Perceptual hashing method for video content authentication with maximized robustness

Perceptual video hashing represents video perceptual content by compact hash. The binary hash is sensitive to content distortion manipulations, but robust to perceptual content preserving operations. Currently, boundary between sensitivity and robustness is often ambiguous and it is decided by an empirically defined threshold. This may result in large false positive rates when received video is to be judged similar or dissimilar in some circumstances, e.g., video content authentication. In this paper, we propose a novel perceptual hashing method for video content authentication based on maximized robustness. The developed idea of maximized robustness means that robustness is maximized on condition that security requirement of hash is first met. We formulate the video hashing as a constrained optimization problem, in which coefficients of features offset and robustness are to be learned. Then we adopt a stochastic optimization method to solve the optimization. Experimental results show that the proposed hashing is quite suitable for video content authentication in terms of security and robustness.

Unpaired Remote Sensing Image Super-Resolution with Multi-Stage Aggregation Networks

Mainstream image super-resolution (SR) methods are generally based on paired training samples. As the high-resolution (HR) remote sensing images are difficult to collect with a limited imaging device, most of the existing remote sensing super-resolution methods try to down-sample the collected original images to generate an auxiliary low-resolution (LR) image and form a paired pseudo HR-LR dataset for training. However, the distribution of the generated LR images is generally inconsistent with the real images due to the limitation of remote sensing imaging devices. In this paper, we propose a perceptually unpaired super-resolution method by constructing a multi-stage aggregation network (MSAN). The optimization of the network depends on consistency losses. In particular, the first phase is to preserve the contents of the super-resolved results, by constraining the content consistency between the down-scaled SR results and the low-quality low-resolution inputs. The second stage minimizes perceptual feature loss between the current result and LR input to constrain perceptual-content consistency. The final phase employs the generative adversarial network (GAN) to adding photo-realistic textures by constraining perceptual-distribution consistency. Numerous experiments on synthetic remote sensing datasets and real remote sensing images show that our method obtains more plausible results than other SR methods quantitatively and qualitatively. The PSNR of our network is 0.06dB higher than the SOTA method—HAN on the UC Merced test set with complex degradation.

Efficient prestimulus network integration of FFA biases face perception during binocular rivalry

Ongoing fluctuations in neural excitability and connectivity influence whether or not a stimulus is seen. Do they also influence which stimulus is seen? We recorded magnetoencepahlography data while participants viewed face or house stimuli, either one at a time or under bi-stable conditions induced through binocular rivalry. Multivariate pattern analysis revealed common neural substrates for rivalrous vs. non-rivalrous stimuli with an additional delay of ~36ms for the bi-stable stimulus and post-stimulus signals were source-localized to the fusiform face area (FFA). Prior to stimulus onset followed by a face- vs. house-report, FFA showed stronger connectivity to primary visual cortex and to the rest of the cortex in the alpha frequency range (8-13 Hz) but there were no differences in local oscillatory alpha power. The pre-stimulus connectivity metrics predicted the accuracy of post-stimulus decoding and the delay associated with rivalry disambiguation suggesting that perceptual content is shaped by ongoing neural network states.

Nonconceptualism and content independence

State Nonconceptualism is the view that perceptual states (not perceptual content) are different in kind from cognitive states (not cognitive content), insofar as a subject could be in perceptual states even if she lacked the concepts necessary to describe those states. Although this position has recently met serious criticism, this piece aims to argue on its behalf. A point I specifically want to highlight is that, thanks to State Nonconceptualism, it is possible to characterize perceptual experiences as nonconceptual or concept-independent without relying on the notion of perceptual content - a feature I term here the content independence of State Nonconceptualism. I think one should welcome this result: for, although a nonconceptualist characterization of perceptual experience is quite plausible, nonrepresentationalist approaches to perception have persuasively challenged the thought that perceptual experiences have representational content. This brief piece is divided into three parts: (i) I introduce two versions of Perceptual Nonconceptualism, namely, Content and State Nonconceptualism; (ii) I go on to stress State Nonconceptualism’s content independence; and (iii), I briefly address three prominent objections against the state nonconceptualist.

Depicting Properties’ Properties

Little has been said about whether pictures can depict properties of properties. This article argues that they do. As a result, resemblance theories of depiction must be changed to accommodate this phenomenon. In addition, diagrams and maps are standardly understood to represent properties of properties, so this article brings accounts of depiction closer to accounts of diagrams than they had been before. Finally, the article suggests that recent work on perceptual content gives us reason to believe we can perceive properties of properties.

Evidence for a visual bias when recalling complex narratives

Although it is understood that episodic memories of everyday events involve encoding a wide array of perceptual and non-perceptual information, it is unclear how these distinct types of information are recalled. To address this knowledge gap, we examine how perceptual (visual versus auditory) and non-perceptual details described within a narrative, a proxy for everyday event memories, were retrieved. Based on previous work indicating a bias for visual content, we hypothesized that participants would be most accurate at recalling visually described details and would tend to falsely recall non-visual details with visual descriptors. In Study 1, participants watched videos of a protagonist telling narratives of everyday events under three conditions: with visual, auditory, or audiovisual details. All narratives contained the same non-perceptual content. Participants’ free recall of these narratives under each condition were scored for the type of details recalled (perceptual, non-perceptual) and whether the detail was recalled with gist or verbatim memory. We found that participants were more accurate at gist and verbatim recall for visual perceptual details. This visual bias was also evident when we examined the errors made during recall such that participants tended to incorrectly recall details with visual information, but not with auditory information. Study 2 tested for this pattern of results when the narratives were presented in auditory only format. Results conceptually replicated Study 1 in that there was still a persistent visual bias in what was recollected from the complex narratives. Together, these findings indicate a bias for recruiting visualizable content to construct complex multi-detail memories.

Untying the knot: imagination, perception and their neural substrates

How tight is the conceptual connection between imagination and perception? A number of philosophers, from the early moderns to present-day predictive processing theorists, tie the knot as tightly as they can, claiming that states of the imagination, i.e. mental imagery, are a proper subset of perceptual experience. This paper labels such a view ‘perceptualism’ about the imagination and supplies new arguments against it. The arguments are based on high-level perceptual content and, distinctly, cognitive penetration. The paper also defuses a recent, influential argument for perceptualism based on the ‘discovery’ that visual perception and mental imagery share a significant neural substrate: circuitry in V1, the brain’s primary visual cortex. Current neuropsychology is shown to be equivocal at best on this matter. While experiments conducted on healthy, neurotypical subjects indicate substantial neural overlap, there is extensive clinical evidence of dissociations between imagery and perception in the brain, most notably in the case of aphantasia.

Presentational Conservatism

Presentational Conservatism is the view that if, and only if, you have an experience that has presentational phenomenology with respect to p, then do you thereby have some prima facie justification for believing that p. This chapter defends Presentational Conservatism and explores its epistemic implications. Once located in relation to other dogmatist and phenomenal conservative approaches to justification, the view is clarified through discussion of presentational phenomenology and motivated on the basis of reflection on cases and general epistemological considerations. If Presentational Conservatism is true, then various epistemological agendas that have been pursued in the wake of the literature on high-level perceptual content need to be reassessed. Implications for recently popular perceptual accounts of our knowledge of other minds are explored in some detail.

Psycho-Semantics of Perceptual Content

A general problem faced by psychology is that of accounting for an organism’s sensitivities to non-local, non-physical, and/or non-instantiated—what I call “abstruse”—properties, such as, e.g., being a dinosaur, being a triangle, or being a noun or a sentence. I argue that only an intentionalistically understood CRT (an “II-CRT”) offers the best prospect of explaining these sensitivities, which it does by a mutually supporting combination of the BasicAsymmetry proposal of §10.3 and of the kind of probability theories routinely presupposed by theories of perception. I will then briefly discuss various sources of resistance to intentionalism and how they motivate the methodological dualism that Chomsky deplores, despite his sharing many of those motivations and the dualism himself. I will conclude the book with some comments on the “mind/body” problem(s) that, pace Chomsky’s recent writings, are as alive and interesting as ever.