1. subtle
The visibility of different watermarks varies greatly. Some watermarks need to know some methods to make them appear, while others are easy to observe. Various simple methods that can produce watermark effects are gradually developed. For example, the watermark solution can even display the watermark effect without destroying the paper. ?
Watermark-free pictures are not covered by marks and external words, and the visual effect is better than that of traditional pictures.
2. Proveability
Most watermarked pictures are printed with their own unique marks. Add some digital information to realize the authenticity identification of documents, and the watermark should be reliable evidence of information products protected by copyright. Watermark can be used to judge whether the object is protected or not, and can monitor the copyright protection functions such as the dissemination of protected data, authenticity identification and illegal copy control. Watermarking usually plays a role in verifying the authenticity of currency, passports, stamps, government documents or other paper documents.
Watermark-free pictures are easy to be stolen and can be used, modified and spread.
3. Different purposes
Watermark pictures are generally advertising and commercial, and a few are mainly intellectual property rights. Watermark-free pictures have few commercial purposes and can be widely spread and used.
References:
Baidu encyclopedia-watermark