Preferred color correction for mixed taking-illuminant placement and cropping

The growth of automatic layout capabilities for publications such as photo books and image sharing websites enables consumers to create personalized presentations without much experience or the use of professional page design software. Automated color correction of images has been well studied over the years, but the methodology for determining how to correct images has almost exclusively considered images as independent indivisible objects. In modern documents, such as photo books or web sharing sites, images are automatically placed on pages in juxtaposition to others and some images are automatically cropped. Understanding how color correction preferences are impacted by complex arrangements has become important. A small number of photographs taken under a variety illumination conditions were presented to observers both individually and in combinations. Cropped and uncropped versions of the shots were included. Users had opportunities to set preferred color balance and chroma for the images within the experiment. Analyses point toward trends indicating a preference for higher chroma for most cropped images in comparison to settings for the full spatial extent images. It is also shown that observers make different color balance choices when correcting an image in isolation versus when correcting the same image in the presence of a second shot taken under a different illuminant. Across 84 responses, approximately 60% showed the tendency to choose image white points that were further from the display white point when multiple images from different taking illuminants were simultaneously presented versus when the images were adjusted in isolation on the same display. Observers were also shown to preserve the relative white point bias of the original taking illuminants

Digital Image Access & Retrieval

The 33th Annual Clinic on Library Applications of Data Processing, held at the University of Illinois at Urbana-Champaign in March of 1996, addressed the theme of "Digital Image Access & Retrieval." The papers from this conference cover a wide range of topics concerning digital imaging technology for visual resource collections. Papers covered three general areas: (1) systems, planning, and implementation; (2) automatic and semi-automatic indexing; and (3) preservation with the bulk of the conference focusing on indexing and retrieval.published or submitted for publicatio

Colouration in amphibians as a reflection of nutritional status : the case of tree frogs in Costa Rica

Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals

Tissue-Specific Transcriptomes Reveal Gene Expression Trajectories in Two Maturing Skin Epithelial Layers in Zebrafish Embryos.

Epithelial cells are the building blocks of many organs, including skin. The vertebrate skin initially consists of two epithelial layers, the outer periderm and inner basal cell layers, which have distinct properties, functions, and fates. The embryonic periderm ultimately disappears during development, whereas basal cells proliferate to form the mature, stratified epidermis. Although much is known about mechanisms of homeostasis in mature skin, relatively little is known about the two cell types in pre-stratification skin. To define the similarities and distinctions between periderm and basal skin epithelial cells, we purified them from zebrafish at early development stages and deeply profiled their gene expression. These analyses identified groups of genes whose tissue enrichment changed at each stage, defining gene flow dynamics of maturing vertebrate epithelia. At each of 52 and 72 hr post-fertilization (hpf), more than 60% of genes enriched in skin cells were similarly expressed in both layers, indicating that they were common epithelial genes, but many others were enriched in one layer or the other. Both expected and novel genes were enriched in periderm and basal cell layers. Genes encoding extracellular matrix, junctional, cytoskeletal, and signaling proteins were prominent among those distinguishing the two epithelial cell types. In situ hybridization and BAC transgenes confirmed our expression data and provided new tools to study zebrafish skin. Collectively, these data provide a resource for studying common and distinguishing features of maturing epithelia

Gamut extension algorithm development and evaluation for the mapping of standard image content to wide-gamut displays

Wide-gamut display technology has provided an excellent opportunity to produce visually pleasing images, more so than in the past. However, through several studies, including Laird and Heynderick, 2008, it was shown that linearly mapping the standard sRGB content to the gamut boundary of a given wide-gamut display may not result in optimal results. Therefore, several algorithms were developed and evaluated for observer preference, including both linear and sigmoidal expansion algorithms, in an effort to define a single, versatile gamut expansion algorithm (GEA) that can be applied to current display technology and produce the most preferable images for observers. The outcome provided preference results from two displays, both of which resulted in large scene dependencies. However, the sigmoidal GEAs (SGEA) were competitive with the linear GEAs (LGEA), and in many cases, resulted in more pleasing reproductions. The SGEAs provide an excellent baseline, in which, with minor improvements, could be key to producing more impressive images on a wide-gamut display

Derivation and modelling hue uniformity and development of the IPT color space

Metric color spaces have been determined to be significantly non-uniform in the hue attribute of color appearance. Several independent sources have confirmed the non-uniformity. A data set was obtained during the course of this thesis work that contains the largest sampling of color space to date which can be used to compare models of color appearance. The data set obtained was compared to existing data sets and found to correspond closely. Lookup table methods were employed to test significant differences between data sets. A simple modeling approach was taken based on commonly understood color space models and knowledge of the visual system. Several color spaces can be derived using the simple model, and one was chosen that models hue uniformity very well and has other desirable attributes. This new color space is named IPT. Many visual data sets were plotted in the IPT color space and all show improved performance over industry standard color spaces. The IPT color space has applications in color data representation, gamut mapping, and color appearance modeling

A Human-Derived Monoclonal Antibody Targeting Extracellular Connexin Domain Selectively Modulates Hemichannel Function

Connexin hemichannels, which are plasma membrane hexameric channels (connexons) composed of connexin protein protomers, have been implicated in a host of physiological processes and pathological conditions. A number of single point pathological mutations impart a "leaky" character to the affected hemichannels, i.e., make them more active or hyperactive, suggesting that normal physiological condition could be recovered using selective hemichannel inhibitors. Recently, a human-derived monoclonal antibody named abEC1.1 has been shown to inhibit both wild type and hyperactive hemichannels composed of human (h) connexin 26 (hCx26) subunits. The aims of this work were (1) to characterize further the ability of abEC1.1 to selectively modulate connexin hemichannel function and (2) to assess its in vitro stability in view of future translational applications. In silico analysis of abEC1.1 interaction with the hCx26 hemichannel identified critically important extracellular domain amino acids that are conserved in connexin 30 (hCx30) and connexin 32 (hCx32). Patch clamp experiments performed in HeLa DH cells confirmed the inhibition efficiency of abEC1.1 was comparable for hCx26, hCx30 and hCx32 hemichannels. Of note, even a single amino acid difference in the putative binding region reduced drastically the inhibitory effects of the antibody on all the other tested hemichannels, namely hCx30.2/31.3, hCx30.3, hCx31, hCx31.1, hCx37, hCx43 and hCx45. Plasma membrane channels composed of pannexin 1 were not affected by abEC1.1. Finally, size exclusion chromatography assays showed the antibody does not aggregate appreciably in vitro. Altogether, these results indicate abEC1.1 is a promising tool for further translational studies

Virtual Reality simulator for dental anesthesia training in the inferior alveolar nerve block

Objectives This study shows the development and validation of a dental anesthesia-training simulator, specifically for the inferior alveolar nerve block (IANB). The system developed provides the tactile sensation of inserting a real needle in a human patient, using Virtual Reality (VR) techniques and a haptic device that can provide a perceived force feedback in the needle insertion task during the anesthesia procedure. Material and Methods To simulate a realistic anesthesia procedure, a Carpule syringe was coupled to a haptic device. The Volere method was used to elicit requirements from users in the Dentistry area; Repeated Measures Two-Way ANOVA (Analysis of Variance), Tukey post-hoc test and averages for the results’ analysis. A questionnaire-based subjective evaluation method was applied to collect information about the simulator, and 26 people participated in the experiments (12 beginners, 12 at intermediate level, and 2 experts). The questionnaire included profile, preferences (number of viewpoints, texture of the objects, and haptic device handler), as well as visual (appearance, scale, and position of objects) and haptic aspects (motion space, tactile sensation, and motion reproduction). Results The visual aspect was considered appropriate and the haptic feedback must be improved, which the users can do by calibrating the virtual tissues’ resistance. The evaluation of visual aspects was influenced by the participants’ experience, according to ANOVA test (F=15.6, p=0.0002, with