2000 by the America DICOM cardiac standard became universally accepted throughout the world as the only method appropriate for exchange of digital angiographic images. More recently, the DICOM Standards Committee has adopted a high-resolution standard, defined as 1024 1024 pixel images with up to 12 bits (4096 levels) of gray scale per pixel. The large quantities of digital data required to rep...

Grayscale halftoning converts a continuous-tone image (e.g., 8 bits per pixel) to a lower resolution (e.g., 1 bit per pixel) for printing or display. Grayscale halftoning by error diffusion uses feedback to shape the quantization noise into high frequencies where the human visual system (HVS) is least sensitive. In color halftoning, the application of grayscale error-diffusion methods to the in...

A new quadtree-based lossy image compression algorithm is introduced. One new feature is that one pixel in each quadtree block is predictively encoded while the remaining pixels are linearly predicted from this one and from pixels of previous blocks. Another is that the criteria for subdividing a block involves the reproduction error in each pixel, as opposed to the error energy for the entire ...

The Recursive Optimal per-Pixel Estimate (ROPE) algorithm allows the encoder to estimate the pixel-bypixel expected distortion of the decoded video sequence due to channel loss. The algorithm requires in input an estimate of the packet loss rate and the knowledge of the error concealment technique used at the decoder with no need to perform any comparison between original and decoded frames. Al...

Motion estimation (ME) algorithms supporting quarter-pixel accuracy have been recently introduced to retain detailed motion information for high quality of video in the state-of-the-art video compression standard of H.264/AVC. Conventional sub-pixel ME algorithms in the spatial domain are faced with a common problem of computational complexity because of embedded interpolation schemes. This pap...

A new proposed scheme is presented for digital image steganography which is a kind of spatial domain technique, works with the orderly replacement of the pixel components with the text data that is to be embedded . Proposed work is concentrated on 8 bits of a pixel (8 bits of Red or Green or blue component of a pixel in a 24 bit image), resulting better image quality. The proposed scheme shows ...

The pixel-value differencing (PVD) steganography can embed a large amount of secret bits into a still image with high imperceptibility as it makes use of the characteristics of human vision sensitivity. However, a loophole exists in the PVD method. Unusual steps in the histogram of pixel differences reveal the presence of a secret message. An analyst can even estimate the length of hidden bits ...

A pixel-based motion compensation (MC) technique where a motion vector is determined at every pixel is investigated. Image sequence compression using the present MC technique will require less bits for prediction error than that using conventional block-based MC techniques. One of the main problem of pixel-based MC is how to save the number of bits for the motion vectors. For this problem, some...

We introduce a rigorous mathematical theory for the analysis of local histograms, and study how they interact with textures that can be modeled as occlusions of simpler components. We first show how local histograms can be computed as a system of convolutions and discuss some basic local histogram properties. We then introduce a probabilistic, occlusion-based model for textures and formally dem...

In this paper we present an algorithm capable of rendering a displacement mapped triangle mesh interactively on latest GPUs. The algorithm uses only pixel shaders and does not rely on adaptively adding geometry. All sampling of the displacement map takes place in the pixel shader and bior trilinear filtering can be applied to it, and at the same time as the calculations are done per pixel in th...