User_guide_draw_rois
This page shows example data available at: https://github.com/nifm-gin/Data_Test_MP3
First, one need to load an image. Then click on the ROI button on the left, above the images. Then select on the popup the wanted name of the ROI (If the name doesn't already exist, click on Other and type the new name).
Then the mouse cursor transforms itself into a cross cursor and allows to select the voxels that define the contour of the ROI, as shown on the following gif.
When either the last selected point join the first point of the ROI of if you right click, the ROI file is saved, the mouse cursor returns to normal, and the new ROI is available in the ROI list, and can immediately be displayed.
To draw a ROI on several slices, draw the first slice and repeat the operation (ROI button / select name / draw ROI contour) for each slice mindful of select the same ROI name for each slice.
Thanks to an algorithm based on active contour (Wang, Li, Lei He, Arabinda Mishra, et Chunming Li. « Active Contours Driven by Local Gaussian Distribution Fitting Energy ». Signal Processing, Special Section: Visual Information Analysis for Security, 89, nᵒ 12 (1st december 2009): 2435‑47. https://doi.org/10.1016/j.sigpro.2009.03.014.), one can draw semi-automatic ROIs.
When an image is displayed, click on the ROI_dyn button. Then define an ellipsis on the region you want to contour.
Release the mouse and observe the iterations of the algorithm contour the semi-automatic ROI.
Be careful, this algorithm works well to locate high contrast contours. Set different ellipsis as initialization can lead to better results.
To draw a ROI on several slices, draw the first slice and repeat the operation (ROI_dyn button / select name / draw ellipsis / observe) for each slice mindful of select the same ROI name for each slice.
First, display the ROI to modify. Then click on one of the ROI button (ROI or ROI_dyn), then select the name of the ROI to modify. A popup appears. Select either Union or Intersection. Then draw a new ROI.
If you chose Union, the resulting ROI will be the union of the initial and the new one.
If you chose Intersection, the resulting ROI will be the initial ROI minus the intersection of the initial and the new one.