in this paper, we introduce a multiresolution watermarking method for copyright protection of digital images. the method is based on the discrete wavelet transform. a noise type gaussian sequence is used as watermark. to embed the watermark robustly and imperceptibly, watermark components are added to the significant coefficients of each selected subband by considering the human visual system (...

Abstract: An Image is often corrupted by noise in its acquisition and transmission. Noise is any undesired information that contaminates an image. Speckle or Multiplicative noise, is a signal-dependent form of noise, whose magnitude is related to the value of the original pixel. This tends to reduce the image resolution and contrast. Denoising speckle is one of the most important process to inc...

Periodic noises are unwished and spurious signals that create repetitive pattern on images and decreased the visual quality. Firstly, this paper investigates various methods for reducing the effects of the periodic noise in digital images. Then an adaptive optimum notch filter is proposed. In the proposed method, the regions of noise frequencies are determined by analyzing the spectral of noisy...

conclusion vr reconstruction for both single-direction images and sushi using dti25 raw data provides excellent 3d displays of the peripheral nerves in the wrist region. sushi post-processing is a useful denoising tool because it automatically reduces the majority of isotropic object noise. results single-direction vr reconstruction clearly showed the nerves for both dti6 and dti25 but with obv...

Improving Statistical Image Reconstruction for Cardiac X-ray Computed Tomography by Jang Hwan Cho Chair: Jeffrey A. Fessler X-ray computed tomography (CT) is one of the most widely used imaging modalities for medical diagnosis. Recent advancements in CT scanner technology have led to increased use of CT in various applications. Unfortunately, these technological advances in CT imaging pose new ...