Fig 1.
Location and plot layout of the two test fields.
The genotypes of the plots in field 1 were indicated in different colors.
Table 1.
Data collection summary.
Fig 2.
DEM: digital elevation model. MLESC: maximum likelihood estimation sample consensus. NDVI: normalized difference vegetation index.
Table 2.
Summary of the image processing time for generating ortho-mosaic and DEM in PhotoScan.
Dense cloud and DEM was not built for 8/28 dataset since the ortho-mosaic was used for flower detection.
Fig 3.
Accuracy of height measurements of the ground calibration targets by the imaging method.
A) The error in calculating ground calibration target heights before error correction. B) The error in calculating ground calibration target heights after error correction.
Fig 4.
Error of the calculated maximum plot height.
A) The absolute error in calculating maximum plot heights. B) The relative error in calculating maximum plot height.
Fig 5.
The error distribution for the maximum plot height.
Fig 6.
Correlation between calculated maximum plot heights and manually measured maximum plot heights using a linear model.
Fig 7.
Correlation between NDVI and canopy cover on different dates.
Fig 8.
A) Pixel values of four objects (flower, canopy, ground, and ground shade). B) The four regions of interest in the image.
Fig 9.
Example plots of the automatically detected flowers in the multispectral images (composited from the blue, red, and green band) and manually identified flowers in the color images.
In the multispectral images (top image in each panel), the magenta lines indicate detected flowers. In the color images (bottom image in each panel), the yellow circles indicate detected flowers and the yellow squares indicate undetected flowers in multispectral images. A) All the flowers in the color image were detected in the multispectral image. B) The flower inside the canopy was not detected in the multispectral image. C) Spots with high specular reflectance from the leaves were misclassified as flowers in multispectral images while the color images showed no flowers. D) Most of the flowers in the color image were detected in the multispectral image. Two partly hidden flowers and one flower inside the canopy were not detected in the multispectral image.
Table 3.
Comparison of the flower detection using multispectral images with the manual detection using color images.
Fig 10.
Histogram of the height for one plot over 42 days.
Blue and green areas indicate the ground and canopy, respectively. Blue and red lines respectively indicate the 85th and 100th percentile (maximum) of canopy heights.