Research On The Compression Of Image For RMB Crown Word Number

Crown word number is the identification of RMB, in order to manage RMB facilitatly, every one yuan only has a single corresponding crown word number.Character recognition is commonly used to record crown word number,but using the method may do less than one hundred percent accuracy if RMB is defiled.So this article adopts the way of recording the crown word number image to manage the crown word number.Image compression is essential to record crown word number image of RMB.To achieve a better compression performance, appropriate compression algorithm be selected for different types images.Wavelet theory is a new kind of image compression algorithm which is developed after Fourier transform and discrete cosine transform, the algorithm has the ability to describe non-stationary image signal and adapt to the characteristics of human visual. So wavelet theory is widely used and applicated in the filed of high-performance image compression.This paper first briefly introduced the basic theory knowledge about image compression coding, according to the characteristics of RMB crown word number image, a compression coding method is proposed which is based on the wavelet transform. And then the basic theory of wavelet transform is briefly introduced, including continuous wavelet transform theory, discrete wavelet transform theory, multi-resolution analysis theory, Mallat algorithm and decomposition and reconstruction of two-dimensional wavelet. On the basis of the above, the paper mainly studied embedded wavelet zerotree coding(EZW) for RMB crown word number, but through the simulation experiment, the disadvantages of EZW coding are found.So three kinds improved EZW encoding algorithm are adopted and analyzed to make up disadvantages of EZW coding, the three kinds improved EZW encoding algorithm are coding which combining EZW coding with run-length coding, SPIHT,SPECK.Through comparing simulation results of the three improved algorithm, SPECK coding algorithm is proved to be best. Finally, aiming at the deficiency of traditional wavelet transform, lifting wavelet transform is introduced. The improved SPECK coding, which is based on the lifting wavelet transform, is proposed, the simulation result of RMB crown word number image proves the algorithm is effective.