The Diagnosis of Optimal Harvesting Time of Rice Using Digital Imaging

Iwaya, Kiyoshi; Yamamoto, Haruhiko

doi:10.2480/agrmet.981

Cited by 8 publications

(5 citation statements)

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“…The resolution of images was 300 dpi and 3000×2000 pixels. According to the known researches (Adamsen 1999;Iwaya 2005;Cai 2006) and the screening of indices in this research, the G/R and G/L values were selected for RGB image analysis. The Red (R), Green (G) and Luminance (L) values were read from the average histogram value of leaves selected by Magic Wand Tool of Photoshop.…”

Section: Research Papermentioning

confidence: 99%

“…In the research of wheat and rye, Kawashima et al (1998) considered the normalized difference (red-blue)/(red+blue) was the most applicable function using data collected under different meteorological conditions by portable video camera. Iwaya et al (2005) measured water content of wheat panicle by (R-G)/(R+G) value etc. Suzuki et al (1999) used the G/(R+G+B) for broccoli identification.…”

Section: Introductionmentioning

confidence: 99%

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Measuring leaf necrosis and chlorosis of bamboo induced by typhoon 0613 with RGB image analysis

Wang

Yamamoto

Ibaraki

2008

Journal of Forestry Research

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Symptoms of leaf necrosis or chlorosis of bamboo induced by Typhoon 0613 (T0613) were analyzed using RGB image analysis in Yamaguchi city, Japan. Results showed a closely positive relationship between Green/Red (G/R) value for indoor taking images of bamboo individual leaves and chlorophyll meter value (SPAD) with regression coefficient of 0.961. The relation between G/R value of room taking images and Necrotic Area Percentage (NAP) for bamboo individual leaves showed an inverse logistic function relationship, with the correlated coefficient equaling to 0.958. Both leaf chlorosis and necrosis can be quantitatively estimated by RGB image analysis. Moreover,the variance of Green/Luminance (G/L) value for the same leaf was less than that of G/R for images taken in the conditions with large light difference, especially for green leaves. G/L value also exhibited a closer relationship with SPAD value of leaves with chlorosis than that of G/R values at the same condition. The relationship between G/L value for bamboo canopies and the Distance from Coastline (DC) was also closer than that of the G/R value for the images taken at field sites with big light difference.

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Section: Research Papermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Measuring leaf necrosis and chlorosis of bamboo induced by typhoon 0613 with RGB image analysis

Wang

Yamamoto

Ibaraki

2008

Journal of Forestry Research

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“…As further indicated by the authors, modern agricultural management makes use of different sensing technologies to provide accurate information on crop, soil, climate, and environmental conditions. Therefore, digital devices or ICTs had long been integrated in agricultural research, thereby making it possible to have fundamental and site-specific data collection which is definitely necessary for some specific decision-supports ranging from updates of weather conditions, soil nutrient status, pest management, modeling of genetic lines of plants, and livestock for adaptation to various conditions and animal production (Iwaya & Yamamoto, 2005;Zhang, Li, Zhou, & Moore, 2002).…”

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confidence: 99%

Essentialities of Digital Technology Incorporation in Research Tasks by Agro-Researchers in the Southwest Nigerian Farming Zone

Lawal-Adebowale

2017

International Journal of ICT Research in Africa and the Middle East

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The study examined the incorporation of digital technologies in the Nigerian agricultural research system and showed that digital technologies such as digital balance, digital pH meter, phone sensors, and the Global Positioning System (GPS) and the Geographic Information System (GIS), among others, had a high rate of incorporation in agro-research activities in the southwest farming zone of Nigeria. Determinants of such incorporation in agro-research activities were accuracy of data collection, enhancement of research task execution, improvement of research quality, usage convenience and portability of the devices, convenience of usage for data storage, and ease of data retrieval. The Spearman rho correlation test showed a significant correlation between the use of digital oven and its ready availability/accessibility (r = 0.168); digital pH meter and convenient of data storage on the device (r = 0.157); Spectrophotometer and convenient of data storage (r = -0.161); phone sensors and ready availability/accessibility of the device (r = 0.156); use of GPS/GIS and convenience of usage of the devices (r = -0.173) at p<0.05 level. It concluded that only a few of the digital technologies were readily incorporated in research activities by the Nigerian agro-researchers. It was also recommended that application of digital devices in agro-research activities should be intensified for agro-research development in the country.

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“…It can be considered as an improved G/(R G B) value fitting the bright environment. Iwaya and Yamamoto (2005) studied the relationship between the panicle water content of paddy rice with 19 color indices, in which the G/L value was the highest one related to panicle water content of paddy rice in 1998 with R 2 0.919. Whether or not it can be used in determining the ginkgo leaf necrosis and asymmetric crown discoloration is needed to make clear.…”

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Evaluating Ginkgo Leaf Necrosis and Asymmetric Crown Discoloration Induced by Typhoon 0613 with RGB Image Analysis

Wang¹,

Yamamoto²,

Ibaraki³

et al. 2009

J. Agric. Meteorol.

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As one kind of disaster, typhoons can cause serious damage to landscape trees both mechanically and physiologically. The Typhoon 0613 was characterized by strong wind associated with less rainfall when it passed through Yamaguchi City, Japan. After hit by it, the symptoms of leaf necrosis appeared on many ginkgo trees from coast to inland and the crowns of them became asymmetrically discolored. Due to the big body of ginkgo trees, this kind of phenomenon was often described by visual scale method characterized by significant deviation and observer specific. In order to quantitatively estimate the symptoms of damage, the leaf necrotic area percentage (LNAP), crown discoloration area percentage (CDAP) and inflection point (IP) of the threshold response function for asymmetric discolored crowns were determined by image pixel method. The green/luminance (G/L) value was measured by using the RGB images respectively scanned by a flat bed scanner from individual leaves and taken with a CCD digital camera from crowns. Significant relationship between G/Lleaf and LNAP, and between G/Lcrown and CDAP were obtained with the correlation coefficient of R 2 0.941 and R 2 0.826 separately. This suggested that both leaf necrosis and asymmetric crown discoloration of ginkgo trees induced by Typhoon 0613 can be quantitatively estimated by measuring the G/L value from both leaves and crowns. The significant relation between CDAP and IP (R 2 0.811) reveals that both statistically calculated IP value and visually divided CDAP value can be used in estimating the asymmetric crown characters. The estimation of sampled leaves showed that it was the difference of necrotic leaves between windward and leeward made the crown of damaged ginkgo trees appear asymmetrical discoloration. Image threshold responsive analysis of ginkgo crowns hit by Typhoon 0613 indicated that the injury of ginkgo crowns was more serious on windward than leeward. The relationship between the distance from coastline (DC) and G/Lcrown value presented that the farther from the coastline, the bigger the G/Lcrown value of ginkgo crowns. Comparing to the sampling method, image analysis can be more effective being applied in field measurement of damaged status of ginkgo trees hit by severe typhoons for the reason of less labor and less time requirement. It may be an alternative tool to be used in estimating the degree of damage to ginkgo trees by typhoons like Typhoon 0613.

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The Diagnosis of Optimal Harvesting Time of Rice Using Digital Imaging

Cited by 8 publications

References 4 publications

Measuring leaf necrosis and chlorosis of bamboo induced by typhoon 0613 with RGB image analysis

Measuring leaf necrosis and chlorosis of bamboo induced by typhoon 0613 with RGB image analysis

Essentialities of Digital Technology Incorporation in Research Tasks by Agro-Researchers in the Southwest Nigerian Farming Zone

Evaluating Ginkgo Leaf Necrosis and Asymmetric Crown Discoloration Induced by Typhoon 0613 with RGB Image Analysis

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