, Volume 54, Issue 4, pp 559–566 | Cite as

A novel method for the estimation of soybean chlorophyll content using a smartphone and image analysis

  • J. P. G. Rigon
  • S. Capuani
  • D. M. Fernandes
  • T. M. Guimarães
Original papers


The development of smartphones, specifically their cameras, and imaging technologies has enabled their use as sensors/measurement tools. Here we aimed to evaluate the applicability of a fast and noninvasive method for the estimation of total chlorophyll (Chl), Chl a, Chl b, and carotenoids (Car) content of soybean plants using a smartphone camera. Single leaf disc images were obtained using a smartphone camera. Subsequently, for the same leaf discs, a Chl meter was used to obtain the relative index of Chl and the photosynthetic pigments were then determined using a classic method. The RGB, HSB and CIELab color models were extracted from the smartphone images and correlated to Chl values obtained using a Chl meter and by a standard laboratory protocol. The smartphone camera was sensitive enough to capture successfully a broad range of Chl and Car contents seen in soybean leaves. Although there was a variation between color models, some of the proposed regressions (e.g., the S and b index from HSB and Lab color models and NRI [RGB model]) were very close to the Chl meter values. Based on our findings, smartphones can be used for rapid and accurate estimation of soybean and Car contents in soybean leaves.

Additional key words

camera color model mathematical models nondestructive photosynthetic pigments portable equipment 



mean values of blue






dark green color index


mean values of green


mean values of red


flovering stage


pod formation stage


vegetation index


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Copyright information

© The Institute of Experimental Botany 2016

Authors and Affiliations

  • J. P. G. Rigon
    • 1
  • S. Capuani
    • 2
  • D. M. Fernandes
    • 2
  • T. M. Guimarães
    • 1
  1. 1.Department of Crop Science, Lageado Experimental FarmSao Paulo State University (UNESP), College of Agricultural ScienceBotucatu, São PauloBrazil
  2. 2.Department of Soil and Environmental Resources, Lageado Experimental FarmSao Paulo State University (UNESP), College of Agricultural ScienceBotucatu, São PauloBrazil

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