Classification of Individual Castor Seeds Using Digital Imaging and Multivariate Analysis

Chemometrics‐assisted color histogram‐based analytical systems

“…This step has been performed in the offline mode in practically all publications reviewed here. However, in most recent approaches, 48,51,58 a smartphone that aggregates the camera and the software for control and image processing have been also employed, which contributes towards the development of truly portable systems. A good example is the PhotoMetrix®, 62 a free application for mobile devices that uses univariate calibration by simple linear regression method and multivariate analysis by principal component analysis (PCA), hierarchical clustering analysis (HCA), and partial least squares (PLS), being this last two available only in its PRO version.…”

“…3 An image capturing device to register the images of the chemical system under consideration. Simple commercial devices include digital cameras, 15,25,30,41,45,52,53,59,60 scanners, 21,28,34,35,39,43,46,[54][55][56][57]61 webcams, 26,29,32,33,[36][37][38]40,42,44,[47][48][49] and smartphones, 17,18,27,31,50,51,58 and the choice of one of them shall be according to its availability in each laboratory or specific need for a given application. However, it is important to note that the portability of systems through the use of smartphones has become a remarkable trend in the literature, mainly in applications involving univariate calibration for colorimetric analysis.…”

“…An exception is when using scanners, which already have a shield cover to prevent external interferences, or a protective box 39 can be also adapted for this same purpose. An image capturing device to register the images of the chemical system under consideration. Simple commercial devices include digital cameras, 15,25,30,41,45,52,53,59,60 scanners, 21,28,34,35,39,43,46,54–57,61 webcams, 26,29,32,33,36–38,40,42,44,47–49 and smartphones, 17,18,27,31,50,51,58 and the choice of one of them shall be according to its availability in each laboratory or specific need for a given application. However, it is important to note that the portability of systems through the use of smartphones has become a remarkable trend in the literature, mainly in applications involving univariate calibration for colorimetric analysis. A computer containing a software for extraction of the color histograms from the registered images and other for construction of the chemometric models.…”

“…Vilar et al 48 classified the cultivar type of individual castor seeds according to two groups, being the group I composed of BRS Nordestina and BRS Paraguaçu cultivars and the group II containing BRS Energia cultivar and CNPA 2009‐7 genotype. PLS‐DA classified correctly 97.5% and 98.8% of the prediction samples for groups I and II using grayscale + RGB + HSI and red histograms, respectively.…”

“…PTFE chambers of automated Flow-Batch Analyzers 26,47 have been also used to prepare samples and calibration solutions in flow into the mixing chamber. Other specific holders have been also designed in the laboratory for dedicated applications, such as panel for paint, 21 lab-made PTFE supports, 48,49 white A4 paper, 50 polyethylene bottle, 51 paper tray, 52 lab-made rubber ring, 15 immobilized calcium-alginate capsule, 53 ELISA (enzyme-linked immunosorbent assay) microplate, [54][55][56] thin layer chromatographic (TLC) plate, 18 glass vial, 57 lab-made PTFE cell, 58 test tube, 59 stage plate, 60 and kraft tapes. 61 2 An illumination source emitting a broad range of visible wavelengths (white light) has been employed to illuminate uniformly the holder.…”