Calculate distance
A distance transformation calculates the distance from each pixel to a given point, usually the nearest background pixel. This allows you to determine which points in the object are more interior and which are closer to edges.
For this exercise, use the Euclidian distance transform on the left ventricle object in labels.
Este exercício faz parte do curso
Biomedical Image Analysis in Python
Instruções do exercício
- Create a mask of left ventricle pixels (Value of 1 in
labels). - Calculate the distance to background for each pixel using
ndi.distance_transform_edt(). Supply pixel dimensions to thesamplingargument. - Print out the maximum distance and its coordinates using
ndi.maximumandndi.maximum_position. - Overlay a slice of the distance map on the original image. This has been done for you.
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
# Calculate left ventricle distances
lv = np.where(____, 1, 0)
dists = ____
# Report on distances
print('Max distance (mm):', ____)
print('Max location:', ____)
# Plot overlay of distances
overlay = np.where(dists[5] > 0, dists[5], np.nan)
plt.imshow(overlay, cmap='hot')
format_and_render_plot()