With the rapid emergence of various generative models, generated images have increasingly become a prominent data medium on social platforms, making up a significantly higher proportion and providing fertile ground for steganography. However, research on steganography for generated images remains limited, and the distinctive attributes, especially the reproducibility of text-to-image (TTI) models, have not been effectively leveraged. In this paper, we propose GIANT (Generated Image Adversarial steganography based on Narrowed Targeting), a novel adversarial steganography framework for generated images that employs narrowed targeting to focus on embedding the secret message solely in the secure region and synchronizing the position to enhance the steganography security. GIANT achieves narrowed targeting by leveraging the reproducibility of TTI models and fusing two regions: (1) the minimal distortion region, which is localized by measuring steganographic distortion to evaluate the impact of modifications on the cover image distribution, and (2) the critical attention region, which is localized by using coarse-grained and fine-grained attention maps to evade steganalysis detection. Additionally, for positional synchronization of the secure region, the related prompts are transmitted alongside the stego image, allowing the receiver to reconstruct the cover image using a shared key and the provided prompt. Experimental results demonstrate that GIANT significantly improves security compared to conventional and adversarial steganographic methods designed for natural images, effectively countering state-of-the-art steganalyzers.

Modeling and rendering dynamic urban driving scenes is crucial for self-driving simulation. Current high-quality methods typically rely on costly manual object tracklet annotations, while self-supervised approaches fail to capture dynamic object motions accurately and decompose scenes properly, resulting in rendering artifacts. We introduce AD-GS, a novel self-supervised framework for high-quality free-viewpoint rendering of driving scenes from a single log. At its core is a novel learnable motion model that integrates locality-aware B-spline curves with global-aware trigonometric functions, enabling flexible yet precise dynamic object modeling. Rather than requiring comprehensive semantic labeling, AD-GS automatically segments scenes into objects and background with the simplified pseudo 2D segmentation, representing objects using dynamic Gaussians and bidirectional temporal visibility masks. Further, our model incorporates visibility reasoning and physically rigid regularization to enhance robustness. Extensive evaluations demonstrate that our annotation-free model significantly outperforms current state-of-the-art annotation-free methods and is competitive with annotation-dependent approaches.

Recently, Gaussian splatting has received more and more attention in the field of static scene rendering. Due to the low computational overhead and inherent flexibility of explicit representations, plane-based explicit methods are popular ways to predict deformations for Gaussian-based dynamic scene rendering models. However, plane-based methods rely on the inappropriate low-rank assumption and excessively decompose the space-time 4D encoding, resulting in overmuch feature overlap and unsatisfactory rendering quality. To tackle these problems, we propose Grid4D, a dynamic scene rendering model based on Gaussian splatting and employing a novel explicit encoding method for the 4D input through the hash encoding. Different from plane-based explicit representations, we decompose the 4D encoding into one spatial and three temporal 3D hash encodings without the low-rank assumption. Additionally, we design a novel attention module that generates the attention scores in a directional range to aggregate the spatial and temporal features. The directional attention enables Grid4D to more accurately fit the diverse deformations across distinct scene components based on the spatial encoded features. Moreover, to mitigate the inherent lack of smoothness in explicit representation methods, we introduce a smooth regularization term that keeps our model from the chaos of deformation prediction. Our experiments demonstrate that Grid4D significantly outperforms the state-of-the-art models in visual quality and rendering speed.

Image steganography is a technique to conceal secret messages within digital images. Steganalysis, on the contrary, aims to detect the presence of secret messages within images. Recently, deep-learning-based steganalysis methods have achieved excellent detection performance. As a countermeasure, adversarial steganography has garnered considerable attention due to its ability to effectively deceive deep-learning-based steganalysis. However, steganalysts often employ unknown steganalytic models for detection. Therefore, the ability of adversarial steganography to deceive non-target steganalytic models, known as transferability, becomes especially important. Nevertheless, existing adversarial steganographic methods do not consider how to enhance transferability. To address this issue, we propose a novel adversarial steganographic scheme named Natias. Specifically, we first attribute the output of a steganalytic model to each neuron in the target middle layer to identify critical features. Next, we corrupt these critical features that may be adopted by diverse steganalytic models. Consequently, it can promote the transferability of adversarial steganography. Our proposed method can be seamlessly integrated with existing adversarial steganography frameworks. Thorough experimental analyses affirm that our proposed technique possesses improved transferability when contrasted with former approaches, and it attains heightened security in retraining scenarios.

Image steganography is the technique of concealing secret messages into digital images without arousing suspicion from detectors. Recently, adversarial steganography has received much attention from the research community, since it is effective in deceiving target deep-learning-based steganalysis (DLS) and designing more secure embedding distortion. However, how to combine adversarial steganography with handcrafted adjustment strategies to design adversarial steganography based on joint distortion has not been discussed yet. In this paper, incorporating adversarial steganography and joint distortion assignment, we present a novel adversarial steganographic scheme named JAS (Joint Adversarial Steganography). We compute joint distortion and adjust it based on joint gradient, which is a vector consisting of the gradients of two adjacent pixels, until the resulting stego image could deceive the target DLS. Furthermore, by combining JAS with synchronizing modification directions profile, we enhance the steganography security more desirably. Experiments demonstrate that the proposed method effectively enhances the anti-detection ability of joint distortion steganography.