Since a digital copy of data is the same as the original, digital watermarking is a passive protection tool. A watermark is embedded into a digital signal at each point of distribution. If a copy of the work is found later, then the watermark may be retrieved from the copy and the source of the distribution is known.
Digital watermarking is a technology in which identification information is embedded into the data carrier in ways that cannot be easily noticed, and in which the data usage will not be affected. This technology often protects copyright of multimedia data, and protects databases and text files.
There are two types of digital watermarking , visible and invisible.
Watermarking is the process of superimposing a logo or piece of text atop a document or image file, and it’s an important process when it comes to both the copyright protection and marketing of digital works.
A watermark is a graphic that is added to an image to assert your copyright or ownership, typically by using photoshop or another online program to apply the mark. A watermark may use your company’s name, your personal name, or your logo. Again, the watermark itself is not a copyright .
A watermark is a logo, text, or pattern that is intentionally superimposed onto another image. Its purpose is to make it more difficult for the original image to be copied or used without permission.
How to Create a Watermark for Your Images Open your logo, make it white on a transparent background, and save as a PNG. Open the image you want to put a watermark on. Click Add an image, and fetch your logo from where you’ve stored it. Resize your logo and place it in a corner of your image. Use the Fade slider to adjust your logo’s transparency.
So using watermarks with protected documents offers many advantages to a publisher: as a copying deterrent. as a means of identifying the source of a printed document . as a means of determining whether a document has been altered.
In this chapter, the watermarking technique is blind ; blind watermarking does not need any of the original images or any information about it to recover watermark . In this technique the watermark is inserted into the high frequencies. Significant coefficients are used to embed the watermark .
With the rapid development of network and digital technology, security of digital contents becomes a serious problem. Digital watermarking can provide an effective security protection to digital contents.
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.
Technically originating in the art of papermaking, in photography, the watermark is a superimposed image , logo, or text placed over a photograph—usually as a method of identifying the image’s creator.
Photographers often add a watermark to their photos in order to protect their work from being used without their permission.
Traditionally, a watermark was made by impressing a water-coated metal stamp or dandy roll onto the paper during manufacturing. The invention of the dandy roll in 1826 by John Marshall revolutionised the watermark process and made it easier for producers to watermark their paper.