Detection of Fecal Contamination on Cantaloupes Using Hyperspectral Fluorescence Imagery

To determine whether detection of fecal contamination on cantaloupes is possible using fluor mine whether detection of fecal contamination on cantaloupes is possible using fluor mine whether detection of fecal contamination on cantaloupes is possible using fluor mine whether detection of fecal contamination on cantaloupes is possible using fluor mine whether detection of fecal contamination on cantaloupes is possible using fluorescence imag- escence imag- escence imag- escence imag- escence imag- ing, hyperspectral images of cantaloupes artificially contaminated with a range of diluted bovine feces were acquired ing, hyperspectral images of cantaloupes artificially contaminated with a range of diluted bovine feces were acquired ing, hyperspectral images of cantaloupes artificially contaminated with a range of diluted bovine feces were acquired ing, hyperspectral images of cantaloupes artificially contaminated with a range of diluted bovine feces were acquired ing, hyperspectral images of cantaloupes artificially contaminated with a range of diluted bovine feces were acquired from 425 to 774 nm in responses to ultraviolet-A (320 to 400 nm) excitation. Evaluation of images at emission peak from 425 to 774 nm in responses to ultraviolet-A (320 to 400 nm) excitation. Evaluation of images at emission peak from 425 to 774 nm in responses to ultraviolet-A (320 to 400 nm) excitation. Evaluation of images at emission peak from 425 to 774 nm in responses to ultraviolet-A (320 to 400 nm) excitation. Evaluation of images at emission peak from 425 to 774 nm in responses to ultraviolet-A (320 to 400 nm) excitation. Evaluation of images at emission peak wavelengths indicated that 675 nm exhibited the greatest contrast between feces contaminated and untreated surface wavelengths indicated that 675 nm exhibited the greatest contrast between feces contaminated and untreated surface wavelengths indicated that 675 nm exhibited the greatest contrast between feces contaminated and untreated surface wavelengths indicated that 675 nm exhibited the greatest contrast between feces contaminated and untreated surface wavelengths indicated that 675 nm exhibited the greatest contrast between feces contaminated and untreated surface ar ar ar areas. Two-band r wo-band r wo-band r wo-band r wo-band ratios compar atios compar atios compar atios compar atios compared with the single-band images enhanced the contr ed with the single-band images enhanced the contr ed with the single-band images enhanced the contr ed with the single-band images enhanced the contr ed with the single-band images enhanced the contrast betw ast betw ast betw ast betw ast between the feces contaminated een the feces contaminated een the feces contaminated een the feces contaminated een the feces contaminated spots and untreated cantaloupe surfaces. The 595/655-nm, 655/520-nm, and 555/655-nm ratio images provided rela- spots and untreated cantaloupe surfaces. The 595/655-nm, 655/520-nm, and 555/655-nm ratio images provided rela- spots and untreated cantaloupe surfaces. The 595/655-nm, 655/520-nm, and 555/655-nm ratio images provided rela- spots and untreated cantaloupe surfaces. The 595/655-nm, 655/520-nm, and 555/655-nm ratio images provided rela- spots and untreated cantaloupe surfaces. The 595/655-nm, 655/520-nm, and 555/655-nm ratio images provided rela- tiv tiv tiv tively high detection r ely high detection r ely high detection r ely high detection r , both single band and ratio methods showed a number of false positives caused by such features as scarred tissues on cantaloupes. Principal compo- methods showed a number of false positives caused by such features as scarred tissues on cantaloupes. Principal compo- methods showed a number of false positives caused by such features as scarred tissues on cantaloupes. Principal compo- methods showed a number of false positives caused by such features as scarred tissues on cantaloupes. Principal compo- methods showed a number of false positives caused by such features as scarred tissues on cantaloupes. Principal compo- nent analysis (PCA) was performed using the entire hyperspectral images data; 2nd and 5th principal component (PC) nent analysis (PCA) was performed using the entire hyperspectral images data; 2nd and 5th principal component (PC) nent analysis (PCA) was performed using the entire hyperspectral images data; 2nd and 5th principal component (PC) nent analysis (PCA) was performed using the entire hyperspectral images data; 2nd and 5th principal component (PC) nent analysis (PCA) was performed using the entire hyperspectral images data; 2nd and 5th principal component (PC) image exhibited differential responses between feces spots and false positives. The combined use of the 2 PC images image exhibited differential responses between feces spots and false positives. The combined use of the 2 PC images image exhibited differential responses between feces spots and false positives. The combined use of the 2 PC images image exhibited differential responses between feces spots and false positives. The combined use of the 2 PC images image exhibited differential responses between feces spots and false positives. The combined use of the 2 PC images demonstrated the detection of feces spots (for example, minimum level of 16- demonstrated the detection of feces spots (for example, minimum level of 16- demonstrated the detection of feces spots (for example, minimum level of 16- demonstrated the detection of feces spots (for example, minimum level of 16- demonstrated the detection of feces spots (for example, minimum level of 16- g/mL dry fecal matter) with minimal false g/mL dry fecal matter) with minimal false g/mL dry fecal matter) with minimal false g/mL dry fecal matter) with minimal false g/mL dry fecal matter) with minimal false positives. Based on the PC weighing coefficients, the dominant wavelengths were 465, 487, 531, 607, 643, and 688 nm. positives. Based on the PC weighing coefficients, the dominant wavelengths were 465, 487, 531, 607, 643, and 688 nm. positives. Based on the PC weighing coefficients, the dominant wavelengths were 465, 487, 531, 607, 643, and 688 nm. positives. Based on the PC weighing coefficients, the dominant wavelengths were 465, 487, 531, 607, 643, and 688 nm. positives. Based on the PC weighing coefficients, the dominant wavelengths were 465, 487, 531, 607, 643, and 688 nm. This research demonstrated the potential of multispectral-based fluorescence imaging for online applications for detec- This research demonstrated the potential of multispectral-based fluorescence imaging for online applications for detec- This research demonstrated the potential of multispectral-based fluorescence imaging for online applications for detec- This research demonstrated the potential of multispectral-based fluorescence imaging for online applications for detec- This research demonstrated the potential of multispectral-based fluorescence imaging for online applications for detec- tion of fecal contamination on cantaloupes. tion of fecal contamination on cantaloupes. tion of fecal contamination on cantaloupes. tion of fecal contamination on cantaloupes. tion of fecal contamination on cantaloupes.