xmipp_transform_downsample (v3.0)
Usage
Downsample a micrograph. For volumes use xmipp_transform_geometry.
There are several downsampling methods. The most general and recommended is Fourier.
Fourier downsampling puts a window in Fourier space. This is the best downsampling that can be performed.
Altermatively, smoothing makes color dithering which is pretty good for visualization,
but it modifies the particle spectrum. Binning with a rectangle kernel modifies the
spectrum of the micrographs and is not recommended. You may see the effects of the different
downsampling schemes at
this article.
The downsampling factor (step) is the factor by which the micrograph will be reduced.
For instance, a downsampling by 2 will reduce the image size to one half. Using Fourier and smooth
you may use noninteger downsampling factors, and the image size will be reduced by 1/factor
See also
transform_geometry
Parameters

i, input <input_file>
 Input file: metadata, stack, volume or image.

mode <mode=overwrite>
 Metadata writing mode.
where <mode> can be:
 overwrite Replace the content of the file with the Metadata
 append Write the Metadata as a new block, removing the old one

label <image_label=image>
 Label to be used to read/write images.

o, output <output_file=>
 Output file: metadata, stack, volume or image.

oroot <root=>
 Rootname of output individual images. Output image format can be set adding extension after rootname as ":ext".

step <factor>
 Downsampling factor. factor=2 reduces the image size to one half. Fourier and smooth support noninteger downsampling factors. Rectangular binning must use integer factors.

method <mth=fourier>
 Method for making the downsampling
where <mth> can be:
 fourier <numThreads=1> Fourier supports noninteger downsampling factors
 rectangle This is simple binning in a square of size factor x factor
 smooth smooth and colordither
Examples and notes
xmipp_transform_downsample i micrograph.tif o downsampledMicrograph.tif step 2
User's comments
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