Digital watermarking is the process by which an image is coded(embedded) with an owner's watermark. The file could be an image, audio, video or text. Nowadays, digital watermarking has many applications such as broadcast monitoring, owner identification, proof of ownership, transaction tracking, content authentication, copy control, device control, and file reconstruction.
The main specifications of a watermarking system are: Robustness (Against intentional attacks or unintentional ones such as compression), Imperceptibility, and Capacity. Importance of each depends on the application.
Watermark can be implemented on the images with three following techniques as following:
- Watermarking in Spatial domain
- Watermarking in Frequency domain
- Watermarking in Hybrid domain
This app includes variety of options of watermarking using all the three techniques. This also provides a comparision between outputs from different techniques. Output produced is a gray scale image.