161,450 research outputs found
Some remarks on the visual angle metric
We show that the visual angle metric and the triangular ratio metric are
comparable in convex domains. We also find the extremal points for the visual
angle metric in the half space and in the ball by use of a construction based
on hyperbolic geometry. Furthermore, we study distortion properties of
quasiconformal maps with respect to the triangular ratio metric and the visual
angle metric.Comment: 13 pages, 5 picture
LAPR: An experimental aircraft pushbroom scanner
A three band Linear Array Pushbroom Radiometer (LAPR) was built and flown on an experimental basis by NASA at the Goddard Space Flight Center. The functional characteristics of the instrument and the methods used to preprocess the data, including radiometric correction, are described. The radiometric sensitivity of the instrument was tested and compared to that of the Thematic Mapper and the Multispectral Scanner. The radiometric correction procedure was evaluated quantitatively, using laboratory testing, and qualitatively, via visual examination of the LAPR test flight imagery. Although effective radiometric correction could not yet be demonstrated via laboratory testing, radiometric distortion did not preclude the visual interpretation or parallel piped classification of the test imagery
Size-induced distortions in perceptual maps of visual space
In order to interact with our environment, the human brain constructs maps of visual space. The orderly mapping of external space across the retinal surface, termed retinotopy, is maintained at subsequent levels of visual cortical processing and underpins our capacity to make precise and reliable judgments about the relative location of objects around us. While these maps, at least in the visual system, support high precision judgments about the relative location of objects, they are prone to significant perceptual distortion. Here, we ask observers to estimate the separation of two visual stimuliVa spatial interval
discrimination task. We show that large stimulus sizes require much greater separation in order to be perceived as having the same separation as small stimulus sizes. The relationship is linear, task independent, and unrelated to the perceived position of object edges. We also show that this type of spatial distortion is not restricted to the object itself but can also be revealed by changing the spatial scale of the background, while object size remains constant. These results indicate that fundamental spatial properties, such as retinal image size or the scale at which an object is analyzed, exert a marked influence on spatial coding
Distortion-Guided Mesh Processing
Mesh processing algorithms have the potential to perform better when being guided by a distortion metric. Some mesh processing algorithms can take advantage of such guidance and produce better results, while maintaining high visual quality. Mesh geometry decimation and texture coordinate generation are candidate algorithms to be guided by the distortion metric. An additional motivation is to provide a convenient way to visualize the most distorted areas on mesh surface in 3D space
Perception-Distortion Trade-off in the SR Space Spanned by Flow Models
Flow-based generative super-resolution (SR) models learn to produce a diverse
set of feasible SR solutions, called the SR space. Diversity of SR solutions
increases with the temperature () of latent variables, which introduces
random variations of texture among sample solutions, resulting in visual
artifacts and low fidelity. In this paper, we present a simple but effective
image ensembling/fusion approach to obtain a single SR image eliminating random
artifacts and improving fidelity without significantly compromising perceptual
quality. We achieve this by benefiting from a diverse set of feasible
photo-realistic solutions in the SR space spanned by flow models. We propose
different image ensembling and fusion strategies which offer multiple paths to
move sample solutions in the SR space to more desired destinations in the
perception-distortion plane in a controllable manner depending on the fidelity
vs. perceptual quality requirements of the task at hand. Experimental results
demonstrate that our image ensembling/fusion strategy achieves more promising
perception-distortion trade-off compared to sample SR images produced by flow
models and adversarially trained models in terms of both quantitative metrics
and visual quality.Comment: 5 pages, 4 figures, accepted for publication in IEEE ICIP 2022
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Improving memorability in fisheye views
Interactive fisheye views use distortion to show both local detail and global context in the same display space. Although fisheyes allow the presentation and inspection of large data sets, the distortion effects can cause problems for users. One such problem is lack of memorability – the ability to find and go back to objects and features in the data. This thesis examines the possibility of improving the memorability of fisheye views by adding historical information to the visualization. The historical information is added visually through visit wear, an extension of the concepts of edit wear and read wear. This will answer the question “Where have I been?” through visual instead of cognitive processing by overlaying new visual information on the data to indicate a user’s recent interaction history. This thesis describes general principles of visibility in a space that is distorted by a fisheye lens and defines some parameters of the design space of visit wear. Finally, a test system that applied the principles was evaluated, and showed that adding visit wear to a fisheye system improved the memorability of the information space
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