The role of foveal and extrafoveal vision in the processing of scene semantics

This thesis investigated the ability to process semantic information from foveal and extrafoveal vision during scene viewing. Existing research suggested that object semantics could be detected from extrafoveal vision. This suggestion was investigated using three experimental paradigms. Semantic inconsistency was defined as a target semantically incompatible with scene gist. In Experiments 1 to 4, fixation position during a brief scene presentation was manipulated relative to a target object. The target's semantic inconsistency, presented foveally or extrafoveally, influenced performance on an object identification task. Extrafoveally presented semantically inconsistent targets were facilitated when simple line drawings were displayed, although this effect was unlikely to be mediated by semantic processing. No similar effect was found with complex line drawings or photographic stimuli. Experiments 5 and 6 attempted to replicate significant advantages for inconsistent targets in a change detection paradigm. However, no significant difference was found between performance for consistent and inconsistent targets in a two-exposure, forced-choice change detection task or an alternating display change detection task. There was no evidence that changing inconsistent targets were detected more reliably or earlier than changing consistent targets. Experiment 7 investigated the proposal that the extrafoveal processing of inconsistent objects could influence saccade patterns by attracting earlier fixations. Participants freely scanned both line drawings and photographs of scenes with no task. Again, no evidence was found supporting the earlier fixation of inconsistent objects in scenes. Therefore, this thesis could not confirm previous evidence of an inconsistent object advantage in either brief scene presentations, change detection or natural scene viewing. The evidence suggested that the preferential processing of inconsistent scene objects could occur under very limited circumstances, but would be unlikely to be mediated by semantic processing. When viewing complex, realistic scenes, there was no evidence of differential processing for consistent and inconsistent objects

Evaluation of changes in image appearance with changes in displayed image size

This research focused on the quantification of changes in image appearance when images are displayed at different image sizes on LCD devices. The final results provided in calibrated Just Noticeable Differences (JNDs) on relevant perceptual scales, allowing the prediction of sharpness and contrast appearance with changes in the displayed image size. A series of psychophysical experiments were conducted to enable appearance predictions. Firstly, a rank order experiment was carried out to identify the image attributes that were most affected by changes in displayed image size. Two digital cameras, exhibiting very different reproduction qualities, were employed to capture the same scenes, for the investigation of the effect of the original image quality on image appearance changes. A wide range of scenes with different scene properties was used as a test-set for the investigation of image appearance changes with scene type. The outcomes indicated that sharpness and contrast were the most important attributes for the majority of scene types and original image qualities. Appearance matching experiments were further conducted to quantify changes in perceived sharpness and contrast with respect to changes in the displayed image size. For the creation of sharpness matching stimuli, a set of frequency domain filters were designed to provide equal intervals in image quality, by taking into account the system’s Spatial Frequency Response (SFR) and the observation distance. For the creation of contrast matching stimuli, a series of spatial domain S-shaped filters were designed to provide equal intervals in image contrast, by gamma adjustments. Five displayed image sizes were investigated. Observers were always asked to match the appearance of the smaller version of each stimulus to its larger reference. Lastly, rating experiments were conducted to validate the derived JNDs in perceptual quality for both sharpness and contrast stimuli. Data obtained by these experiments finally converted into JND scales for each individual image attribute. Linear functions were fitted to the final data, which allowed the prediction of image appearance of images viewed at larger sizes than these investigated in this research

The effects of video compression on acceptability of images for monitoring life sciences experiments

Future manned space operations for Space Station Freedom will call for a variety of carefully planned multimedia digital communications, including full-frame-rate color video, to support remote operations of scientific experiments. This paper presents the results of an investigation to determine if video compression is a viable solution to transmission bandwidth constraints. It reports on the impact of different levels of compression and associated calculational parameters on image acceptability to investigators in life-sciences research at ARC. Three nonhuman life-sciences disciplines (plant, rodent, and primate biology) were selected for this study. A total of 33 subjects viewed experimental scenes in their own scientific disciplines. Ten plant scientists viewed still images of wheat stalks at various stages of growth. Each image was compressed to four different compression levels using the Joint Photographic Expert Group (JPEG) standard algorithm, and the images were presented in random order. Twelve and eleven staffmembers viewed 30-sec videotaped segments showing small rodents and a small primate, respectively. Each segment was repeated at four different compression levels in random order using an inverse cosine transform (ICT) algorithm. Each viewer made a series of subjective image-quality ratings. There was a significant difference in image ratings according to the type of scene viewed within disciplines; thus, ratings were scene dependent. Image (still and motion) acceptability does, in fact, vary according to compression level. The JPEG still-image-compression levels, even with the large range of 5:1 to 120:1 in this study, yielded equally high levels of acceptability. In contrast, the ICT algorithm for motion compression yielded a sharp decline in acceptability below 768 kb/sec. Therefore, if video compression is to be used as a solution for overcoming transmission bandwidth constraints, the effective management of the ratio and compression parameters according to scientific discipline and experiment type is critical to the success of remote experiments

The relationship between visual memory and rider expertise in a show-jumping context

Individuals develop visual skills while participating in sport. The aim of this study was to assess the effect of reported riding expertise on the recall of visual information relating to show-jumps. We identified a relevant (F1) and irrelevant (F2) point of focus in 22 photographs of show-jumps. Participants were students (n = 40) with varying levels of horse riding ability. The task, having viewed each photograph for four seconds, was to identify F1s or F2s from four alternatives viewed for ten seconds. F1s were recalled significantly more than F2s (P<0.001). Riding expertise did not affect overall recall but only intermediate/advanced riders recalled F1s significantly better than F2s (P<0.05 and P<0.001 respectively). Recall of F1s but not of F2s was significantly correlated with riding expertise (P<0.05). Training riders in visual attention techniques might improve ridden performance and could reduce the number of accidents associated with lack of experience and/or rider error

Application of ERTS-1 data to integrated state planning in the state of Maryland

There are no author-identified significant results in this report

Functional design for operational earth resources ground data processing

The author has identified the following significant results. Study emphasis was on developing a unified concept for the required ground system, capable of handling data from all viable acquisition platforms and sensor groupings envisaged as supporting operational earth survey programs. The platforms considered include both manned and unmanned spacecraft in near earth orbit, and continued use of low and high altitude aircraft. The sensor systems include both imaging and nonimaging devices, operated both passively and actively, from the ultraviolet to the microwave regions of the electromagnetic spectrum

An Overview of Remote Sensing in Russian Forestry

The Russian Federation possesses vast forested areas, containing about 23% of the world's closed forests. A significant part of these forestlands is neither managed nor regularly monitored. This is due in part to the absence of developed infrastructure in the remote northern regions, which hampers the collection of data on forest inventory and monitoring in all areas by precise and expensive on-ground methods. As a result, the monitoring in all areas by precise and expensive on-ground methods. As a result, the former Soviet Union conducted intensive research on remote sensing during the last few decades, resulting in significant achievements. However, there has been a noticeable decline in remote sensing research and applications in the Russian forest sector from 1990-1998. Russia needs a new system of forest inventory and monitoring capable of providing reliable, practical information for sustainable forest management. Such a system should take into account current national demands on the Russian forest sector as well as the international obligations of the country. Remote sensing methods are an indispensable part of such a system. These methods will play a crucial role in critical applications such as ensuring the sustainability of forest management, protecting threatened forests, fulfilling the countrys Kyoto Protocol obligations, and others. This paper presents an overview of past and current remote sensing methods in the Russian forest sector, including both practical and scientific applications. Based on this overview, relevant applications of remote sensing methods in the Russian forest sector are discussed. This discussion considers current Russian economic conditions and the direction of political and social development of the country

The Comprehensibility of Plain Language and Non Plain Language Minnesota Civil Jury Instructions

A substantial volume of research (e.g., Charrow & Charrow, 1979; Elwork, Sales & Alfini, 1977, 1982) suggests that jurors do not understand the often-convoluted language of standard jury instructions. Some states have recently simplified their instructions, but others continue to debate whether change is beneficial. This study was designed to investigate whether plain language jury instructions lead to improved comprehension. College students listened to either new, plain language Minnesota jury instructions or older Minnesota jury instructions addressing the same topics. Participants then took a written comprehension test covering legal rules contained in the instructions. Participants also completed a Nelson-Denny vocabulary test (Brown, Bennet, & Hanna, 1981) and provided demographic information. No significant treatment group differences were found for overall comprehension scores. Vocabulary scores were significantly correlated with comprehension scores for both groups of subjects. The results suggest that a juror\u27s verbal proficiency is more important in predicting comprehension of jury instructions than the language style of the instructions. Also, response patterns for some items suggest that people often maintain preconceived notions of legal rules despite clear instruction to the contrary

Lunar Photo Study, Phase 4 Final Report, 30 Nov. 1967 - 30 Nov. 1968

Lunar photo stud