基于直方图均衡与小波变换的超声图像增强

针对超声图像对比度低、成像质量差的问题,提出了一种基于小波变换的直方图均衡算法,用于超声图像对比度增强,并使信息熵有很大提高。直方图均衡可以使图像灰度分布接近均匀,提高图像对比度,但图像的信息量会有一定程度的损失。本算法首先对图像作直方图均衡,然后通过对小波变换的一级或二级近似系数的非线性增强处理,使图像灰度分布更加均匀,损失的信息熵也得到很大提高。通过多幅的超声图像的实验结果证明,该算法效果明显,处理后的图像细节清晰可辨,边界信息也得到了保留。该算法对于超声图像临床视觉检查,以及图像目标识别、组织分割等都有很大好处。

Ultrasound image contrast enhancement based on histogram equalization and wavelet transformation

A new schemer for ultrasound image contrast enhancement using wavelet-based histogram equalization was presented to deal with the sonogram images with too low in contract and too dark for the naked eye. The histogram equalization can enhance the contrast by redistributing the gray levels, it has the drawback that it reduces the information in the processed image. This algorithm can enhance the image and compensate for the information loss during histogram equalization. Experimental results show that the wavelet-based enhancement algorithm can enhance the contrast and significantly increase the informational entropy of the image. This combination algorithm has the potential ability to improve clinical diagnosis.