Automatic Ultrasonic Inspection for Surface Flaws of Square Billets

Automatic Inspection of Aircraft Components Using Thermographic and Ultrasonic Techniques

Ultrasonic Inspection of Sub-Surface Defects In Aluminium Die- Castings

Non-destructive testing using ultrasonic measurement is used to ensure the quality of the die-casting products. The quality of a casting depends on the presence of discontinuities such as porosity and on the final metallurgical structure. Discontinuities occurring in the sub-surface of the cast structure mostly have irregular surfaces which scatter the ultrasound waves and make ultrasonic testi...

Ultrasonic inspection of rough surface aluminium die castings

The condition of the surface through which a sound beam enters a material is an important factor in ultrasonic non-destructive testing(1). Detection of discontinuities such as cracks, voids and porosities in castings is greatly affected by the extent of roughness. Increased roughness reduces the transmitted energy of the sound beam and this, in turn, reduces the amplitude of the received signal...

Automatic surface inspection using wavelet reconstruction

In automatic surface inspection, one has to solve the problem of detecting small surface defects which locally break the homogeneity of a texture pattern. Textures are generally classified into two major types, structural and statistical [1]. Structural textures are those that are composed of repetitions of some basic texture primitive, such as directional lines, with a deterministic rule of di...

Automatic surface inspection for directional textures using nonnegative matrix factorization

A global image restoration scheme using nonnegative matrix factorization (NMF) is proposed in this paper. This NMF-based image restoration scheme can be used for inspecting the defects in directional texture surfaces automatically. Decomposing the gray level of image pixels into an ensemble of row vectors, we first reduce the data set from original data space into a lowerdimensional NMF space. ...