Thermographic nondestructive evaluation (NDE): an algorithm for automatic defect extraction in infrared images

A practical algorithm for subsurface defect extraction (blobs) in infrared or in low spatial content images is proposed. It first locates potential defects by a spatial sorting of the pixels, placed in decreasing order, based on their brightness. Labeling of the pixels is based on the distance. Defect shape is grown by gradually decreasing the threshold until a sudden increase in the number of pixels agglomerates together or an image boundary is encountered. >