小波变换在数字图像处理中的应用是小波变换典型的应用之一。由信号分析中傅里叶变换的不足引出小波变换, 然后简单介绍了小波变换的定义和种类, 分析了小波变换的性质和Mallat 算法, 总结了小波变换在数字图像处理中的四种应用:基于小波变换的图像压缩、图像去噪、图像增强和图像融合, 分析了四种应用的过程及特点, 同时进行了相应的Matlab试验与仿真。试验结果表明, 小波变换在数字图像处理中的应用切实可行、简单方便、效果好、有很强的实用价值, 有较好的应用前景。-The applicatio n of wave let transform in digital imag e processing is one o f the ty pical applications of wavelet transform .The w avelet transform is introduced fo r the lack o f Fourier tr ansfo rm in the sig nal analysis , the definitio n and types of the wavelet transform ar e pro po sed briefly , and its proper ties and Mallat alg orithm a re analy zed .Fo ur kinds o f applicationsof wavelet transfo rm in dig ita l image pro ce ssing ar e summarized(imag e compr essio n, image denoising , image enhancement and image fusion based o n w avele t tr ansfo rm), the processe s and char acte ristics of this fo ur kinds of applicatio ns are analyzed,meanw hile the co r respo nding Ma tlab ex pe riment and simulatio n ar e made .Ex perimental results show that it is practical, simple , convenient a nd effective , and has a stro ng practical value and a g oo d applicatio n pro spects for the wavele t transform in digital image pro cessing .