On the steganographic image based approach to PDF files protection

TL;DR

This paper explores image-based steganography techniques for protecting PDF files, comparing spatial and frequency domain watermarking methods, and finds spatial LSB embedding more effective than frequency-based DWT.

Contribution

It introduces and evaluates two watermarking schemes for PDF images, highlighting the advantages of spatial domain LSB over frequency domain embedding.

Findings

Spatial LSB watermarking is more preferable than frequency DWT embedding.

Both schemes successfully extract and embed watermarks in PDF images.

The methods enable visible and invisible watermarking for PDF protection.

Abstract

Digital images can be copied without authorization and have to be protected. Two schemes for watermarking images in PDF document were considered. Both schemes include a converter to extract images from PDF pages and return the protected images back. Frequency and spatial domain embedding were used for hiding a message presented by a binary pattern. We considered visible and invisible watermarking and found that spatial domain LSB technique can be more preferable than frequency embedding using DWT.