Region-of-interest based flower images retrieval

Flower image retrieval is a very important step for computer-aided plant species identification. We propose an efficient segmentation method based on color clustering and domain knowledge to extract flower regions from flower images. For flower retrieval, we use the color histogram of a flower region to characterize the color features of a flower and two shape-based sets of features, centroid-contour-distance (CCD) and angle code histogram (ACH), to characterize the shape features of a flower contour. Experimental results show that our flower region extraction approach based on color clustering and domain knowledge can achieve accurate flower regions. The retrieval results on a database of 885 flower images collected from 14 plant species show that our region-of-interest (ROI) based retrieval approach can perform better than the Swain method based on the global color histogram (Swain, M.J. and Ballard, D.H., Int. J. of Computer Vision, vol.7, no.1, p.11-32, 1991).