基于旋转、平移和尺度不变的平稳小波图像增强  

Image enhancement based on the stationary wavelet translation whit rotation,shift and scale invariance

作　　者：马志峰[1] 吴琼之[1] 杜娟[1] 

机构地区：[1]北京理工大学电子工程系,北京100081

出　　处：《光学技术》2009年第1期98-101,共4页Optical Technique

摘　　要：针对传统的离散正交小波变换对信号的起始位置比较敏感的特点,提出了具有旋转、平移和尺度不变的平稳小波变换,将图像变换到极坐标,采用方向能量函数确定图像主轴方位,并将图像主轴旋转到水平方向得到方向归一化的图像。然后通过对图像的重整和小波基的位移、伸缩、旋转,来消除位移和尺度的影响,得到具有旋转、平移和尺度不变的平稳小波变换。结合非线性增强算子以及Otsu自适应最优阈值估计方法,对图像进行增强。实验结果表明,提出的方法能够在增强图像的同时很好地保留图像的边缘信息,是一种有效的图像增强方法。Since traditional discrete orthonormal wavelet transform being more sensitive to the original position of signal, a stationary wavelet transform which possess the properties of rotation, shift and scale invariance is proposed. The image is transformed to polar coordinates, and confirming the principal axis orientation to adopt orientation energy function, then rotating the principal axis of image to the level orientation to gain the unifying image in the orientation. By reforming the image and rotation, shift and invariance to the wavelet bases, thus the influence of shift and scale is diminated, renormalized image projected on to the multi-resolution subspaces spanned by a set of shifted and dilated orthonormal wavelet basis function to get stationary translation and scale invariance. The non-linear gain operator enhances the image, combining Otsu adaptive optimization thresh- old estimation function. Experimental result show that the method can better reserve the image edge and enhance the image at the same time, and being a kind of valid method of the image enhancement.

关 键 词：应用光电子学 平稳小波 图像增强 阈值估计 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]