Research Of Compressing Carrier-Fringe Pattern Image

Three dimensional shape measurement is one of the hotspots in the field of information optics, and researchers give the much attention at it. At the moment we have develop a lot of measurements. Many of them need to project grating to the object. The grating stripes are inflected due to modulating by the object. We shoot the reflected images and after a series of computing, then we get the information of object shape. We call the reflected images as carrier-fringe pattern images. Usually we need to shoot a series of carrier -fringe pattern images which have large data. Especially for real-time measurement, we need to keep and send more data. It is necessary to use image compression technique in three dimensional shape measurement field because we need to shrink storage space and reduce cost of measurement equipment. In another case, pictures with BMP format have data redundancy. It means possible to use image compression technique in three dimensional shape measurement field.In this paper, we according to the characteristic of carrier-fringe pattern images to design compression arithmetic. Using Fourier transform profilometry and four-step phase-shifting method to demodulate the phase with compressed images. We also study phase error.In detail, we use JPEG to compress carrier-fringe pattern images. Using the compressed images to demodulate the phase and study the error, develop JPEG with a new two-value mask after discrete cosine transforming. Using wavelet transform to compress images and study the error. Then we design a new DCT two-value mask according to the frequency analysis. At last we discuss other image processing techniques.