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Version 8.1 by wirtenss on 2022-11-14 15:30
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1 = {{id name="03aReconstructionwithRecoGUI-LoadingData"/}}Loading Data
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4 **TXM DATA**
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6 Go to "Load' tab and select year, enter your beamtime ID (e.g. 11001234) and press "enter" on keyboard.
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8 Now, the list of your scans will be shown below under "folder". Below folders, there are darks with different exposure times.
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10 Select the scan you want to reconstruct and choose the corresponding dark images.
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12 If you recorded your data after 2019, you can directly continue by clicking the "Load" button. This will read all data needed for reconstruction.
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14 Loading the data can take some time (usually several minutes). The GUI will be blocked during this time.
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16 Continue with next step, "Preparation".
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20 **HOLOTOMO DATA**
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22 Hint: you have to perform the phase reconstruction of your projections first!
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24 Go to "Load" tab. Click on "Load normalized data" at the bottom of the page and select your phase reconstruced projections.
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26 The common path is: ///asap3/petra3/gpfs/p05/YEAR/data/BEAMTIMEID/processed/SCANNAME/reco_~#~#//
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28 You do not need to load any additional dark images.
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30 Skip "Normalize, Minus Log, Rotate" in the Preperation Tab. The optional steps are still optional. (see below)
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32 In principle, you can directly proceed to the third tab "Reconstruction". 
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36 = {{id name="03aReconstructionwithRecoGUI-Preparationofdataforreconstruction"/}}Preparation of data for reconstruction =
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38 (Can be skipped for Holotomography)
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40 Go to "Prep" tab.
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42 The following is usually required for reconstruction:
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44 Click "Normalize" button. This will take several minutes.
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46 Click "Minus Log" button.
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48 Click "Rotate" button.
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52 The following steps are **optional:**
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54 **Cropping:** If your samples are significantly (% style="color: rgb(0,51,102);" %)__smaller__(%%) than the field of view, you can crop the data to reduce computation time and storage. Draw a rectangle around your sample by keeping the left mouse button pressed. Check that your sample stays inside that rectangle at all angles. If you are happy, press the "crop" button to crop your data.
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56 **Binning:** You can bin your data before reconstruction. Since the detector has a point spread function of 2-3 pixels, it is save to bin by a factor of 2 without loosing spatial resolution. This reduces computation time and storage space needed.
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58 **Padding:** If your samples are significantly __larger__ than the field of view, you can pad your data to prevent artifacts at the outer field of view. Example: 100
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60 **Filter Projections before reconstruction:** You can filter the data before reconstruction. This reduces the noise, but also can induce blurring in the data. Only recommended for very noisy data. Filtering after reconstruction is usually better.
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64 **Linogram alignment:** Linogram alignment if sample moved. Ask your local contact if this is necessary.
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68 **Save current stack.** Writes the normalized projections to your beamtime folder.
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72 = {{id name="03aReconstructionwithRecoGUI-Reconstruction"/}}Reconstruction =
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76 **Finding the correct center of rotation. **
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78 First, you have to find the correct center of rotation. For this, a single slice is reconstructed with different centers of rotation
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80 **~1. Rot center: **Defines the rotation center in pixel coordinates. For the start, enter half of your image size (1024 for unbinned data, 512 for data with binning 2.)
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82 **2. Delta: **Range of pixels around the in step 1 given rot center for which the test slice is reconstructed. Good starting value is 50. For fine rot center, choose 10. 
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84 **3. Stepsize:** Stepsize beween the different rotation centers. Good start value is 5 and 1 for fine rot center. (for example [ ... , 507, 512, 517, ... ] for a stepsize of 5)
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86 **4. Slice:** Defines the pixel row which is used to reconstruct the test slice. Tip: Choose a region where you expect to see distinctive structures. (You can also check different slices for checking the rotation center.)
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88 **5. Check rotation center: **Click on the "Check rotation center" button.** **In the preview window move the slider around until you find the positions with the least artifacts. Remember the position number and check the Spyder Console to get the new rot center coordinates in pixel.
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90 [[image:attach:image2022-11-14_14-4-49.png||thumbnail="true" height="250"]]
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92 in blue the coordinate of the center of rotation; in yellow the position number of the preview slider
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94 **6. Update and Repeat:** Replace the Rot Center (step 1) with the new found coordinate, lower the Delta (step 2) and Stepsize (step 3) and repeat the process until you are satisfied with the result.
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98 How does a good rotation center look like?
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132 The ghosting effect on the edges is due to sample movement during the scan.
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154 **Reconstruction Parameters. **
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156 When you found the correct rotation center, you can continue with the reconstruction.
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158 Enter the final roation center from the above step.
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160 You can select different reconstruction algorithms and filters. Standard is gridrec and shepp.
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162 You can also add ring removal (can take very long!!!!)
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164 Mask: If you like a circular mask around your data, check this box.
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166 before the final reconstruction, you can reconstruct a test slice to check your reconstruction parameters. Enter the slice number you want to reconstruct and press " Reconstruct slice".
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170 When you are happy with your result, press "Reconstruct full stack".
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172 You can check the data in ImageJ, and if you are not happy, you can also reconstruct with different parameters/ rotation centers.
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174 When you are finished with one scan, please press the "clear all" button! This saves the log data you see on the right, so you can later check what you did. The data are also removed from the memory.
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