Table 1:

Examples of taxonomic classification approaches

Approach	Object	Features/feature extractor	Classifier	Reference
Custom feature-based approach	Seed	Elliptic Fourier descriptor, Haralick's texture descriptor, morpho-colorimetric feature	LDA	[38, 39]
	Grain	Shape, color, texture features	MLP	[36]
			ANFIS	[37]
		SIFT, sparse coding	SVM	[40]
		Fourier descriptor, leaf shapes, vein structure		[55]
	Leaf	Pretrained CNN		[35]
		Ffirst		[56]
		Texture features	LWSRC	[57]
	Bark	Ffirst	SVM	[56]
	Tree	Reflectance, minimum noise fraction transformation, narrowband vegetation indices, airborne imaging spectroscopy features	SVM, RF	[58]
CNN-based approach	Grain			[59]
	Ear, spike, spikelet			[60]
	Leaf	CNN		[52, 53, 61, 62]
	Root			[62]
	Various organs			[63, 61, 56]

Ffirst: Fast Features Invariant to Rotation and Scale of Texture.