Optimum non linear binary image restoration through linear grey-scale operations

Non-linear image processing operators give excellent results in a number of image processing tasks such as restoration and object recognition. However they are frequently excluded from use in solutions because the system designer does not wish to introduce additional hardware or algorithms and because their design can appear to be ad hoc. In practice the median filter is often used though it is rarely optimal. This paper explains how various non-linear image processing operators may be implemented on a basic linear image processing system using only convolution and thresholding operations. The paper is aimed at image processing system developers wishing to include some non-linear processing operators without introducing additional system capabilities such as extra hardware components or software toolboxes. It may also be of benefit to the interested reader wishing to learn more about non-linear operators and alternative methods of design and implementation. The non-linear tools include various components of mathematical morphology, median and weighted median operators and various order statistic filters. As well as describing novel algorithms for implementation within a linear system the paper also explains how the optimum filter parameters may be estimated for a given image processing task. This novel approach is based on the weight monotonic property and is a direct rather than iterated method

Releasing aperture filter constraints

Aperture filters are a recently introduced class of nonlinear filters used in image processing. In this paper we present a new approach for aperture filter design, improving operator performance with respect to the MSE measure by releasing some of the operator constraints without losing statistical estimation accuracy. With the use of the proposed methods an average of 34% MSE reduction was achieved for deblurring, whereas a standard aperture operator reduced the error by only 10% on the average

Geddes at UCL “There was something more in town planning than met the eye!”

Patrick Geddes was at UCL from 1877 to 1878 although as a student of physiology, not as the ‘father of British Town Planning’ as he was to become. We explore his time here and the links he had both back to Charles Darwin and forward to Patrick Abercrombie. This is part of our wider quest to assess the impact of Geddes on evolutionary theory in the study of cities and planning of which we plan a more substantial paper which we will, in due course, post on this web site

A new design tool for feature extraction in noisy images based on grayscale hit-or-miss transforms

The Hit-or-Miss transform (HMT) is a well known morphological transform capable of identifying features in digital images. When image features contain noise, texture or some other distortion, the HMT may fail. Various researchers have extended the HMT in different ways to make it more robust to noise. The most successful, and most recent extensions of the HMT for noise robustness, use rank order operators in place of standard morphological erosions and dilations. A major issue with the proposed methods is that no technique is provided for calculating the parameters that are introduced to generalize the HMT, and, in most cases, these parameters are determined empirically. We present here, a new conceptual interpretation of the HMT which uses a percentage occupancy (PO) function to implement the erosion and dilation operators in a single pass of the image. Further, we present a novel design tool, derived from this PO function that can be used to determine the only parameter for our routine and for other generalizations of the HMT proposed in the literature. We demonstrate the power of our technique using a set of very noisy images and draw a comparison between our method and the most recent extensions of the HMT

I’m so Self-Conscious: Kanye West’s Rhetorical Wrestling with Theodicy and Nihilism

Whether Kanye’s plea to God is to intervene because “the devil’s trying to break [him] down,” or that he (Kanye) is “tryna keep [his] faith,” Kanye West’s lamentations communicate his wrestling of succumbing to sufferings within the world. Despite the twelve-year span between “Jesus Walks” and “Ultralight Beam,” Kanye West’s rhetoric in both songs attempt to make meaning of theodicy—suffering; while simultaneously combating nihilism—the lack of hope. As a professed Christian who articulates the multiplicity of God through Jesus and himself (Kanye West), affirmed on his 2013 album Yeezus track, “I am God,” West complicates religiosity and self-consciousness. He does so by situating himself as both God and human; recognizing limitations of God who has yet to impact his situation as a Black man in America, and his human-self that operates as a venerated deity. West’s consciousness is an amalgamation of his warring with theodicy and nihilism. My essay implements a theo-rhetorical analysis of “Jesus Walks” and “Ultralight Beam” exploring meaning-making processes of locating God. In doing so, I define theodicy and nihilism as repelling mores that aid in self-preservation for West

Resonating valence bond wave function for the two dimensional fractional spin liquid

The unconventional low-lying spin excitations, recently observed in neutron scattering experiments on ${\rm Cs_2 Cu Cl_4}$, are explained with a spin liquid wave function. The dispersion relation as well as the wave vector of the incommensurate spin correlations are well reproduced within a projected BCS wave function with gapless and fractionalized spin-1/2 excitations around the nodes of the BCS gap function. The proposed wave function is shown to be very accurate for one-dimensional spin-1/2 systems, and remains similarly accurate in the two-dimensional model corresponding to ${\rm Cs_2 Cu Cl_4}$, thus representing a good ansatz for describing spin fractionalization in two dimensions.Comment: 5 pages, 4 figures. To appear in Phys. Rev. Let

Chapter 9 Gene Drive Strategies for Population Replacement

Gene drive systems are selfish genetic elements capable of spreading into a population despite a fitness cost. A variety of these systems have been proposed for spreading disease-refractory genes into mosquito populations, thus reducing their ability to transmit diseases such as malaria and dengue fever to humans. Some have also been proposed for suppressing mosquito populations. We assess the alignment of these systems with design criteria for their safety and efficacy. Systems such as homing endonuclease genes, which manipulate inheritance through DNA cleavage and repair, are highly invasive and well-suited to population suppression efforts. Systems such as Medea, which use combinations of toxins and antidotes to favor their own inheritance, are highly stable and suitable for replacing mosquito populations with disease-refractory varieties. These systems offer much promise for future vector-borne disease control

The challenges of viewpoint-taking when learning a sign language: Data from the 'frog story' in British Sign Language

Little is known about how hearing adults learn sign languages. Our objective in this study was to investigate how learners of British Sign Language (BSL) produce narratives, and we focused in particular on viewpoint-taking. Twenty-three intermediate-level learners of BSL and 10 deaf native/early signers produced a narrative in BSL using the wordless picture book Frog, where are you? (Mayer, 1969). We selected specific episodes from part of the book that provided rich opportunities for shifting between different characters and taking on different viewpoints. We coded for details of story content, the frequency with which different viewpoints were used and how long those viewpoints were used for, and the numbers of articulators that were used simultaneously. We found that even though learners’ and deaf signers’ narratives did not differ in overall duration, learners’ narratives had less content. Learners used character viewpoint less frequently than deaf signers. Although learners spent just as long as deaf signers in character viewpoint, they spent longer than deaf signers in observer viewpoint. Together, these findings suggest that character viewpoint was harder than observer viewpoint for learners. Furthermore, learners were less skilled than deaf signers in using multiple articulators simultaneously. We conclude that challenges for learners of sign include taking character viewpoint when narrating a story and encoding information across multiple articulators simultaneously

Postsynthetic modification of zirconium metal-organic frameworks

Metal-organic frameworks (MOFs) have been in the spotlight for a number of years due to their chemical and topological versatility. As MOF research has progressed, highly functionalised materials have become desirable for specific applications, and in many cases the limitations of direct synthesis have been realised. This has resulted in the search for alternative synthetic routes, with postsynthetic modification (PSM), a term used to collectively describe the functionalisation of pre-synthesised MOFs whilst maintaining their desired characteristics, becoming a topic of interest. Advances in the scope of reactions performed are reported regularly; however reactions requiring harsh conditions can result in degradation of the framework. Zirconium-based MOFs present high chemical, thermal and mechanical stabilities, offering wider opportunities for the scope of reaction conditions that can be tolerated, which has seen a number of successful examples reported. This microreview discusses pertinent examples of PSM resulting in enhanced properties for specific applications, alongside fundamental transformations, which are categorised broadly into covalent modifications, surface transformations, metalations, linker and metal exchange, and cluster modifications