Reversible watermarking techniques and their effectiveness in combating over-the-top piracy

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Because of the rise in the demand for digital video content, it has become necessary to implement security measures such as watermarking to ensure that users’ content is not copied. Therefore, digital watermarking solutions have become a necessity for securing DRM protected content.

Watermarking is a technique that encrypts a digital file with an invisible code. Afterward, this data can be used to identify the source of leakage in the event of an infringement. The watermarked version of the content differs significantly from the original unwatermarked version, despite the fact that this small modification to the digital content is generally irreversible. Irreversible watermarking is undesirable for sensitive applications such as military investigation, medical diagnostics, space exploration, etc., because the content would be used on a slightly corrupted version.

To get around this, watermarking methods that can be reversed (also known as invertible or lossless) can be used. Both the embedded data and its restoration are possible thanks to these tools. Reversible video watermarking techniques can be broken down into three categories: robust, fragile, and semi-fragile. As a general rule, watermarks in robust schemes are able to withstand normal image frame processing operations, while those in fragile techniques disappear upon any modification of the watermarked content, thus revealing that the content has been compromised. The watermark can withstand minor unintentional changes in semi-fragile schemes.

Several new reversible watermarking approaches for DRM-protected content on OTT platforms have been outlined below:

Using compression-based revedrmrsible watermarking requires more storage space because the information needed to restore the original image is included in the data that is compressed. As a result, data embedding necessitates compressing a portion of the cover image.

Reversible watermarking methods based on the quantization technique are generally fragile. An object’s original data is encoded using a quantization scheme, the most common of which is the Quantization Index Modulation (QIMM). It is then necessary to compute and save the modulation information.

An expansion-based reversible watermarking technique that uses the pixel-based DE (difference expansion) technique and provides a high embedding capacity with low computational complexity is called expansion-based reversibility.

A robust watermarking method, histogram-based reversible watermarking uses the histogram bin as the embedding target. Because the embedding techniques are block-based, they can withstand some operations.

In order to track down the source of premium video piracy, video frames can be subjected to any or all of these techniques, depending on the use case. One of these forensic watermarking techniques, coupled with the use of a multi-DRM SaaS-based model, can help copyright holders in the OTT space to protect their intellectual property.