Image acquisition techniques for assessment of legume quality

•A detailed survey of image acquisition techniques and its components for testing of legumes.•Advantages and limitations of the techniques specific to their applicability are presented.•Future scope of work in the related area is also discussed.•This work is unique as no such survey exists for assessment of legume seed quality.

This paper reviews different image acquisition techniques that have been employed for quality evaluation of leguminous seeds and has relevance for engineers, food scientists and other agricultural researchers. The inspection and quality evaluation of food grains using machine vision can be achieved with greater speed, consistency and accuracy. Image acquisition is central to the success of any quality inspection system based on machine vision. Soybeans, peas, beans, lentils and chickpeas are the legumes, which form the staple food and hence have great ecological and economic importance. The image acquisition techniques that are reviewed in this paper are non-destructive in nature and are based on visible, infrared and other bands of the electromagnetic spectrum. These include techniques for external surface examination, measurement of moisture content, oil content, insect infestation detection and internal structure visualization. The advantages of machine-vision techniques over the conventional techniques based on manual methods for seed quality estimation are also discussed.