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| VoCentering | |||||
| Process category | Brief description | Computational demand for typical tomography data (low, medium, high) | Comment(s) | Reference(s) | Common alternative process(es) |
|---|---|---|---|---|---|
| filter | To find an optimal value of CoR automatically. | High | Since the computational cost of this auto-centring process is high, it is normally applied to a small, representative sub-set of data (this can most conveniently be done using the preview parameter of this process). | Reliable method for calculating the center of rotation in parallel-beam tomography | VoCenteringIterative |
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| Item | Parameter name | Parameter format | Example(s) | Comment(s) | |
|---|---|---|---|---|---|
| Parameter value | Effect | ||||
| 1 | preview | Note that the preview parameter has a cumulative behaviour, i. e., if you specify VoCentering's preview parameter together with NxtomoLoader's preview parameter, then you will effectively be selecting a sub-set from NxtomoLoader's sub-set (rather than the entire dataset). | |||
| 2 | start_pixel | An initial estimate for the pixel coordinate of an optimal CoR. | |||
| 3 | search_area | If the value of the search_area parameter is set to the default interval of (-50, 50), then VoCentering will attempt to search for an optimal value of CoR in the (start_pixel - 50, start_pixel + 50) interval. For some datasets, this default range of search (100 pixel) may be not sufficiently large to include an optimal value of CoR, leading to subsequent sub-optimal reconstruction. Therefore, if the value of CoR determined by VoCentering is found to coincide with one of the search-interval limits (i. e. either start_pixel - 50 or start_pixel + 50), then this value of CoR may not necessarily be optimal, and one should re-run VoCentering with a larger value of the search_area parameter to confirm this result. | |||
| 4 | in_datasets | ||||
| 5 | search_radius | ||||
| 6 | ratio | ||||
| 7 | out_datasets | ||||
| 8 | datasets_to_populate | ||||
| 9 | row_drop | ||||
| 10 | step | In pixel units. | |||
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