contains. That can help distinguish your master file from copies.

So: hidden watermarking exists and may help support a claim, but it should be treated as a supplement, not your main protection.