normalizeとカラーヒストグラム

cv2.normalize()の使い方
RGBのカラーヒストグラムを例にnormalize()を使ってみる。

python 2.7
numpy 1.8.1
openCV 2.4.9
Windows 7 64bit

import cv2 import numpy as np img = cv2.imread('lena.jpg') channel = 3 calcRange = [0,256] lower = 0 upper = 100 hist = np.zeros([channel*upper,256],dtype=np.uint8) rows, cols= hist.shape hist = cv2.cvtColor(hist,cv2.COLOR_GRAY2BGR) for j in range(channel): chist = cv2.calcHist([img],[j], None, [256], calcRange) cv2.normalize(chist,chist,lower,upper,cv2.NORM_MINMAX) color = [0,0,0] color[j] = 255 y = rows - j*upper for i in range(0,256): v = chist[i] cv2.line(hist,(i,y),(i, y - v),color) cv2.imshow('result',hist) cv2.imshow('lena',img) cv2.waitKey() cv2.destroyAllWindows()

変数lower,upperが正規化するときの下限と上限。

2016/9/24 code修正 rangeに誤り