Watermarking vs Steganography
Watermarking and steganography are processes in which the digital image is changed in a way that one can see the background image or the text without any kind of corruption in the image.
Watermarking
Watermarking is used to verify the identity and authenticity of the owner of a digital image. It is a process in which the information which verifies the owner is embedded into the digital image or signal. These signals could be either videos or pictures or audios. For example, famous artists watermark their pictures and images. If somebody tries to copy the image, the watermark is copied along with the image.
Watermarking is of two types; visible watermarking and invisible watermarking.
Visible Watermarking
As the name suggests, visible watermarking refers to the information visible on the image or video or picture. Visible watermarks are typically logos or text. For example, in a TV broadcast, the logo of the broadcaster is visible at the right side of the screen.
Invisible Watermarking
Invisible watermarking refers to adding information in a video or picture or audio as digital data. It is not visible or perceivable, but it can be detected by different means. It may also be a form or type of steganography and is used for widespread use. It can be retrieved easily.
Applications:
- It is used for copyright protection.
- It is used for source tracing.
- Annotation of photographs.
Steganography
Steganography is changing the image in a way that only the sender and the intended recipient is able to detect the message sent through it. It is invisible, and thus the detection is not easy. It is a better way of sending secret messages than encoded messages or cryptography as it does not attract attention to itself.
There are many ways in which steganography is done. The messages appear as articles, images, lists, or sometimes invisible ink is used to write between the lines. Steganography is achieved by concealing the information in computer files. Sometimes steganographic codes are inside the transport layer like an image file, document file, media files, etc. Due to the large size of the media files, they are considered ideal for steganography.
Applications
- Steganography is used in modern printers.
- It has been used allegedly by terrorists.
- It is allegedly used by intelligence services.
Summary:
- Watermarking is a process in which the information which verifies the owner is embedded into the digital image or signal. These signals could be either videos or pictures or audios; steganography is changing the image in a way that only the sender and the intended recipient are able to detect the message sent through it.
- Watermarking is of two types; visible watermarking and invisible watermarking. Steganography is typically invisible.