Life Sciences Commons^™

Effects Of Removing Background Soil Reflectance Pixels From Vegetative Index Maps For Characterization Of Corn Responses To Experimental Treatments, Ana Morales, Robert L. Nielsen, James J. Camberato

Purdue GIS Day

In contrast to traditional data collection methods that require manual sampling, vegetative index (VI) maps derived from unmanned aerial vehicles (UAV) imagery are a potential tool to characterize temporal and spatial treatment effects in a more efficient and non-destructive way. Remotely-sensed reflectance data from a growing corn crop contains pixel values associated with the above-ground plant tissue (e.g., leaves, stalks, tassels) and the underlying soil features. Background soil reflectance data potentially reduces the effectiveness of VI for characterizing crop responses to experimental treatments. Removing background soil image pixels from the larger image dataset should improve that effectiveness. The objective of …

Quantifying Four Decades Of Arid-Region Agricultural Development In Arequipa, Peru Using Landsat, Zachary S. Brecheisen, Nicholas Hamp-Adams, Edwin Bocardo Delgado, Martin Villalta Soto, Timothy Filley, Darrell G. Schulze

Purdue GIS Day

The Arequipa Nexus Institute for Food, Energy and the Environment (Nexus Institute) is located in Southwestern Peru, generally bounded by the city of Arequipa to the east, the Majes River to the west, the Pacific Ocean to the south, and the Andes mountains to the north. Though agriculture has been practiced in parts of this cool desert region (MAT~15°C, MAP

Photogrammetric Measurement Of Hardwood Species At A Stand Level Using Rgb Images From Unmanned Aerial Vehicle (Uav), Aishwarya Chandrasekaran

Purdue GIS Day

Nowadays, for many remote sensing applications, drones are employed for gathering data, as it provides low cost image acquisition with minimal human intervention. Drone remote sensing has an extensive use in forestry for maintaining inventories, mapping canopy structure and monitoring forest fires. Maintaining a Forest inventory database is a crucial task as it is the only means of keeping a record of the trees. This study aims to explore UAV based image acquisition (consumer-grade sensor) and analysis for forest studies using structure from motion technique.The main objective is to derive a methodology for computing tree parameters such as tree height, …

Is The Selective Tuning Model Of Visual Attention Still Relevant?, John K. Tsotsos

MODVIS Workshop

No abstract provided.

Functional Organization Of Cortical Maps For Ocular Dominance And Light-Dark Polarity In Primary Visual Cortex, Sohrab Najafian, Jian Zhong Jin, Jose-Manuel Alonso

MODVIS Workshop

No abstract provided.

Computations Of Top-Down Attention By Modulating V1 Dynamics, David Berga, Xavier Otazu

MODVIS Workshop

The human visual system processes information defining what is visually conspicuous (saliency) to our perception, guiding eye movements towards certain objects depending on scene context and its feature characteristics. However, attention has been known to be biased by top-down influences (relevance), which define voluntary eye movements driven by goal-directed behavior and memory. We propose a unified model of the visual cortex able to predict, among other effects, top-down visual attention and saccadic eye movements. First, we simulate activations of early mechanisms of the visual system (RGC/LGN), by processing distinct image chromatic opponencies with Gabor-like filters. Second, we use a cortical …

Differentiating Changes In Population Encoding Models With Psychophysics And Neuroimaging, Jason Hays, Fabian Soto Phd

MODVIS Workshop

It is now common among visual scientists to make inferences about neural population coding of stimuli from indirect measures such as those provided by neuroimaging and psychophysics. The success of such studies depends strongly on simulation work using standard population encoding models extended with decoders (in psychophysics) and measurement models (in neuroimaging). However, not all studies are accompanied by simulation work, and those that are tend to vary widely in their assumptions about encoding, decoding, and measurement. To solve these issues, we designed a Python package (PEMGUIN) to assist computational modelling by providing simple ways to manage encoders' tuning functions, …

Explaining The Lightness Of Real Illuminated Surfaces Viewed Under Gelb Illumination With A Neurocomputational Model, Michael E. Rudd

MODVIS Workshop

No abstract provided.

Virtual Eye: A Spatial-Temporal Bottom-Up Eye Sensitivity Model, Todd Goodall

MODVIS Workshop

Video quality and compression models use the

spatial contrast sensitivity function (CSF), which is solved

based on a linear system approximation. This function measures

the eye’s sensitivity to sinusoid gratings, ignoring the subtle

connectivity and inhomogeniety of cell density across the

visual field. Non-linear aspects of the eye, such as the change

in frequency sensitivity with changing illumination, are not

captured by this simple approximation. We propose Virtual

Eye, a bottom-up approach that models the spatio-temporal

dynamics of the eye across the visual field. Each functional

retinal cell layer in the eye is modeled using non-uniform spatial

cell responses, which …

Variance Partitioning Reveals Consistent Representation Of Object Boundary Contours In Lo Across Different Datasets, Mark D. Lescroart, Utkarsh Singhal

MODVIS Workshop

No abstract provided.

The Challenge For Vision Of Fluctuating Real-World Illumination, David H. Foster

MODVIS Workshop

No abstract provided.

Improving Access To Clean Water Through Service Learning, Rachel E. Gehr, Tolu Odimayomi, Carolina Tornesi Mackinnon

Engagement & Service-Learning Summit

No abstract provided.