PixInWav: Residual Steganography for Hiding Pixels in Audio

TL;DR

PixInWav introduces a novel multimodal steganography method that embeds images into audio using a residual architecture on STDCT spectrograms, enabling offline encoding and independent image hiding without degrading audio quality.

Contribution

The paper presents a new residual architecture for hiding images in audio spectrograms, allowing offline image encoding and independent embedding without affecting audio quality.

Findings

Residual architecture enables independent image encoding in audio.

The method allows offline image hiding in audio signals.

Lab tests confirm effective transmission of images via audio.

Abstract

Steganography comprises the mechanics of hiding data in a host media that may be publicly available. While previous works focused on unimodal setups (e.g., hiding images in images, or hiding audio in audio), PixInWav targets the multimodal case of hiding images in audio. To this end, we propose a novel residual architecture operating on top of short-time discrete cosine transform (STDCT) audio spectrograms. Among our results, we find that the residual audio steganography setup we propose allows independent encoding of the hidden image from the host audio without compromising quality. Accordingly, while previous works require both host and hidden signals to hide a signal, PixInWav can encode images offline -- which can be later hidden, in a residual fashion, into any audio signal. Finally, we test our scheme in a lab setting to transmit images over airwaves from a loudspeaker to a microphone verifying our theoretical insights and obtaining promising results.