我试图绘制两个tiffs的高程差。出现以下错误消息：TypeError：图像数据的无效形状（1，2355，2676）。它引用im = ax. imshow.....行。我不太了解此问题或该怎么做。感谢您的帮助！

# import relevant moduls
from osgeo import gdal
import numpy as np
import matplotlib.pyplot as plt
from pygeotools.lib import iolib, warplib, geolib, timelib, malib

# Specify input files
dem_old = '../data/2007.tif'
dem_new = '../data/2018.tif'
# generate a list of the files
dem_fn_list = [dem_old, dem_new]

# combine dems with warplib and set to extent of intersection
ds_list = warplib.memwarp_multi_fn(dem_fn_list, extent='intersection', res='min', t_srs=dem_new)

# Load datasets to NumPy masked arrays
dem_old, dem_new = [iolib.ds_getma(i) for i in ds_list]

# Calculate elevation difference for each time period
dh_list = [dem_new - dem_old]

# plot elevation difference
print('Plotting DEM difference...')
plt.rcParams.update({'font.size': 15})
fig = plt.figure(figsize=(12, 12))
ax = fig.add_subplot(1,1,1)
im = ax.imshow(dh_list, origin='upper', interpolation='None', cmap='seismic_r', vmin = -40, vmax = 40)
# add colorbar
fig.colorbar(im)
# add title
plt.title("DSM elevation differences")
# disable xticks
plt.xticks([]) 
plt.yticks([])
# save figure
plt.savefig('glacier_change.png')
# show figure
plt.show()