Method and device for utilizing digital camera to obtain rice canopy leaf area index

Abstract

The invention discloses a method and a device for utilizing a digital camera to obtain rice canopy leaf area index. The method includes the following steps: (1) the digital camera is arranged above the outer portion of a rice canopy, a lens faces downward, a lens primary optical axis is perpendicular to a rice canopy horizontal projection plane, and a rice canopy original color image is shot; (2) the rice canopy original color image is converted into a gray level image; (3) the gray level image is converted into a binary image only containing a black image element and a white image element; (4) rice canopy porosity is extracted from the binary image; and (5) the leaf area index is calculated according to the extracted rice canopy porosity. According to the device and the method, only a common digital camera is needed to shoot a rice canopy image above the outer portion of the rice canopy in vertical overlook mode, manual measurement through destructive picking of rice leaves in the field is not needed, the rice canopy leaf area index (LAI) can be obtained rapidly in real time, and basic parameters are provided for rice remote yield estimation and rice growing condition monitoring.

Description

technical field [0001] The invention relates to the technical field of rice canopy leaf area index measurement, in particular to a method and a device for obtaining rice canopy leaf area index LAI by using a digital camera. Background technique [0002] Rice is one of the most important food crops in my country and occupies a very important position in the national food security strategy. Rice leaves are the only site where many biophysical processes in rice, including photosynthesis, respiration, transpiration, and precipitation interception, take place. Leaf area index (LAI) reflects the total area of ​​rice leaves per unit surface, which determines the ability of rice to utilize and manage solar radiation and water. Therefore, LAI is an important indicator to reflect rice growth, nutritional status, and estimate rice yield. [0003] The traditional method of obtaining rice LAI is mainly "direct measurement method". Leaf area index was converted from the total leaf area...

AI Technical Summary

Problems solved by technology

However, as imported instruments, their prices are relatively expensive, which is not conducive to the widespread use in our country

In addition, these instruments themselves also have some inconveniences

For example, these instruments require to collect radiation information from the bottom of the canopy upwards. For plants in the early growth stage or plants with a low canopy height (such as rice), due to the thickness of the instrument (or probe) itself, it is impossible to obtain a complete canopy information

Moreover, some instruments must collect the radiation information above and below the canopy twice, which is not conducive to fixing the instrument on a mobile device (tractor, etc.) to collect large-area LAI data

[0007] Based on the ordinary digital camera to shoot the rice canopy image vertically and extract the porosity to invert the rice leaf area index, there is no report in the public literature at home and abroad

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