Measure variance
SciPy measurement functions allow you to tailor measurements to specific sets of pixels:
- Specifying
labelsrestricts the mask to non-zero pixels. - Specifying
indexvalue(s) returns a measure for each label value.
For this exercise, calculate the intensity variance of vol with respect to different pixel sets. We have provided the 3D segmented image as labels: label 1 is the left ventricle and label 2 is a circular sample of tissue.
After printing the variances, select the true statement from the answers below.
This exercise is part of the course
Biomedical Image Analysis in Python
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Variance for all pixels
var_all = ndi.variance(vol, labels=None, index=None)
print('All pixels:', var_all)
# Variance for labeled pixels
var_labels = ndi.variance(____, _____, ____)
print('Labeled pixels:', ____)
# Variance for each object
var_objects = ____
print('Left ventricle:', var_objects[0])
print('Other tissue:', ____)