如何使用Python操作摄像头
用过USB摄像头的都知道,你需要使用鼠标来操作它,比如截个图,录个像什么的,要点N次鼠标,对于我们那些不喜欢多次点击鼠标的人来说,这是一件很boring的事情,所以,本文将教你如何使用Python来操作摄像头。
这里,我们需要三个Python库: VideoCapture, PIL 和 pygame。使用这三个库你可以非常容易的编写一个摄像头程序。之所以使用pygame,其目的就是因为这个库可以处理视频帧(fps)。下面是代码:
from VideoCapture import Device import ImageDraw, sys, pygame, time from pygame.locals import * from PIL import ImageEnhance res = (640,480) pygame.init() cam = Device() cam.setResolution(res[0],res[1]) screen = pygame.display.set_mode((640,480)) pygame.display.set_caption('Webcam') pygame.font.init() font = pygame.font.SysFont("Courier",11) def disp(phrase,loc): s = font.render(phrase, True, (200,200,200)) sh = font.render(phrase, True, (50,50,50)) screen.blit(sh, (loc[0]+1,loc[1]+1)) screen.blit(s, loc) brightness = 1.0 contrast = 1.0 shots = 0 while 1: camshot = ImageEnhance.Brightness(cam.getImage()).enhance(brightness) camshot = ImageEnhance.Contrast(camshot).enhance(contrast) for event in pygame.event.get(): if event.type == pygame.QUIT: sys.exit() keyinput = pygame.key.get_pressed() if keyinput[K_1]: brightness -= .1 if keyinput[K_2]: brightness += .1 if keyinput[K_3]: contrast -= .1 if keyinput[K_4]: contrast += .1 if keyinput[K_q]: cam.displayCapturePinProperties() if keyinput[K_w]: cam.displayCaptureFilterProperties() if keyinput[K_s]: filename = str(time.time()) + ".jpg" cam.saveSnapshot(filename, quality=80, timestamp=0) shots += 1 camshot = pygame.image.frombuffer(camshot.tostring(), res, "RGB") screen.blit(camshot, (0,0)) disp("S:" + str(shots), (10,4)) disp("B:" + str(brightness), (10,16)) disp("C:" + str(contrast), (10,28)) pygame.display.flip()
这段代码中的一些要点的解释如下: