Color recognition technology
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Color recognition technology has advanced to the point where it can accurately estimate vegetation cover, providing a new and powerful tool in ecological monitoring. I currently use the color recognition software VegMeasure, which was developed by Dr. Douglas Johnson at the Oregon State University. I am presently developing protocols that allow VegMeasure to accurately analyze both oblique and vertical photos.
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The parameters/algorithms within the program are saved and are used again to evaluate the change in percent cover of the post-treatment photos. For this methodology to work it requires that photos be taken:
a. at the same tilt angle b. during similar phenology time periods each year c. during times of the year when there is above average color contrast between the vegetation types that are being measured |
Using oblique photos and VegMeasure to estimate cover of woody vegetation
Pretreatment:
Pre-treatment photo:
oblique aerial photo of the wetland
project area with treated area
delineated for analysis in VegMeasure
Pre-treatment VegMeasure output photo:
-green is woody vegetation
-tan is herbaceous vegetation
-black is old burn piles and some shadows
Estimated percent cover of:
-woody vegetation is 61%
-herbaceous vegetation is 33%
-burn piles and shadows is 6 %
oblique aerial photo of the wetland
project area with treated area
delineated for analysis in VegMeasure
Pre-treatment VegMeasure output photo:
-green is woody vegetation
-tan is herbaceous vegetation
-black is old burn piles and some shadows
Estimated percent cover of:
-woody vegetation is 61%
-herbaceous vegetation is 33%
-burn piles and shadows is 6 %
Post-treatment:
Post-treatment photo:
oblique aerial photo of the wetland project area with treated area delineated
for analysis in VegMeasure
Post-treatment VegMeasure output photo:
-green is woody vegetation
-tan or reddish is herbaceous vegetation
-black is old burn piles and some shadows
Estimated percent cover of:
-woody vegetation is 16%
-herbaceous vegetation is 81%
-old burn piles and shadows is 3%
Overall woody vegetation was reduced by approximately 74%
oblique aerial photo of the wetland project area with treated area delineated
for analysis in VegMeasure
Post-treatment VegMeasure output photo:
-green is woody vegetation
-tan or reddish is herbaceous vegetation
-black is old burn piles and some shadows
Estimated percent cover of:
-woody vegetation is 16%
-herbaceous vegetation is 81%
-old burn piles and shadows is 3%
Overall woody vegetation was reduced by approximately 74%
Using VegMeasure to estimate area of burned vegetation
Estimated percent cover of area that was:
-unburned at Lupine meadows = 38%
-lightly burned = 45%
-heavily burned = 15%
-unclassified = 2%
In summary, approximately 60% of the west burn unit
showed some level of having been burned.
-unburned at Lupine meadows = 38%
-lightly burned = 45%
-heavily burned = 15%
-unclassified = 2%
In summary, approximately 60% of the west burn unit
showed some level of having been burned.
Using VegMeasure to survey for and estimate cover of weeds
The top photo shows where Scot’s broom
(a weed) is located within the landscape
at Bald Hill Park.
VegMeasure analysis of the area with Scot’s
broom. VegMeasure did a good job of
recognizing the yellow flowers of Scot’s
broom and the prairie (green) habitat.
Scot’s broom flower cover was 16% and
prairie cover was 84%. The color black
in the processed photos indicate unclassified
cover (species not analyzed in VegMeasure,
which was mostly trees).
(a weed) is located within the landscape
at Bald Hill Park.
VegMeasure analysis of the area with Scot’s
broom. VegMeasure did a good job of
recognizing the yellow flowers of Scot’s
broom and the prairie (green) habitat.
Scot’s broom flower cover was 16% and
prairie cover was 84%. The color black
in the processed photos indicate unclassified
cover (species not analyzed in VegMeasure,
which was mostly trees).
Using VegMeasure to estimate cover of weeds
VegMeasure analysis of an area (red box) with
oxeye daisy (a weed) present. VegMeasure did a good
job of recognizing and distinguishing the white
flowers of daisy and the prairie (green) habitat.
Oxeye daisy flower cover was 14% and prairie cover
was 72%. The color black in the processed photos
indicate unclassified cover, e.g. shadows,
shrubs/ trees (not in the photo), and areas
that fall between prairie and daisy.
oxeye daisy (a weed) present. VegMeasure did a good
job of recognizing and distinguishing the white
flowers of daisy and the prairie (green) habitat.
Oxeye daisy flower cover was 14% and prairie cover
was 72%. The color black in the processed photos
indicate unclassified cover, e.g. shadows,
shrubs/ trees (not in the photo), and areas
that fall between prairie and daisy.