The shape and colour of different plant parts have been used in the regulation of cultivar accessions and there is opportunity for increasing the effectiveness of these discriminators and widening their application. Images of three cultivars of Brussels sprouts. Each column is a separate cultivar. Although colour is often the most distinctive difference between cultivars and can readily be described verbally, it is more difficult to measure and record objectively. Outline shape, on the other hand requires a description based on where each part of an object lies.
Carrots can vary considerably in their outline shape.
This can be described by an automatic procedure which first segments the image into individual carrots, then finds the outline and automatically determines a number of landmark points on this outline. These can then be subjected to principal component analysis to define a number of independent shape scores. These shape scores have been found to contribute significantly to discrimination between cultivars. We have investigated the extent to which shape can be explored non-parametrically, using the whole outline. The approach first defines differences between outline shapes as the total area of non-overlap when the shapes have been translated and rotated to bring them into the closest possible alignment.