Image Histogrammes - Histogrammes cumulés - LUT- Egalisation d'histogrammes sous Python
Suite : • Image Filtrage : Lissage (Moyen - Ga... • Image Filtrage : Détection de contour... • Image Segmentation: Seuillage, Quanti...
Les programmes sont ici https://perso.usthb.dz/~akourgli/Trai...
-*- coding: utf-8 -*-
import cv2
import numpy as np
import matplotlib.pyplot as plt
plt.close('all');
Load the image
A = cv2.imread('p4.bmp')
L,C,D = np.shape(A)
A_rgb = cv2.cvtColor(A, cv2.COLOR_BGR2RGB)
plt.figure(1)
show 3 RGB bands
plt.subplot(341); plt.imshow(A_rgb[:,:,0],cmap='gray'); plt.title('Red')
plt.subplot(342); plt.imshow(A_rgb[:,:,1],cmap='gray'); plt.title('Green')
plt.subplot(343); plt.imshow(A_rgb[:,:,2],cmap='gray'); plt.title('Blue')
plt.subplot(344); plt.imshow(A_rgb); plt.title('RGB')
''' Histogrammes '''
hh=np.zeros(256)
for i in A_rgb[:,:,2]:
hh[i]+=1;
for i in range(3):
h = cv2.calcHist([A_rgb],[i],None,[256],[0,255])
plt.subplot(3,4,(i+5)), plt.plot(h);
plt.subplot(3,4,8), plt.plot(h);
h = np.cumsum(h)
plt.subplot(3,4,(i+9)), plt.plot(h/max(h));
''' Ealisation Histogrammes '''
A_HSV = cv2.cvtColor(A, cv2.COLOR_BGR2HSV)
A_HSV[:,:,2] = cv2.equalizeHist(A_HSV[:,:,2]);
A_EQ = cv2.cvtColor(A_HSV, cv2.COLOR_HSV2RGB)
plt.figure(2)
show 3 RGB bands
plt.subplot(341); plt.imshow(A_EQ[:,:,0],cmap='gray'); plt.title('Red')
plt.subplot(342); plt.imshow(A_EQ[:,:,1],cmap='gray'); plt.title('Green')
plt.subplot(343); plt.imshow(A_EQ[:,:,2],cmap='gray'); plt.title('Blue')
plt.subplot(344); plt.imshow(A_rgb); plt.title('RGB')
plt.subplot(3,4,8);plt.imshow(A_HSV[:,:,2],cmap='gray'); plt.title('V égalisé')
plt.subplot(3,4,12);plt.imshow(A_EQ); plt.title('RGB égalisé')
for i in range(3):
h = cv2.calcHist([A_EQ],[i],None,[256],[0,255])
plt.subplot(3,4,(i+5)), plt.stem(h);
h = np.cumsum(h)
plt.subplot(3,4,(i+9)), plt.plot(h/max(h));
A_rgb_EQ = np.empty((L,C,D),dtype=np.uint8);
for i in range(3):
A_rgb_EQ[:,:,i] = cv2.equalizeHist(A_rgb[:,:,i]);
plt.figure(3)
plt.subplot(221); plt.imshow(A_rgb); plt.title('RGB')
plt.subplot(222); plt.imshow(A_rgb_EQ); plt.title('RGB Egalisé')
plt.subplot(223); plt.imshow(A_rgb); plt.title('RGB')
plt.subplot(224);plt.imshow(A_EQ); plt.title('RGB égalisé par HSV')