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Abstract

The author describes the properties and mechanisms of visual perception in the context of their significance to the principles of symbol design as used in cartography. Map perception relies on the process of visual perception. Therefore, the knowledge of its inner workings in the map environment allows cartographers to construct cartographic symbols in agreement with the properties of the visual system.

Visual perception involves neurosensory processes taking place between the eye and the short-term memory. As such, they operate independently of the beholder’s consciousness and significantly influence the information received by the map user. The author discusses the mechanisms of human vision and the nature of the process of visual perception. It also shows the relationships between the image characteristic and the visual system’s properties such as the optical resolution, visual adaptation, reactions of inhibition and reinforcement, reactions to the image characteristics – as well as the phenomena of contrast, grouping and spatial arrangement.

The principles of constructing map symbols that have been developed in the long course of cartography, and based mostly on the map makers’ intuition, find validation in the light of properties and mechanisms of visual perception. As discussed in the paper, the fundamental properties and basic mechanisms of human vision support the view that knowledge of how the visual system works provides foundation for articulating new mapping guidelines and cartographers’ calls for stricter observance of cartographic principles are fully justified.

Abstract

In this paper we emphasize a similarity between the logarithmic type image processing (LTIP) model and the Naka–Rushton model of the human visual system (HVS). LTIP is a derivation of logarithmic image processing (LIP), which further replaces the logarithmic function with a ratio of polynomial functions. Based on this similarity, we show that it is possible to present a unifying framework for the high dynamic range (HDR) imaging problem, namely, that performing exposure merging under the LTIP model is equivalent to standard irradiance map fusion. The resulting HDR algorithm is shown to provide high quality in both subjective and objective evaluations.

Abstract

The terminal nerve (cranial nerve zero, cranial nerve XIII, the nerve “N”) was discovered in fish in 1894. In the early 90’s, it was found in human embryos and human adults. In the anterior fossa, it courses on the inner side of the olfactory tract and bulb; it then spreads fibers through the cribriform plate to distribute beneath the nasal septum mucosa. Being provided with intrinsic ganglion cells, its functions are weakly suggested by studies in different species. It may be connected with the visual system, it could act upon the intracranial vascular system, or it could ensure the pathway for pheromone-mediated behaviours. The cranial nerve zero deserves a better attention equally from anatomists and ENT specialists.

Abstract

There is insufficient information about the progress and variability of multiple sclerosis (MS). Afferent visual pathways are an appropriate MS clinical model. Optical coherence tomography (OCT) allows to perform precise measurements of axonal tissue in the retinal nerve fibre layer (RNFL). Visual evoked potentials (VEP) provide information about the functional status of visual pathways. The aim of our study was to use OCT and VEP to evaluate MS patients with and without optic neuritis (ON) history and to determine relationships between functional and structural changes. The cross-sectional study included 76 relapsing-remitting MS patients and 28 healthy controls. The lowest mean VEP N75/P100 amplitude was found in ON affected eyes (8.16 mkV, SD = 4.60). However, it was observed that the mean amplitude in patients without ON (M = 9.86; SD = 4.63) was by 4.64 mkV lower than in controls (p < 0.001). Similarly, the mean P 100 latency in ON eyes was 9.26 ms longer than in eyes of patients without ON history (p < 0.01). RNFL in the temporal segment (RNFLT) was the thinnest in ON eyes, and even in patient eyes without ON, it was thinner than in controls. We found a significant positive correlation between RNFLT and mean N75/P100 amplitude in patients without ON (rs = 0.43; p < 0.001), and after ON (rs = 0.45; p < 0.001). Both in patients without ON (rs = -0.40; p < 0.001) and in ON eyes we found a significant negative correlation (rs = -0.55; p > 0.001) between RNFLT and mean P100 latency. In summary, we found that deterioration in the visual system was not associated with the clinical ON episode. Regardless of ON symptoms in history, there exists correlation between functional and structural changes.

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This paper presents a navigation method for a mobile robot using a visual system. Circular marks with specific colors are used for marking the significant points of the mobile robot’s trajectory that it needs to pass. The colors of the used marks are signalizing the way of their bypassing with the mobile robot (from the left or right side). The mobile robot uses only one camera for the marks recognition task and it is able to determine its own relative position from the detected marks. The image processing and the mobile robot’s trajectory planning algorithm working in real-time are described in this paper.

Abstract

The paper presents an attempt to create a system for visual surveillance for movement rehabilitation. The Delaunay triangulation was used as a key method for skeletonization of detected human silhouette. Also, the Hough transform was performed on skeletons of selected body parts in order to obtain slants of those body parts. Analysis of slant changes gives information of movement range, number of exercise repetitions and in general, to assessing correctness of performed exercises. The presented results show that - under some circumstances - it is possible to create visual system for such task.

Abstract

Automatic detection of objects is a part of visual systems supporting a quality control system of a manufacturing process. The paper concerns the influence of the resolution of images and the size of detected objects in pixels on measurements results. Test images of the objects of a known size were generated. The values of the perimeter of the objects were compared to the obtained values of measurements on the images with degraded resolution. The process of the degradation of the references images by successive downsizing the resolution, detection and measurements were performed applying automatic algorithm. The analysis of obtained results showed that the size of the analysed objects on the digital images plays an important role in reliability and accuracy of the measurement. The author concludes that, in order to avoid a bias in measurement caused by insufficient object resolution, the minimal acceptable size of objects on digital images in pixels should be recommended.