Image x, y coordinate of pixel from which spectrum was displayed?

Hello, is there a way to display the x/y coordinates of a pixel from which a spectrum was just displayed using imshow? When I double-click on a displayed image and a pixel spectrum is displayed in a new pop-up window, it would be great if the x/y coord was displayed so that I could then easily extract that spectrum from the cube using

spectrum1 = image.read_pixel(2225, 3801)

Now I have to use ENVI to get the pixel coordinate, or display the image in the normal backend using %matplotlib widget magic, with which x/y coords and band DN values are streamed when you move the mouse.

Thank you…

[pythonic2020]

Here is sample code to extract spectra from cube using Jupyter Notebook and new mouse handler from above:

import numpy as np
import matplotlib as mpl

# May need to install wxpython and pyopengl
mpl.use('WXAgg') # Must enable for spectral plots and 3-d cube, and call it before importing pyplot
import matplotlib.pyplot as plt

import spectral.io.envi as envi

# Open cube as SpyFile
cube1 = envi.open('envi_cube.hdr', image=envi_cube')

from spectral.graphics.spypylab import ImageViewMouseHandler, KeyParser
from spectral import settings

class MyMouseHandler(ImageViewMouseHandler):
    def handle_event(self, event): 
        '''Callback for click event in the image display. Will write coordinates
of clicked pixel in notebook cell. Written by tboggs.''' 
        if self.show_events: 
            print(event, ', key = %s' % event.key) 
        if event.inaxes is not self.view.axes: 
             return 
        (r, c) = (int(event.ydata + 0.5), int(event.xdata + 0.5)) 
        (nrows, ncols) = self.view._image_shape 
        if r < 0 or r >= nrows or c < 0 or c >= ncols: 
            return 
        kp = KeyParser(event.key) 
        if event.button == 1: 
            if event.dblclick and kp.key is None: 
                if self.view.source is not None:  
                    print("YOU CLICKED", (r, c)) 
                    if self.view.spectrum_plot_fig_id is None: 
                        f = plt.figure() 
                        self.view.spectrum_plot_fig_id = f.number 
                    try: 
                        f = plt.figure(self.view.spectrum_plot_fig_id) 
                    except: 
                        f = plt.figure() 
                        self.view.spectrum_plot_fig_id = f.number 
                    s = f.gca() 
                    settings.plotter.plot(self.view.source[r, c], 
                                          self.view.source) 
                    s.xaxis.axes.relim() 
                    s.xaxis.axes.autoscale(True) 
                    f.canvas.draw()

from spectral.graphics.spypylab import imshow 

# Must use full image to get accurate image coordinates for spectra. Don't view a subset!

view = imshow(data=cube1, bands=(76, 83, 92), origin='upper', stretch=(0.08, 0.98),
              source=cube1, title='Cube - Bands 76-83-92/RGB', figsize=(6, 6))

handler = MyMouseHandler(view)
handler.connect()

# Use magnify tool in pop-up window to zoom to area of interest.  Then double-click in the window to display spectrum.

# Extract spectrum from pixel selected above.  Insert your own coordinates.  Creates 1-d numpy array.
spectrum1 = cube1.read_pixel(2225, 3801) 

[pythonic2020]

It worked!!! YOU CLICKED line displayed in notebook!!! Perfect. Great job. Many thanks.