scholarly journals sketcher: An R package for converting a photo into a sketch style image

2020 ◽  
Author(s):  
Hiroyuki Tsuda

Line drawings have been useful stimuli for visual perception, cognition, and related fields, because edges play an important role in the visual system. Although there are many datasets of line drawing stimuli available for research, we often need a new set of stimuli for specific research purposes. Here I provide an R implementation of image processing effects where a photo is converted to a line drawing image. Drawing style, such as lineweight, texture smoothness, and the inclusion of shading can be controlled by adjusting the parameters of this algorithm. With this tool, line drawing stimuli can easily be created with just a few lines of script, and will be useful for various research applications.

Perception ◽  
2020 ◽  
Vol 49 (4) ◽  
pp. 439-451 ◽  
Author(s):  
Aaron Hertzmann

Why is it that we can recognize object identity and 3D shape from line drawings, even though they do not exist in the natural world? This article hypothesizes that the human visual system perceives line drawings as if they were approximately realistic images. Moreover, the techniques of line drawing are chosen to accurately convey shape to a human observer. Several implications and variants of this hypothesis are explored.


Author(s):  
Klaus-Ruediger Peters

Differential hysteresis processing is a new image processing technology that provides a tool for the display of image data information at any level of differential contrast resolution. This includes the maximum contrast resolution of the acquisition system which may be 1,000-times higher than that of the visual system (16 bit versus 6 bit). All microscopes acquire high precision contrasts at a level of <0.01-25% of the acquisition range in 16-bit - 8-bit data, but these contrasts are mostly invisible or only partially visible even in conventionally enhanced images. The processing principle of the differential hysteresis tool is based on hysteresis properties of intensity variations within an image.Differential hysteresis image processing moves a cursor of selected intensity range (hysteresis range) along lines through the image data reading each successive pixel intensity. The midpoint of the cursor provides the output data. If the intensity value of the following pixel falls outside of the actual cursor endpoint values, then the cursor follows the data either with its top or with its bottom, but if the pixels' intensity value falls within the cursor range, then the cursor maintains its intensity value.


2012 ◽  
Vol 461 ◽  
pp. 215-219
Author(s):  
Yu Qian Zhao ◽  
Zhi Gang Li

According to the characteristics of infrared images, a contrast enhancement algorithm was presented. The principium of FPGA-based adaptive bidirectional plateau histogram equalization was given in this paper. The plateau value was obtained by finding local maximum and whole maximum in statistical histogram based on dimensional histogram statistic. Statistical histogram was modified by the plateau value and balanced in gray scale and gray spacing. Test data generated by single frame image, which was simulated by FPGA-based real-time adaptive bidirectional plateau histogram equalization. The simulation results indicates that the precept meet the requests well in both the image processing effects and processing speed


2021 ◽  
Vol 2091 (1) ◽  
pp. 012027
Author(s):  
V E Antsiperov ◽  
V A Kershner

Abstract The paper is devoted to the development of a new method for presenting biomedical images based on local characteristics of the intensity of their shape. The proposed method of image processing is focused on images that have low indicators of the intensity of the recorded radiation, resolution, contrast and signal-to-noise ratio. The method is based on the principles of machine (Bayesian) learning and on samples of random photo reports. This paper presents the results of the method and its connection with modern approaches in the field of image processing.


i-Perception ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 204166951875580 ◽  
Author(s):  
Jasmine Boshyan ◽  
Lisa Feldman Barrett ◽  
Nicole Betz ◽  
Reginald B. Adams ◽  
Kestutis Kveraga

Previous work using color photographic scenes has shown that human observers are keenly sensitive to different types of threatening and negative stimuli and reliably classify them by the presence, and spatial and temporal directions of threat. To test whether such distinctions can be extracted from impoverished visual information, we used 500 line drawings made by hand-tracing the original set of photographic scenes. Sixty participants rated the scenes on spatial and temporal dimensions of threat. Based on these ratings, trend analysis revealed five scene categories that were comparable to those identified for the matching color photographic scenes. Another 61 participants were randomly assigned to rate the valence or arousal evoked by the line drawings. The line drawings perceived to be the most negative were also perceived to be the most arousing, replicating the finding for color photographic scenes. We demonstrate here that humans are very sensitive to the spatial and temporal directions of threat even when they must extract this information from simple line drawings, and rate the line drawings very similarly to matched color photographs. The set of 500 hand-traced line-drawing scenes has been made freely available to the research community: http://www.kveragalab.org/threat.html .


Author(s):  
David Sidebotham ◽  
Alan Merry ◽  
Malcolm Legget ◽  
Gavin Wright

In Chapter 4, the 28 standard 2D TOE views, as recommended by the American Society of Echocardiography (ASE) and the Society of Cardiovascular Anesthesiologists (SCA), are described. For each view, a line drawing is provided, indicating relevant cardiac structures. Line drawings of normal spectral Doppler waveforms are also provided. 3D images of normal mitral, aortic, and tricuspid valves, displayed in their recommended orientations, are demonstrated. In addition to standard views, a sequential approach to performing a comprehensive TOE examination is described. Tables summarizing the indications and contraindications to TOE examination, as outlined by the ASE/SCA, are provided.


Author(s):  
Geoffrey M. Hudson ◽  
Yao Lu ◽  
Xiaoke Zhang ◽  
James Hahn ◽  
Johannah E. Zabal ◽  
...  

The creation of personalized avatars that may be morphed to simulate realistic changes in body size is useful when studying self-perception of body size. One drawback is that these methods are resource intensive compared to rating scales that rely upon generalized drawings. Little is known about how body perception ratings compare across different methods, particularly across differing levels of personalized detail in visualizations. This knowledge is essential to inform future decisions about the appropriate tradeoff between personalized realism and resource availability. The current study aimed to determine the impact of varying degrees of personalized realism on self-perception of body size. We explored this topic in young adult women, using a generalized line drawing scale, as well as several types of personalized avatars, including 3D textured images presented in immersive virtual reality (VR). Body perception ratings using generalized line drawings were often higher than responses using individualized visualization methods. While the personalized details seemed to help with identification, there were few differences among the three conditions containing different amounts of individualized realism (e.g., photo-realistic texture). These results suggest that using scales based on personalized texture and limb dimensions are beneficial, although presentation in immersive VR may not be essential.


2012 ◽  
Vol 5 (1) ◽  
pp. 1-10
Author(s):  
Mateusz Woźniak

Brain system responsible for visual perception has been extensively studied. Visual system analyses a wide variety of stimuli in order to let us create adaptive representation of surrounding world. But among vast amounts of processed information come visual cues describing our own bodies. These cues constitute our so-called body-image. We tend to perceive it as a relatively stable structure but recent research, especially within the domain of virtual reality, introduces doubts to this assumption. New problems appear concerning perceiving others’ and our own bodies in virtual space and how does it influence our experience of ourselves and true reality. Recent studies show that how we see our avatars influence how we behave in artificial worlds. It introduces a brand new way of thinking about human embodiment. Virtual reality allows us to transcend beyond the casual visual-sensory-motor integration and create new ways to experience embodiment, temporarily replacing permanent body image with almost any imaginable digital one. Santrauka Smegenų sistema, atsakinga už vizualųjį suvokimą, yra nuodugniai ištirta. Vizualioji sistema analizuoja plačią akstinų įvairovę, padedančią mums sukurti adaptuotą supančio pasaulio reprezentaciją. Tačiau tarp didelio kiekio apdorotos informacijos kyla vizualiosios užuominos, atvaizduojančios mūsų pačių kūnus. Šios užuominos steigia vadinamąjį kūną-atvaizdą. Mes linkstame jį suvokti kaip sąlygiškai stabilią struktūrą, tačiau dabartiniai tyrimai, o ypač tie, kurie vykdomi virtualiojoje realybėje, tokia prielaida verčia suabejoti. Kyla naujų problemų, suvokiant kitų ir mūsų pačių kūnus virtualiojoje erdvėje bei kokios įtakos tai turi mūsų pačių savęs ir tikrosios realybės patyrimui. Nūdieniai tyrinėjimai atskleidžia, kad tai, kaip mes suvokiame savąjį kūniškumą, turi įtakos tam, kaip elgiamės dirbtiniuose pasauliuose. Tai steigia visiškai naują žmogiškojo kūniškumo suvokimo būdą. Virtualioji realybė leidžia mums peržengti paprastą vizualinęjutiminę-motorinę integraciją ir kurti naujus būdus patirti kūniškumą, palaipsniui pakeičiant ilgalaikį kūno atvaizdą bet kokiu įsivaizduojamu skaitmeniniu.


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