scholarly journals Tilt correction method of text image based on wavelet pyramid

2017 ◽  
Author(s):  
Mingyang Yu ◽  
Qiguo Zhu
Keyword(s):  
Correction Method ◽  
Tilt Correction ◽  
Wavelet Pyramid

scholarly journals A Novel Tilt Correction Technique for Irradiance Sensors and Spectrometers On-Board Unmanned Aerial Vehicles

2018 ◽  
Vol 10 (12) ◽  
pp. 2068 ◽  
Author(s):  
Juha Suomalainen ◽  
Teemu Hakala ◽  
Raquel Alves de Oliveira ◽  
Lauri Markelin ◽  
Niko Viljanen ◽  
...  
Keyword(s):  
Real Time ◽  
Remote Sensing Data ◽  
Correction Method ◽  
Aerial Images ◽  
Aerial Image ◽  
Optical Remote Sensing ◽  
Processing Unit ◽  
Atmospheric Conditions ◽  
Tilt Correction ◽  
Correction Technique

In unstable atmospheric conditions, using on-board irradiance sensors is one of the only robust methods to convert unmanned aerial vehicle (UAV)-based optical remote sensing data to reflectance factors. Normally, such sensors experience significant errors due to tilting of the UAV, if not installed on a stabilizing gimbal. Unfortunately, such gimbals of sufficient accuracy are heavy, cumbersome, and cannot be installed on all UAV platforms. In this paper, we present the FGI Aerial Image Reference System (FGI AIRS) developed at the Finnish Geospatial Research Institute (FGI) and a novel method for optical and mathematical tilt correction of the irradiance measurements. The FGI AIRS is a sensor unit for UAVs that provides the irradiance spectrum, Real Time Kinematic (RTK)/Post Processed Kinematic (PPK) GNSS position, and orientation for the attached cameras. The FGI AIRS processes the reference data in real time for each acquired image and can send it to an on-board or on-cloud processing unit. The novel correction method is based on three RGB photodiodes that are tilted 10° in opposite directions. These photodiodes sample the irradiance readings at different sensor tilts, from which reading of a virtual horizontal irradiance sensor is calculated. The FGI AIRS was tested, and the method was shown to allow on-board measurement of irradiance at an accuracy better than ±0.8% at UAV tilts up to 10° and ±1.2% at tilts up to 15°. In addition, the accuracy of FGI AIRS to produce reflectance-factor-calibrated aerial images was compared against the traditional methods. In the unstable weather conditions of the experiment, both the FGI AIRS and the on-ground spectrometer were able to produce radiometrically accurate and visually pleasing orthomosaics, while the reflectance reference panels and the on-board irradiance sensor without stabilization or tilt correction both failed to do so. The authors recommend the implementation of the proposed tilt correction method in all future UAV irradiance sensors if they are not to be installed on a gimbal.

scholarly journals Tilt Correction Method of Pointer Meter Based on Deep Learning

2020 ◽  
Vol 32 (12) ◽  
pp. 1976-1984
Author(s):  
Dengke Zhou ◽  
Ying Yang ◽  
Jie Zhu ◽  
Ku Wang
Keyword(s):  
Deep Learning ◽  
Correction Method ◽  
Tilt Correction

scholarly journals A Horizontal Tilt Correction Method for Ship License Numbers Recognition

2018 ◽  
Vol 976 ◽  
pp. 012013 ◽  
Author(s):  
Baolong Liu ◽  
Sanyuan Zhang ◽  
Zhenjie Hong ◽  
Xiuzi Ye
Keyword(s):  
Correction Method ◽  
Tilt Correction

scholarly journals Study on the Technique of Ellipse Excavation and Tilt Correction of the Stone Statues of the Northern Song Dynasty Imperial Mausoleum

2021 ◽  
Author(s):  
Qingwen Ma ◽  
yangyang wang ◽  
Sihan Liu ◽  
Xinyu Fan
Keyword(s):  
Song Dynasty ◽  
Correction Method ◽  
Tilt Correction ◽  
Northern Song Dynasty ◽  
Low Weight ◽  
Northern Song ◽  
Building Area ◽  
Simulation And Experiment ◽  
Soil Excavation ◽  
Small Building

Abstract This article takes the stone statues of the Northern Song Dynasty imperial mausoleum as the research object. Aiming at the characteristics of the stone statues low weight and small building area, combined with the serious weathering of the stone statues, the reasons for the inclination and the defects of the traditional round soil excavation holes, an elliptical soil excavation correction method is proposed. Adopt the method of combining numerical simulation and experiment to carry out the research of elliptical excavation and tilt correction of stone statues. Research indicates: The settlement difference between the excavation side and the non-excavation side increases with the increase of the span-to-height ratio of the excavation hole; The shallower the depth of the digging hole, the greater the settlement difference between the digging side and the non-digging side; The settlement difference between the digging side and the non-digging side decreases with the increase of the hole spacing; The settlement of the superstructure mainly occurs within 4 to 5 hours after the soil is excavated, and then enters a slow growth stage, and finally gradually stabilizes; During the test, the failure of the digging hole belongs to plastic failure. The damage of the digging hole is firstly destroyed from both sides of the hole, and the upper part of the hole is destroyed immediately, and the upper structure edge is destroyed first.

scholarly journals Quality Control and Tilt Correction Effects on the Turbulent Fluxes Observed at an Ocean Platform

2011 ◽  
Vol 50 (3) ◽  
pp. 700-712 ◽  
Author(s):  
Hyun-Mi Oh ◽  
Kyung-Eak Kim ◽  
Kyung-Ja Ha ◽  
Larry Mahrt ◽  
Jae-Seol Shim
Keyword(s):  
Quality Control ◽  
Fast Response ◽  
Correction Method ◽  
Turbulent Fluxes ◽  
The Yellow Sea ◽  
Research Station ◽  
Tilt Correction ◽  
Stable Conditions ◽  
Sonic Anemometers ◽  
Atmospheric Factors

Abstract This study investigates atmospheric factors influencing the quality and the postprocessing (e.g., tilt correction) of fast-response measurements of turbulent fluxes for difficult open-sea measurements over an offshore platform. The data were collected at the Ieodo Ocean Research Station over the Yellow Sea during the period from 5 November 2007 to 19 February 2008. The quality control removal of the data generally depends on wind speed, relative humidity, significant wave height, visibility, and stability. The removal of substantial water vapor data with weak-wind stable conditions is investigated. Three different tilt correction algorithms (double rotation, triple rotation, and planar fit) are applied to correct the data because of inadvertent tilt of sonic anemometers. The choice of tilt correction method significantly influences the angle between the wind and stress direction.

Ortho-k lenses fitting in patients with “non-typical” corneas

The Eye ◽  
2020 ◽  
Vol 22 (129) ◽  
pp. 22-29
Author(s):  
Svetlana Kravchuk ◽  
Olga Zhabina
Keyword(s):  
Correction Method ◽  
Diameter Ratio ◽  
Corneal Curvature ◽  
Individual Approach ◽  
Fitting In ◽  
Corneal Diameter ◽  
Clinical Cases

We described two clinical cases of ortho-k lenses fitting in patients with “non-typical” corneal curvature/diameter ratio. The main goal was to acknowledge effective and safe use of this myopia correction method in patients with corneal diameter greater than 11 mm. Individual approach to each patient is the key to a successful and safe ortho-k lenses fitting.

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