In order to get continuous and one-point-width of edge line, a method for noise-supprssion in accordance with rough
extent of image is presented. After getting the edge lineby way of wavelets transform, a suit of improvements for edge
line is established and adopted. Finally, a satisfied result is obtained with piece grain image segmented successfully.
Fourier Transform Profilometry and Phase Shifting are two important methods in 3-D measurement of body. Phase-shifting requires exact Phase-shifting sets, and more than an image collected, therefore its application is limited. Fourier Transform Profilometry required only an image, and calculated phase value of each point, measurement is higher degree of precision and wide range, its application is not limited. Wavelet Digital Filter and Fourier Transform Profilometry are combined, higher spectrum and direction components removed, kept useful components, raised dividing phase degree of precision, phase information of measured body resolved. This paper presents the analysis above the calculus and the results of simulated experiment.
In 3D projecting grating profilometry, we are often persecuted by some disgusted phenomenon of images, such as reflecting flare, overlapping of grating and other noise. All these can bring a bigger error in image processing. The intention of this paper is to propose some special filter and other methods of image processing. The technique we applied is based on peculiarity of projecting grating profilometry image, which has obvious directionality. We used the nonsymmetrical multi band-pass filters to reject the high frequency noise along the grating and other component except base frequency part. The result obtained from the processed image by multi band-pass filter is much better than that from primary image. The method is propitious to measure some smooth surfaces.
The shift step must be an accurate value in the traditional algorithm of phase-measuring profilometry technology, the result error is found in unequal step-shifting in which one or more step is not the accurate value. So the phase shifter is expensive to meet the high precision. In this paper, the software is made to give a chart of error phase in any unequal step phase-shifting, and a calibration algorithm is presented to give the correct phase based on this error-phase chart. With the help of computer emulator written by us, the calibration algorihtm based on checking proved to be correct. So the precise request of phase shifter is reduced greatly.
The surface profile is presented various, that forming cause of the specific trace is different. The specific trace is distributed as two types, from its criterion. First, the criterion of the specific trace is large, surpass a millimeter, is called grand specific trace; Second, the criterion is small, more or less the same length micron, is called micron specific trace. Using projection, contracting beam micrography, two-dimensions adusting image mode exchange, low-pass filter off noise, wavelet, and intelligent mode phase reconstruction, the surface profile of recognizing specific trace is given exactly and rapidly, that is a new optical image processing technology in recognition and diagnosis. This paper introduces the speciality above the technology and gave typical examples.
This paper described principle of some projection technologies, attached importance to some measurement technologies in engineering and measurement in complicated profile of fine-micro body. The optoelectronical system and the image processing system are supplied. The typical measurement result are obtained. It is proven that the projection technology is a composite technology, which has extensive applications in many ways.
In three-dimensional projecting grating profilometry, we are often persecuted by some disgusted phenomenon of images, such as reflecting flare, overlapping of grating and other noises. All these can bring a bigger error in image processing. The intention of this paper is to propose some new methods of image processing. The technique we applied is based on frequency domain digital image processing, morphology method and partial handling method. As the background disturbance can be eliminated by frequency domain filter, many image noises can be suppressed and the distinguishing feature of grating can be accentuated by morphology method with suitable structure element and partial handling method. Thereby, the result of the surface shape can be calculated much better than the conventional method. The results of experiment indicate that new methods have remarkable effects.
Speckle interferometry is an efficiency method to analyze vibration. In certain conditions, this technique has some outstanding, and not need strict shook-proof condition, compared with the holographic method for measuring vibration. Therefore, it is suitable for analysis vibration with a large amplitude. Real-time interferometry is a rapid and simple method for measuring vibration of a body, it gives speckle pattern containing amplitude distribution of body-surface. By means of time-averaged method, the speckle pattern is recorded in fourier transform plane, or vibration lines are seen directly with eye, so analyzed efficiently amplitude, phase, and model of vibration. This paper deduces the intensity distribution function with real-time method, and gives experimental proofs of vibration body--the vibration lines with different frequencies, the last, the conclusion.
In this paper, a geometrical moiré method for displaying directly isochromatics and isoclinics of a diametrically pressed circular disk is presented. It is demonstrated that by using two identical or different Wulff nets (or grids) not only the stress fields of a circular disk can be displayed, but the u-and v- displacemet fields can be also produced.