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Impact Of Human Visual Perception Of Color On Very Low Bit-Rate Image Coding, Sarah A. Rajala
Impact Of Human Visual Perception Of Color On Very Low Bit-Rate Image Coding, Sarah A. Rajala
Sarah A. Rajala
One of the keys to obtaining acceptable quality imagery/video encoded at very low bit rates is to transmit only that information which is critical to human perception. To successfully achieve this goal, one must not only understand the human visual system, but be able to utilize this information in the design of their codec. This paper will present an overview of the properties associated with color science and human visual perception, and how they could make an impact on very low bit-rate image coding.
Reducing Respiratory Artifacts In Chest Mr Images Through Hybrid Space Motion Tracking And Postprocessing, John N. Campbell, Wesley E. Snyder, Peter Santago Ii, Sarah A. Rajala, Craig A. Hamilton
Reducing Respiratory Artifacts In Chest Mr Images Through Hybrid Space Motion Tracking And Postprocessing, John N. Campbell, Wesley E. Snyder, Peter Santago Ii, Sarah A. Rajala, Craig A. Hamilton
Sarah A. Rajala
A new postprocessing method of correcting for respiratory motion induced artifacts in MRI is presented. The motion of the chest during respiration is modeled as a combination of translation and dilation. Displacements of the chest wall are tracked via a thin, MR-sensitive plate placed on the patient's chest during a scan. Scanning with phase encoding left/right (L/R) and frequency encoding anterior/posterior (A/P) causes the motion artifacts to be repeated in the L/R direction, thus not overlapping on the plate. By performing the inverse A/P Fourier transform, the resulting hybrid space data has A/P spatial data and L/R spatial frequency data, …
Use Of Extrapolation In Computing Color Look-Up Tables, Sarah A. Rajala, H. Joel Trussell, Atish P. Kakodkar
Use Of Extrapolation In Computing Color Look-Up Tables, Sarah A. Rajala, H. Joel Trussell, Atish P. Kakodkar
Sarah A. Rajala
Colorimetric reproduction requires calibrated color output devices. One way to characterize a color output device is with a 3D look-up table which maps the tristimulus values, t, to the control values, c of the output device. The functional form of the output device can be written in vector notation as t equals F(c). The purpose of calibration is to define an inverse mapping from tristimulus values to control values. Since the function F((DOT)) has no closed form, it is defined by interpolation from a table of values. Given a set of control values ]ci[ on a regular grid and the …