Paper · 2003 · Crop Science

Quantifying Turfgrass Color Using Digital Image Analysis

Douglas E. Karcher; Michael D. Richardson

6
claims
9
verbatim quotes
57
citations
2
research areas
—
Not open access

Abstract

Color is a major component of the aesthetic quality of turf and often evaluated in field studies. Digital image analysis may be an improved, objective method to quantify turf color. Studies were conducted to determine if digital image analysis with SigmaScan software (SPSS, Chicago, IL) was capable of: (i) accurately determining the hue, saturation, and brightness (HSB) levels of Munsell Plant Tissue color chips, (ii) quantifying visual color differences among zoysiagrass (Zoysia japonica Steud.) and creeping bentgrass {Agrostis palustris Huds. [= A. stolonifera var. palustris (Huds.) Farw.]} plots receiving various N treatments, and (iii) quantifying genetic color differences among bermudagrass (Cynodon spp.) cultivars. Digital images of turf plots were analyzed with SigmaScan software to determine average HSB levels for each image. A dark green color index (DGCI) was created from HSB values for direct comparison with visual ratings. Digital image analysis accurately quantified the HSB levels (r2 = 0.99, 0.96, and 0.97, respectively) of Munsell color chips corresponding to turf colors. Significant HSB differences were present among N treatments in creeping bentgrass, while only significant hue differences existed in zoysiagrass. Significant hue and saturation differences were present among bermudagrass cultivars. There was strong agreement between DGCI values and visual ratings. The relative variances of the HSB and DGCI were significantly less than the variance associated with multiple raters. This evaluation technique may facilitate objective comparisons of turf color across researchers, locations, and years when images are collected under equal lighting conditions (i.e., the use of an artificial light source at night or in an enclosed system).

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Claims 6

Method / resourceobservedoriginal resultpositivemeasured

Claim · model-written summary

Digital image analysis accurately quantified hue, saturation and brightness of turf-color chips, with respective r2 values 0.99, 0.96 and 0.97.

Taxon
turfe0
Outcome
HSB levelse0
Value
0.99, 0.96, and 0.97e0

Verbatim

e0

“Digital image analysis accurately quantified the HSB levels (r2 = 0.99, 0.96, and 0.97, respectively) of Munsell color chips corresponding to turf colors”

✓ located verbatim in the source · abstract, characters 949–1102 · show in text ↑
Observationobservedoriginal resultsignificant (as stated)measured

Claim · model-written summary

Nitrogen treatments differed significantly in hue, saturation and brightness in creeping bentgrass.

Taxon
creeping bentgrassAgrostis stoloniferae0
Treatment
N treatmentse0
Outcome
HSB differencese0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Agrostis stolonifera
Agrostis stolonifera · TaxonAlfred · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

e0

“Significant HSB differences were present among N treatments in creeping bentgrass”

✓ located verbatim in the source · abstract, characters 1104–1185 · show in text ↑
Observationobservedoriginal resultsignificant (as stated)measured

Claim · model-written summary

Nitrogen treatments differed significantly only in hue in zoysiagrass.

Taxon
zoysiagrassZoysiae0
Treatment
N treatmentse1
Outcome
hue differencese0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Zoysia
Zoysia · Taxon · picture of the genus (one of its species)hey skinny from san diego, usa · CC BY 2.0 · Wikimedia Commons ↗

Verbatim

e0

“only significant hue differences existed in zoysiagrass”

✓ located verbatim in the source · abstract, characters 1193–1248 · show in text ↑
e1

“among N treatments in creeping bentgrass, while only significant hue differences existed in zoysiagrass”

✓ located verbatim in the source · abstract, characters 1145–1248 · show in text ↑
Observationobservedoriginal resultsignificant (as stated)measured

Claim · model-written summary

Bermudagrass cultivars differed significantly in hue and saturation.

Taxon
bermudagrassCynodon dactylone0
Material
cultivarse0
Outcome
hue and saturation differencese0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Cynodon dactylon
Cynodon dactylon · TaxonRobert Flogaus-Faust · CC BY 4.0 · Wikimedia Commons ↗

Verbatim

e0

“Significant hue and saturation differences were present among bermudagrass cultivars”

✓ located verbatim in the source · abstract, characters 1250–1334 · show in text ↑
Method / resourceobservedoriginal resultpositivemeasured

Claim · model-written summary

Dark green color index values strongly agreed with visual ratings.

Taxon
turfe1
Outcome
strong agreemente0
Comparator
visual ratingse0

Verbatim

e0

“There was strong agreement between DGCI values and visual ratings”

✓ located verbatim in the source · abstract, characters 1336–1401 · show in text ↑
e1

“quantify turf color”

✓ located verbatim in the source · abstract, characters 161–180 · show in text ↑
Method / resourceobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

HSB and dark green color index variance was significantly lower than variance from multiple raters.

Taxon
turfe1
Outcome
relative variances of the HSB and DGCIe0
Direction
significantly lesse0
Comparator
multiple raterse0

Verbatim

e0

“The relative variances of the HSB and DGCI were significantly less than the variance associated with multiple raters”

✓ located verbatim in the source · abstract, characters 1403–1519 · show in text ↑
e1

“quantify turf color”

✓ located verbatim in the source · abstract, characters 161–180 · show in text ↑