This paper proposes a data hiding scheme based on pixel-value-ordering and predication-error expansion. In a natural image, most neighboring pixels have similar pixel values, i.e. the difference between neighboring pixels is small. Based on the observation, we may predict a pixel’s value according its neighboring pixels. The proposed scheme divides an image into non-overlapping blocks each of w...

In Non-Local Means (NLM), each pixel is denoised by performing a weighted averaging of its neighboring pixels, where the weights are computed using image patches. We demonstrate that the denoising performance of NLM can be improved by pruning the neighboring pixels, namely, by rejecting neighboring pixels whose weights are below a certain threshold λ. While pruning can potentially reduce pixel ...

Introduction: The limited resolution of the imaging system causes partial volume effects (PVEs). These results in spreading of image counts to the neighboring pixels. This phenomenon is called spill-out effect. This study aimed at quantifying PVEs using ImageJ. Methods:Technetium-99m solution of concentration of 74 kBq/ml was filled into spheres A, B<...