Non-local means

Gene

Deep learning

Image (mathematics)

Pattern recognition (psychology)

Artificial intelligence

Noise reduction

Chemistry

Image denoising

Computer science

Convolution (computer science)

Artificial neural network

Biochemistry

Robustness (evolution)

Convolutional neural network

Image processing

Pattern Recognition

While complex-valued transforms have been widely used in image processing and have their deep connections to biological vision systems, complex-valued convolutional neural networks (CNNs) have not seen their applications in image recovery. This paper aims at investigating the potentials of complex-valued CNNs for image denoising. A CNN is developed for image denoising with its key mathematical operations defined in the complex number field to exploit the merits of complex-valued operations, including the compactness of convolution given by the tensor product of 1D complex-valued filters, the nonlinear activation on phase, and the noise robustness of residual blocks. The experimental results show that, the proposed complex-valued denoising CNN performs competitively against existing state-of-the-art real-valued denoising CNNs, with better robustness to possible inconsistencies of noise models between training samples and test images. The results also suggest that complex-valued CNNs provide another promising deep-learning-based approach to image denoising and other image recovery tasks.

Image denoising using complex-valued deep CNN