What image features guide lightness perception?

Lightness constancy is the ability to perceive black and white surface colors under a wide range of lighting conditions. This fundamental visual ability is not well understood, and current theories differ greatly on what image features are important for lightness perception. Here we measured classification images for human observers and four models of lightness perception to determine which image regions influenced lightness judgments. The models were a high-pass-filter model, an oriented difference-of-Gaussians model, an anchoring model, and an atmospheric-link-function model. Human and model observers viewed three variants of the argyle illusion (Adelson, 1993) and judged which of two test patches appeared lighter. Classification images showed that human lightness judgments were based on local, anisotropic stimulus regions that were bounded by regions of uniform lighting. The atmospheric-link-function and anchoring models predicted the lightness illusion perceived by human observers, but the high-pass-filter and oriented-difference-of-Gaussians models did not. Furthermore, all four models produced classification images that were qualitatively different from those of human observers, meaning that the model lightness judgments were guided by different image regions than human lightness judgments. These experiments provide a new test of models of lightness perception, and show that human observers' lightness computations can be highly local, as in low-level models, and nevertheless depend strongly on lighting boundaries, as suggested by midlevel models.York University Librarie

Towards a model of expectation-driven perception

Human perception is an active process by which meaningful information is gathered from the external environment. Application areas such as human-computer interaction (HCI), or the role of human experts in image analysis, highlight the need to understand how humans, especially experts, use prior information when interpreting what they see. Here, we describe how CHREST, a model of expert perception, is currently being extended to support expectation-driven perception of bitmap-level image data, focusing particularly on its ability to learn semantic interpretations

An adaptive perception-based image preprocessing method

The aim of this paper is to introduce an adaptive preprocessing procedure based on human perception in order to increase the performance of some standard image processing techniques. Specifically, image frequency content has been weighted by the corresponding value of the contrast sensitivity function, in agreement with the sensitiveness of human eye to the different image frequencies and contrasts. The 2D Rational dilation wavelet transform has been employed for representing image frequencies. In fact, it provides an adaptive and flexible multiresolution framework, enabling an easy and straightforward adaptation to the image frequency content. Preliminary experimental results show that the proposed preprocessing allows us to increase the performance of some standard image enhancement algorithms in terms of visual quality and often also in terms of PSNR

Body image perception and body composition: assessment of perception inconsistency by a new index

BACKGROUND: A correct perception of the body image, as defined by comparison with actual anthropometric analyses, is crucial to ensure the best possible nutritional status of each individual. Bioimpedance analysis (BIA) represents a leading technique to assess body composition parameters and, in particular, the fat mass. This study examined the self-perception of body image at various levels of adiposity proposing a new index. METHODS: We investigated 487 young Italian adults (mean age of males: 21.9 ± 2.4 years; mean age of females: 21.0 ± 2.2 years). Each subject could choose, on the Contour Drawing Rating Scale, the silhouette that he/she considered most resembling his/her perceived body image as well as his/her ideal body image. On each subject, we performed anthropometric measurements and determined the values of Fat mass and  út with BIA. A new index, FAIFAT (Feel fat status minus Actual fat status Inconsistency), was developed to evaluate possible fat status perception inconsistencies by BIA. RESULTS: Based on ideal and feel body image comparison, women showed higher dissatisfaction than men and preferred slimmer silhouettes. FAIFAT values indicated that the fat status perception was correct in the majority of the examined individuals and only three subjects showed a serious misperception. CONCLUSIONS: Our findings suggest that FAIFAT is an appropriate index for assessing the perceived fat status from the body image when compared with data obtained by BIA. In a population, the use of this index will allow the correct identification of groups at risk for eating disorders

Country Image, Perceived Product Quality and Purchase Intention: the Moderating Roles of Quality Warranty Certificate and Country-Image Transferred Strategies

This article aims at researching on the relationship of country image and customer perception on product quality and purchasing intention in South Korean. Additionally, the moderating roles of product quality warranty and country image transferred strategies are also taken into investigation in this empirical research. In order to make a research on these areas, questionnaire forms were distributed by emails and sending hard copies to 350 target samples in South Korea including Koreans and foreigners who have been living in South Korea and 215 forms were returned back and analyzed by SPSS v.21. The results indicated that gender, age groups and nationalities can significantly influence consumers' perception on the relationship country image and product quality. Surprisingly, the image of origin country produced products does not really affect consumers' perceived product quality, but the image of manufacturing country has a strong and significant influence on consumers' perception in terms of product quality. More interestingly, country image transferred strategy is ineffective in altering consumers' psychological perceptions on country image and perceived product quality. Apart from this, product quality warranty is still workable for boosting consumers' confidence in consuming products in Korean context. Even though this empirical research was considerably and carefully implemented, there are still some significant limitations in practice. The limitations and suggestion are finally introduced and explained

Image Perception

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Image management research

Two types of research issues are involved in image management systems with space station applications: image processing research and image perception research. The image processing issues are the traditional ones of digitizing, coding, compressing, storing, analyzing, and displaying, but with a new emphasis on the constraints imposed by the human perceiver. Two image coding algorithms have been developed that may increase the efficiency of image management systems (IMS). Image perception research involves a study of the theoretical and practical aspects of visual perception of electronically displayed images. Issues include how rapidly a user can search through a library of images, how to make this search more efficient, and how to present images in terms of resolution and split screens. Other issues include optimal interface to an IMS and how to code images in a way that is optimal for the human perceiver. A test-bed within which such issues can be addressed has been designed

Folding and Doubling: Revisiting Freud’s Screen Memories

The cinematic medium, according to Deleuze, enabled a new way of 'seeing' by relocating perception from the human eye to an 'eye in matter'. This paradigmatic shift away from a perception 'anchored in the subject' allowed for the image to be thought anew