scholarly journals A new approach of feature-based asteroid taxonomy in 3D color space. I. SDSS photometric system

Author(s):  
D.-G. Roh ◽  
H.-K. Moon ◽  
M.-S. Shin ◽  
F. E. DeMeo
2020 ◽  
Vol 2020 (1) ◽  
pp. 100-104
Author(s):  
Hakki Can Karaimer ◽  
Rang Nguyen

Colorimetric calibration computes the necessary color space transformation to map a camera's device-specific color space to a device-independent perceptual color space. Color calibration is most commonly performed by imaging a color rendition chart with a fixed number of color patches with known colorimetric values (e. g., CIE XYZ values). The color space transformation is estimated based on the correspondences between the camera's image and the chart's colors. We present a new approach to colorimetric calibration that does not require explicit color correspondences. Our approach computes a color space transformation by aligning the color distributions of the captured image to the known distribution of a calibration chart containing thousands of colors. We show that a histogram-based colorimetric calibration approach provides results that are onpar with the traditional patch-based method without the need to establish correspondences.


2020 ◽  
Vol 12 (14) ◽  
pp. 2229
Author(s):  
Haojie Liu ◽  
Hong Sun ◽  
Minzan Li ◽  
Michihisa Iida

Maize plant detection was conducted in this study with the goals of target fertilization and reduction of fertilization waste in weed spots and gaps between maize plants. The methods used included two types of color featuring and deep learning (DL). The four color indices used were excess green (ExG), excess red (ExR), ExG minus ExR, and the hue value from the HSV (hue, saturation, and value) color space, while the DL methods used were YOLOv3 and YOLOv3_tiny. For practical application, this study focused on performance comparison in detection accuracy, robustness to complex field conditions, and detection speed. Detection accuracy was evaluated by the resulting images, which were divided into three categories: true positive, false positive, and false negative. The robustness evaluation was performed by comparing the average intersection over union of each detection method across different sub–datasets—namely original subset, blur processing subset, increased brightness subset, and reduced brightness subset. The detection speed was evaluated by the indicator of frames per second. Results demonstrated that the DL methods outperformed the color index–based methods in detection accuracy and robustness to complex conditions, while they were inferior to color feature–based methods in detection speed. This research shows the application potential of deep learning technology in maize plant detection. Future efforts are needed to improve the detection speed for practical applications.


Author(s):  
J. M. Soto-Hidalgo ◽  
J. Chamorro-Martinez ◽  
D. Sanchez
Keyword(s):  

2014 ◽  
Vol 14 (10) ◽  
pp. 21-21
Author(s):  
V. S. Stormer ◽  
G. A. Alvarez

Author(s):  
Sang Hun Lee ◽  
Kyu-Yeul Lee

The requirements of multi-resolution models of feature-based solids, which represent an object at many levels of feature detail, are increasing for engineering purposes, such as analysis, network-based collaborative design, virtual prototyping and manufacturing. To provide multi-resolution models for various applications, it is essential to generate adequate solid models at varying levels of detail (LOD) after feature rearrangement, based on the LOD criteria. However, the non-commutative property of the union and subtraction Boolean operations is a severe obstacle to arbitrary feature rearrangement. To solve this problem we propose a new approach based on the non-manifold topological representation and the merge-and-select algorithm for non-manifold Boolean operations. In this approach, the merge-and-select algorithm is modified to satisfy the commutative law between union and subtraction operations by considering the history of the Boolean operations. Because this algorithm guarantees the same resulting shape as the original and reasonable shapes at the intermediate LODs for an arbitrary rearrangement of its features, various LOD criteria can be applied for multiresolution modeling in different applications.


2012 ◽  
Vol 41 ◽  
pp. 305-311 ◽  
Author(s):  
Reza Javanmard Alitappeh ◽  
Kossar Jeddi Saravi ◽  
Fariborz Mahmoudi

Author(s):  
Subramanian Krishnan ◽  
Edward B. Magrab

Abstract An integrated design for manufacture system for milling is developed by introducing a fundamental manufacturing entity for milling (FMEM), which represents a volume to be machined. A part is created by subtracting a user created set of FMEMs from a rectangular prismatic stock. Manufacturability evaluation is done in two stages: (1) after creating each FMEM; and (2) after placing and subtracting the volume from the stock. It is shown that the commonly used 2½ -D features used to mill a part such as slots, pockets and holes are a subset of the FMEM. Furthermore, all specific shapes of the general FMEM are represented by one compact data structure. It is demonstrated that using process specific entities greatly simplifies manufacturability evaluation, which makes it possible to base the geometric reasoning algorithms on the entity’s most general profile rather than on only a set of specific shapes. A new approach using the FMEMs is presented for generating an integrated process and fixture plan with a minimum number of setup and tool changes. The advantages of using the process specific entities approach for design and manufacturability analysis over the feature recognition approach and feature based approach are enumerated.


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