function to select a rectangular region of interest of a pylab figure

selectRectangle.py

def selectRectangle(fig):
    pts = fig.ginput(2)
    pts = np.array(pts)
    pts.sort(axis=0)
    pts = np.round(pts).astype(int)
    return pts

"""
#example usage:
axROI.imshow(frames.mean(2),cmap='gray',origin='lower')
pylab.draw()
ROI = selectRectangle(figROI)
axROI.fill_between(ROI[:,0],ROI[0,1],ROI[1,1],alpha=.1,facecolor='b')
framesROISum = np.sum(np.sum(frames[ROI[0,1]:ROI[1,1],ROI[0,0]:ROI[1,0],:],axis=0),axis=0)
"""