Image Measurement Research Based Multi-scale Edge Detection

Along with the rapid development of digital image gathering and processing technology, image has become an important way for people to gain information, and it has also become an important content of the image processing to make the correlation evaluation using the image information to the product geometry information. Moreover, image measurement technology is a new technology in measurement domain in recent years. It takes optics as foundation, combining photo-electronics, computer technology, laser technology, and digital image processing technology as a body, composing light, machine, electricity, calculation to the resultant measurement system. The so-called image measurement is the measuring technique that image is treated as detection and transmission information method or carrier which to be used when measuring the objects measured.Image measurement based on image processing is a very new and advanced measuring technique, at present, it already widely application in geometry, aviation and remote sensing measurement, precise complex components micro size measurement and outward appearance examination, as well as light wave interference figure, stress strain field condition distribution technology with image related areas. To image measurement, if we want to enhance the system precision, we may enhance the hardware facility and so on. But it has huge limit to improvement hardware facility, while the method using software algorithm is simply, effective and so on. Therefore, research of image measurement software algorithm has practical significance verymuch.Principle of image measurement system is to measure geometry parameter of the object through processing the edges of image. So image edge distilling is the measurement foundation and key in image measurement system. This paper accords to distill the image edge that require few noise, edge continuity strong also orientation accuracy high characteristic in image measurement. At the same time according to wavelet analysis some characteristics, which developed in recent years: Like the resolution in wavelet analysis adjusts in the time zone along with the frequency size. Low frequency is careless. High frequency is precise. The signal and noise are separated by a certain way;Wavelet transform especially is sensitive to pair strange characteristic, which make it to adapt to detect the image edge and detail. According to above these characteristics, wavelet analysis is used in image measurement to carry on edge detection. At the same time according to Mallat multi-scale thought, using the edge by the great scale which can control noise instructs the edge by the small scale which can locate accurately, finally we obtain the noise to be few, continuous, pinpoint image edge of image measured.Research goal of the paper is geometry quantity measurement of some images. Regarding the hardware part of image measurement system is not the key which this paper studies. Emphases of this paper are how to use the wavelet analysis theory carries on image measurement to images gathered.