Combining two series of perpendicular stripe scans¶
The Pro package of Pundit Vision enables merging series of stripe scans collected perpendicular to each other. Features in the final reconstructed volume are enhanced and better detailed than in the separated scans, as the final reconstructed volume benefits from the directional sensitivity of both collected measurement.
In this example two series of three stripe scans (as illustrated in the picture below) were collected with a 8-channel Pundit from Proceq SA, leading to 6 CSV rawdata files (one for data collected at 0° and one for data collected at 90°).
Import and convert raw data files¶
Open convert from pundit csv module
Note: The step between the images forming one stripe scan was 0.050 m (this value was set during the data collection in the Pundit’s App in the iPad and is recorded in the raw data file). The offset between each stripe scans of a same serie was 0.105 m (this value). This offset needs to be informed in the x-Distance box.
- Importing Serie 1 ((90° stripe scans)):
Axis of the future image (Yi- and Xi- axis) match that of the Pundit (Yp- and Yp- axis)
For each new stripe, the Pundit is moved upward, meaning that the X-offset is -0,105 m.
In addition, the origin of the pundi axis is rotated by 90°and offset by -0,21 m compared to the origin of the scanned area (defined by Yi- and Xi-axis)
Data are saved in a SDD file.
- Importing Serie 2((0° stripe scans)):
Axis of the future image (Yi- and Xi- axis) match that of the Pundit (Yp- and Yp- axis)
For each new stripe, the Pundit is moved toward the right, meaning that the X-offset is +0,105 m
Then same as for Serie 1, press ok, select a header, check settings and press ok.
Once both series of stripe scans have been converted the workdirectory should contain two sdd files (similar to below).
3D reconstruction in Inter_Saft module¶
Open inter_saft module and load the first sdd file
Process homogeneous SAFT then prepare 3D SAFT
Then again press start> sart homogeneous SAFT. Switch view from xz-view to yz-view
The previous operations need to be repeated for the second sdd file. The outcomes are two ghk files representing the 3D reconstructed volume.
Rotating axis of stripe scans collected at 90°¶
Open the module Edit Header. Load the rec3D.ghk file representing the data collected at 90° and inverse the x-axis and y-axis following the procedure below:
Save the edited header following the steps below:
Merging images in collect_measurements module¶
Once both files have been imported in Pundit Vision and the axis of the image collected at 90 degree rotated, then both images can be combined using the collect_measurements module.
Click Update Files, then the image of the first data file loaded appears. Then Click ‘Edit > File Table’. Then right click and ‘Add file’ to load the second data file (as shown below).
Click apply, following this, images from both files combined are displayed in the main collect measurement window:
Both images can be compared by setting different channel destination as follows:
At this stage one important step is to corrected the ‘Offset y’ of the image obtained from stripe scans collected at 90 degree. There is a 5 cm offset due to the abcissa origin of the perpendicular stripe scans set at the center of the pundit unit.
Finally, Both images can be merged into one by settings a single destination channel then saving the result, as described below:
End of the tutorial¶
After combining the file, you can call the browser on your new merged image directly from the collect_measurements module: click Tools>Call browser on result. Also, it is possible to create a video showing your new volume slice by slice.