python调用摄像头显示图像的实例_Python

python调用摄像头显示图像的实例

2021-03-25 09:46ShellCollector Python

今天小编就为大家分享一篇python调用摄像头显示图像的实例，具有很好的参考价值，希望对大家有所帮助。一起跟随小编过来看看吧

如下所示：

									import cv2

									import numpy as np

									bins = np.arange(256).reshape(256,1)

									def hist_curve(im):

									 h = np.zeros((300,256,3))

									 if len(im.shape) == 2:

									  color = [(255,255,255)]

									 elif im.shape[2] == 3:

									  color = [ (255,0,0),(0,255,0),(0,0,255) ]

									 for ch, col in enumerate(color):

									  hist_item = cv2.calcHist([im],[ch],None,[256],[0,256])

									  cv2.normalize(hist_item,hist_item,0,255,cv2.NORM_MINMAX)

									  hist=np.int32(np.around(hist_item))

									  pts = np.int32(np.column_stack((bins,hist)))

									  cv2.polylines(h,[pts],False,col)

									 y=np.flipud(h)

									 return y

									def hist_lines(im):

									 h = np.zeros((300,256,3))

									 if len(im.shape)!=2:

									  print "hist_lines applicable only for grayscale images"

									  #print "so converting image to grayscale for representation"

									  im = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)

									 hist_item = cv2.calcHist([im],[0],None,[256],[0,256])

									 cv2.normalize(hist_item,hist_item,0,255,cv2.NORM_MINMAX)

									 hist=np.int32(np.around(hist_item))

									 for x,y in enumerate(hist):

									  cv2.line(h,(x,0),(x,y),(255,255,255))

									 y = np.flipud(h)

									 return y

									if __name__ == '__main__':

									 import sys

									 if len(sys.argv)>1:

									  im = cv2.imread(sys.argv[1])

									 else :

									  im = cv2.imread('../cpp/lena.jpg')

									  print "usage : python hist.py <image_file>"

									 gray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)

									 print ''' Histogram plotting \n

									 Keymap :\n

									 a - show histogram for color image in curve mode \n

									 b - show histogram in bin mode \n

									 c - show equalized histogram (always in bin mode) \n

									 d - show histogram for color image in curve mode \n

									 e - show histogram for a normalized image in curve mode \n

									 Esc - exit \n

									 '''

									 cv2.imshow('image',im)

									 while True:

									  k = cv2.waitKey(0)&0xFF

									  if k == ord('a'):

									   curve = hist_curve(im)

									   cv2.imshow('histogram',curve)

									   cv2.imshow('image',im)

									   print 'a'

									  elif k == ord('b'):

									   print 'b'

									   lines = hist_lines(im)

									   cv2.imshow('histogram',lines)

									   cv2.imshow('image',gray)

									  elif k == ord('c'):

									   print 'c'

									   equ = cv2.equalizeHist(gray)

									   lines = hist_lines(equ)

									   cv2.imshow('histogram',lines)

									   cv2.imshow('image',equ)

									  elif k == ord('d'):

									   print 'd'

									   curve = hist_curve(gray)

									   cv2.imshow('histogram',curve)

									   cv2.imshow('image',gray)

									  elif k == ord('e'):

									   print 'e'

									   norm = cv2.normalize(gray,alpha = 0,beta = 255,norm_type = cv2.NORM_MINMAX)

									   lines = hist_lines(norm)

									   cv2.imshow('histogram',lines)

									   cv2.imshow('image',norm)

									  elif k == 27:

									   print 'ESC'

									   cv2.destroyAllWindows()

									   break

									 cv2.destroyAllWindows()