python - tuple error while cropping -

i crop image using command.

def imgcrop(im):         box = (0, 150, 640, 200)         region = im.crop(box)         region.save('crop.jpg')         return region 

then error come out this

attributeerror: 'tuple' object has no attribute 'crop' 

and im refering http://effbot.org/imagingbook/image.htm, method correct. please advise.

here full program, please advise

import cv2 cv2 import * pil import image  import rpi.gpio gpio import time im = 0  gpio.setwarnings(false)  gpio.setmode(gpio.bcm)  gpio.setup(27, gpio.out)        #input 1 gpio.setup(22, gpio.out)        #input 2 gpio.setup(9, gpio.out)         #input 3 gpio.setup(10, gpio.out)        #input 4 gpio.setup(7, gpio.out)         #enable 1 gpio.setup(8, gpio.out)         #enable 2  gpio.setup(15, gpio.in)         #turn right gpio.setup(18, gpio.in)         #turn left gpio.setup(23, gpio.in)         #backward gpio.setup(24, gpio.in)         #forward  p = gpio.pwm(7,50) q = gpio.pwm(8,50) p.start(0) q.start(0)  def forward():     p.changedutycycle(100)       q.changedutycycle(100)     gpio.output(27, gpio.high)      #input 1 low     gpio.output(22, gpio.low)       #input 2 high     gpio.output(9, gpio.high)       #input 1 low     gpio.output(10, gpio.low)       #input 2 high  def backward():     p.changedutycycle(100)       q.changedutycycle(100)     gpio.output(27, gpio.low)       #input 1 low     gpio.output(22, gpio.high)      #input 2 high     gpio.output(9, gpio.low)        #input 1 low     gpio.output(10, gpio.high)      #input 2 high  def left():     p.changedutycycle(100)       q.changedutycycle(100)     gpio.output(27, gpio.low)       #input 1 low     gpio.output(22, gpio.high)      #input 2 high     gpio.output(9, gpio.high)       #input 1 low     gpio.output(10, gpio.low)  def right():     p.changedutycycle(100)       q.changedutycycle(100)     gpio.output(27, gpio.high)      #input 1 low     gpio.output(22, gpio.low)       #input 2 high     gpio.output(9, gpio.low)        #input 1 low     gpio.output(10, gpio.high)  def stop():     p.changedutycycle(100)       q.changedutycycle(100)     gpio.output(27, gpio.low)       #input 1 low     gpio.output(22, gpio.low)       #input 2 high     gpio.output(9, gpio.low)        #input 1 low     gpio.output(10, gpio.low)  def imgcrop(im):         box = (0, 150, 640, 200)         region = im.crop(box)         region.save('crop.jpg')     return region  def imgthres(im):         gray = im.convert('l')         bw = gray.point(lambda x: 0 if x<50 else 255, '1')         bw.save("bw.jpg")     return bw  def find_centroid(im, rez):         width, height = im.size         xx, yy, count = 0, 0, 0         x in xrange(0, width, rez):             y in xrange(0, height, rez):                     if im.getpixel((x, y)) == 255:                         xx += x                         yy += y                         count += 1         return xx/count, yy/count  def camera ():     cam = videocapture(0)   # 0 -> index of camera     img = cam.read()     cimg = imgcrop(img)     timg = imgthres(cimg)     print find_centroid(timg, 1)  def robo_direct():         cen = find_centroid(timg, 1)         diff = cen[0] - 320         if diff > 10:         right()             print 'right'         if diff < -10:         left()             print 'left'         else:         forward()             print 'straight'    ####---------------------------------------------------------------------------------####  forward() while true:     camera ()     robo_direct() 

videocapture.read doesn't return image. listed in documentation, returns retval, image tuple. dunno retval is, that's problem.

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im tuple. tuples don't have crop method. if im isn't supposed tuple, @ function called , figure out why it's being passed tuple.

also, have mixed tabs , spaces indentation. may or may not causing problems right now, it's guaranteed headache @ point. switch tabs or spaces; pep 8 recommends spaces.