numpy image histogram plot
# tuple to select colors of each channel line
colors = ("red", "green", "blue")
channel_ids = (0, 1, 2)
# create the histogram plot, with three lines, one for
# each color
plt.xlim([0, 256])
for channel_id, c in zip(channel_ids, colors):
histogram, bin_edges = np.histogram(
image[:, :, channel_id], bins=256, range=(0, 256)
)
plt.plot(bin_edges[0:-1], histogram, color=c)
plt.xlabel("Color value")
plt.ylabel("Pixels")
plt.show()