METHOD OF IMPROVING THE CONTRAST OF IMAGES OBTAINED USING THE PULSED IMAGE-ADDITION ESPI TECHNIQUE

摘要

To improve the contrast of images obtained using the pulsed image-addition ESPI technique and relative to a mechanically stressed object, a preliminary measuring cycle is performed, with the object in the unstressed condition, to obtain a predetermined number of interference images (110-160) differing from one another by a controlled phase shift of a fraction of the pulses traveling along one of the branches of the interferometer; a mean luminous intensity value is calculated (170) from the interference images, is memorized (180), and is subtracted (220) from each of the interference images obtained during the actual measuring cycle to improve the contrast of the images.