结合小波去噪的THz图像多尺度增强算法研究

针对返波管获得的连续THz透射图像对比度低且噪声大的特点,提出了一种结合小波去噪的多尺度图像增强算法.该算法先用图像金字塔变换对THz图像进行多尺度分解,然后采用指数变换在空域对获得的细节图像进行增强.为减小放大噪声的影响,在重构增强图像的过程中对每一分解层次的近似图像采用小波软阈值方法进行去噪,并对小波图像采用非线性...

Study of Multi-scale Enhancement Algorithm for THz Images Combining Wavelet Denoising

Due to low contrast and big noise in continuous-wave THz images obtained by backward-wave oscillator,a multi-scale image enhancement algorithm combining wavelet denoising is proposed.It performs multi-scale decomposition by building image pyramids first,and then enhances the detailed images by exponential transform in spatial domain.To remove the influences of enlarged noises,the wavelet soft-threshold method is adopted to denoise the approximation images in each level of the pyramid when rebuilding the enhanced image.Furthermore,nonlinear transform is also adopted for image enhancement in wavelet domain.Several experimental results demonstrate that,the proposed algorithm can remove noises efficiently,and the enhanced THz images have clear details and sharpened edges,which is useful for further image processing and recognition.