python - Inserting/adjusting png into plot [matplotlib] -

i'm doing illustrations paper in python using matplotlib library. in illustration have lot of lines, polygons, circles etc. want insert .png image outside.

here's i'm trying far:

import matplotlib.pyplot plt import numpy np matplotlib.patches import polygon  fig, ax = plt.subplots()  plt.tick_params(axis='x', which='both', bottom='off', top='off', labelbottom='off') ax.axis('off')  # drawing circle ax.add_patch(                 plt.circle((0, 0), 0.5, color = 'black')             ) # drawing polygon ax.add_patch(         polygon(             [[0,0], [20, 15], [20, 40]],             closed=true, fill=false, lw=1)         ) # importing image im = plt.imread("frame.png") # defining image position/size rect = 0.5, 0.4, 0.4, 0.4 # should these values be? newax = fig.add_axes(rect, anchor='ne', zorder=1) newax.imshow(im) newax.axis('off')  ax.set_aspect(1) ax.set_xlim(0, 60) ax.set_ylim(0, 40) plt.show() 

so question is, how determine values rect = 0.5, 0.4, 0.4, 0.4? e.g., want lower left corner of .png @ point [20, 15] , want height 25.

this resulting image:

but want dummy frame adjusted polygon points, (this one's adjusted in photoshop):

p.s. here link frame.png experiment with.

can plot lines , picture on same axis? that, use extent key in plt.imshow()

import numpy np import matplotlib.pyplot plt matplotlib.patches import polygon   im='d:/frame.png' img=plt.imread(im) fig, ax = plt.subplots()  frame_height=25 x_start=20 y_start=15 ax.imshow(img,extent=[x_start,x_start+frame_height,y_start,y_start+frame_height])  ax.add_patch(         polygon(             [[0,0], [20, 15], [20, 40]],             closed=true, fill=false, lw=1)         ) ax.set_xlim(0, 60) ax.set_ylim(0, 40) plt.show()