Centering : Utility for centering in 2D or 3D.

Usage in command line:

sp_center_2d3d.py input_stack_or_volume output_directory --mode=centering_mode --verbosity=verbosity_level --debug --threshsigma=threshold_sigma --applyshift stack_or_volume_to_be_centered --ndilation=number_of_dilations --nerosion=number_of_erosions --volradius=volume_radius --dimensions=number_of_dimensions --stem=output_volume_prefix --threshint=intermediate_threshold --pad=padding_factor

Left: uncentered binarized images, right: centered

The purpose of sp_center_2d3d.py is to:

: center a stack of 2D images, or
: center a 3D reconstruction

1. General usage:

sp_center_2d3d.py input_stack_or_volume output_directory

2. Center a stack of 2D images using an autocorrelation function

sp_center_2d3d.py input_stack output_directory --threshsigma=threshold_sigma 

Images will be thresholded in units of standard deviations above the mean. Check the output stkmask.hdf to see if the threshold is reasonable.

3. Centering a stack by rotating each image by 180 degrees and aligning to itself:

sp_center_2d3d.py input_stack output_directory --mode=rt180

4. Center a binarized volume using an autocorrelation function:

sp_center_2d3d.py input_binary_volume output_directory --applyshift=volume_to_be_centered

Generate the input binary volume using, for example, sp_mask.py. An adaptive mask is fine also; it will be thresholded. The mask will be centered, and those shifts will be applied to the volume to be shifted.

5. Center a binarized volume by finding a box that encloses it and centering that box:

sp_center_2d3d.py input_binary_volume output_directory --mode=boundingbox --applyshift=volume_to_be_centered

As above, the input binary mask will be centered, and those shifts will be applied to the volume to be centered.

6. Center a volume by alignment to a Gaussian blob:

sp_center_2d3d.py volume_to_be_centered output_directory --mode=blob --volradius=volume_radius

If your volume to be centered isn't round, try the radius in the smallest dimension.

input_stack_or_volume

Can be a 3D volume, possibly binarized, or a stack of 2D images

output_directory

Directory where outputs will be written. (default required string)

--mode

Centering mode: acf, rt180, boundingbox, or blob. (default acf)

--threshsigma

Binarization threshold in 2D acf mode, in units of standard deviation. (default 1.0)

--applyshift

In 3D acf or boundingbox mode, volume to which shifts will be applied. (default None)

--volradius

In blob mode, radius of the Gaussian blob, in voxels, to which the input map will be aligned. (default None)

--verbosity

Writes additional information to the screen (0..3). (default 1)

--debug

Writes additional outputs for debugging. (default False)

--dimensions

In case it is ambiguous whether the input is 2D or 3D (e.g., MRC format), enter 2 or 3. (default 3)

--threshint

In acf (2D or 3d) or boundingbox mode, threshold at which intermediates will be binarized. (default 0.1)

--pad

In acf mode (2D or 3D), factor by which images will be padded. (default 2)

--stem

In 3D acf mode, stem for output filenames. (default acf)

--ndilation

In 2D acf mode, number of dilations (see sp_mask.py for more information). (default 3)

Gray: uncentered map, violet: bounding box, melon: acf

--nerosion

In 2D acf mode, number of erosions (see sp_mask.py for more information). (default 0)

stkmask_centered.hdf

In 2D acf mode, binarized images after centering

stkavgs_centered.hdf

In 2D acf mode, input images after centering

stkcompare.hdf

In 2D acf mode, montage of mask, centered image, and masked image

stkcentered_rt180.hdf

In rt180 mode, input images after centering

vol_acf_centered.hdf

In 3D acf mode, volume of interest after centering

vol_blob_centered.hdf

In blob mode, volume of interest after centering

vol_box_centered.hdf

In boundingbox mode, volume of interest after centering

docshifts.txt

Shift parameters. Inputs will not be rotated.

Tapu Shaikh

Category 1:: APPLICATIONS

sphire/bin/sp_center_2d3d.py

Beta:: Under evaluation and testing. Please let us know if there are any bugs.

There are no known bugs so far.