One of the seed characteristics which seems to correlate with the vigor is the speed of growing. An experimental rig was built to measure this speed using image processing and evaluation technique. The system was able to take automatically pictures in regular intervals, to process them and to carry out the necessary calculations. The image taken from the seedings was scanned by horizontal lines from the bottom to the top. The R, G and B values for each pixel of each line were summarized and a curve was drawn of the sums. Each curve was then derived. A pair of peeks - one below and one above the central line show the vertical edges of a seedling stem. The results of examination are shown in seedling high versus time diagram. The slope of the curve - and so the speed of growing - changes during observation at all the three varieties.
"Seed vigor test based on image processing", Proc. SPIE 3543, Precision Agriculture and Biological Quality, (14 January 1999); doi: 10.1117/12.336881; https://doi.org/10.1117/12.336881