MRE/Wave beta release General functions mrewave home data types reserved data input files output files clipboard resolution 1d plots 2d plots Wave inversion functions wave test data wave data wave parameters wave output wave unwrap wave filters wave lfe fftw faq known bugs |  |
resolution
Currently there are 3 options for modifying data resolutions: pixel replication is straightforward. linear interpolation: by default when doubling the resolution this option will want to increase the resolution by 1 less than 2X the resolution. The reason for this is seen in the diagram below. Increasing from 4 to 7 points allows the interpolated points to be equ-spaced between existing points. No matter what resolution is chosen, mrewave will begin interpolation centered at the 1st point and finish centered on the last point. So if you were to interpolate from 4 to 8 points the resulting grid would look like: Fourier interpolation: Since phase rolls in an image cause shifts in its transform, mrewave needs to know if data set is chopped. For real images always choose "smooth". For complex data the following example illustrates the choice between 'smooth' and 'chopped'. Consider selecting 'chopped' in two different cases. the original magnitude image
WRONG CHOICE | RIGHT CHOICE
The data is not chopped as seen in the phase image After the inverse ft, the data is shifted out to the edges of k space. Zero padding After the final forward ft a high frequency oscillation is seen in the image | The data is chopped as seen in the phase image After the inverse ft, the data is nicely centered in k space Zero padding After the final forward ft the same motion artifacts as seen in the original image are still present.

MRE/Wave beta release For future updates check: http://mayoresearch.mayo.edu/mayo/research/ehman_lab"