Changes between Version 22 and Version 23 of Tutorial/AdvancedParticleImagingVelocimetry2


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Timestamp:
Jan 15, 2015, 4:44:49 PM (6 years ago)
Author:
vaillant1p
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  • Tutorial/AdvancedParticleImagingVelocimetry2

    v22 v23  
    1010
    1111= Mask =
    12 Open the original image with uvmat, selecting the transform option 'phys'. Create a mask polygon by the menu bar command Projection object/mask_polygon. Set the option 'mask_outside' and introduce the coordinates of the four corners in '''Coord''' (like for geometry calib). Plot the polygon. Then create the corresponding mask by '''Tools/make mask'''. The default name is 'mask_1.png' in the subfolder Dalsa1.mask.
     12Open the original image with '''uvmat''', selecting the transform option 'phys'. Create a mask polygon by the menu bar command '''Projection object/mask_polygon'''. Set the option 'mask_outside' and introduce the coordinates of the four corners in '''Coord''' (like for geometry calib). Plot the polygon then create the corresponding mask by '''Tools/make mask'''. The default name is 'mask_1.png' in the subfolder Dalsa1.mask.
    1313
    1414= Sub_background =
    15 We observe parasitic light rays on the images which correspond to fixed features, leading possibly to spurious velocity vectors equal to 0. To eliminate those we use sub_bacground.
     15We observe parasitic light rays on the images which correspond to fixed features, leading possibly to spurious velocity vectors equal to 0. To eliminate those we use '''sub_bacground'''.
    1616Open the image with 'series' and select the program 'sub_background'. This function is not provided in the default menu, so you need to use the last menu option 'more...', and select the function in the sub-folder 'series/' of the package uvmat. This option is then preserved in the menu for later use.
    17 Then run sub_background over the whole index range in i and j, using the default parameters. Answer Yes to the question 'apply levels', which will conveniently rescale the image brightness after background removal.
     17Then run '''sub_background''' over the whole index range in i and j, using the default parameters. Answer Yes to the question 'apply levels', which will conveniently rescale the image brightness after background removal.
    1818
    1919= First PIV =
     
    2828= Making two masks =
    2929The parietal jet requires a very good resolution, particularly among x. To limitate PIV to this jet, let us create a specific mask.
    30 Open the previously created contour polygon contour_mask.xml in uvmat  by the menu bar '''!Tools/Projection object/browse...'''. Check the box '''edit''' (tag '''[!CheckEditObject]''') in the frame '''Object''' of uvmat (right hand side) to allow editing of the polygon. then replace the lower x bound 0 by 52. Then create the corresponding mask by '''Tools/make mask''', save it with name Dalsa1.mask/mask_plume.png. Similarly create a mask for the bulk Dalsa1.mask/mask_bulk.png, with bounds in x [0 55].
     30Open the previously created contour polygon contour_mask.xml in uvmat  by the menu bar '''!Tools/Projection object/browse...'''. Check the box '''edit''' (tag '''[!CheckEditObject]''') in the frame '''Object''' of uvmat (right hand side) to allow editing of the polygon then replace the lower x bound 0 by 52. Create the corresponding mask by '''Tools/make mask''', save it with name Dalsa1.mask/mask_plume.png. Similarly create a mask for the bulk Dalsa1.mask/mask_bulk.png, with bounds in x [0 55].
    3131 
    3232= PIV on the parietal plume =