Make DDD movie stack¶

The following section comes from Appion Manual

Direct Detector Frame Processing¶

This section enables the user to create gain/dark corrected frame stack in mrc format from raw movie frames generated by direct detectors such as Direct Electron DE12 or DE20, Gatan K2 Summit. The equation used is found in this wiki on corrector

FEI Falcon II "raw" frames are already gain/dark corrected. The frame stack making process does not do that. However, it compiles the individual images as standard 32-bit float mrc image stack in this process and perform drift correction if so requested.

Gain/Dark Correction of movie frames¶

1. makeDDRawFrameStack: Frames obtained from DD, except Falcon, are not yet corrected for variation of pixel response. In the case of analog detection such as those performed by DE series and K2 Linear mode, they are also not dark corrected. This process performs these correction. The output is 32-bit mrc image stack. Also, it can be followed by frame alignment.
2. Catch up DD frame alignment: Using defergpu option in makeDDRawFrameStack when aligning, the gain/dark correction and alignment are broken up for more efficient use of gpu-capable host. In such a case, this process is launched.

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Notes, Comments, and Suggestions:¶

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^ Appion Processing

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Making Gain/Dark correction one image at a time without saving results to databases¶

Two scripts are attached here. They use Leginon infrastructure to locate references and do gain/dark correction and bad pixel/column/row correction. It, however, does not involve saving results to the leginon/appion databases. These are good for testing of add your own idea to it.

correctframes.py let you correct a range of raw frames in an image and output as mrc file.
correctstack.py let you correct each frame in the specified summed image and output at 2D image stack in mrc format.

type:

python correctframes.py

for the options

Do it yourself¶

If you want to do everything yourself, you can use the python script

getReferences.py

to find the location and filenames of the references and work on them yourself. The filenames are formatted to include various information. For example,

14aug12a_12221419_00_512x512_dark_0.mrc is a dark reference image at dimension of 512x512. It was taken during session 14aug12a at 22:14:19 and is for correction channel 0.

Beware that the fames are often in different orientation from the reference images in Leginon

To apply the correction, you need to use the equations found in Corrector

If there are no bad pixel/column/row on your camera that you included in your correction plan, you can feed the properly rotated/flipped references to the 2.0+ version of the drift correction program (motioncorr) by Xueming Li.

simple_correctstack.py can do the same as well using the library of Leginon/Appion, but not the database.