# -*- coding: utf-8 -*- 

import cv2

#两个回调函数
def thresholdType(threshold_type):
 global THRESHOLD_TYPE 
 THRESHOLD_TYPE = threshold_type
 print threshold_TYPE, threshold_VALUE
 ret, dst = cv2.threshold(scr, THRESHOLD_VALUE, max_value, THRESHOLD_TYPE) 
 cv2.imshow(window_name,dst)

def thresholdValue(threshold_value):
 global THRESHOLD_VALUE
 THRESHOLD_VALUE = threshold_value
 print threshold_TYPE, threshold_VALUE
 ret, dst = cv2.threshold(scr, THRESHOLD_VALUE, max_value, THRESHOLD_TYPE) 
 cv2.imshow(window_name,dst)

#全局变量
"""
"Type: 
0: Binary 
1: Binary Inverted 
2: Truncate 
3: To Zero 
4: To Zero Inverted"
"""
THRESHOLD_VALUE = 0
THRESHOLD_TYPE = 3
max_value = 255
max_type = 4
max_BINARY_value = 255
window_name = "Threshold Demo"
trackbar_type = "Type"
trackbar_value = "Value"

#读入图片，模式为灰度图，创建窗口
scr = cv2.imread("G:\homework\SmallTarget.png",0)
cv2.namedWindow(window_name)

#创建滑动条
cv2.createTrackbar( trackbar_type, window_name,    threshold_type, max_type, thresholdType)
cv2.createTrackbar( trackbar_value, window_name,    threshold_value, max_value, thresholdValue )
#初始化
thresholdType(0)

if cv2.waitKey(0) == 27: 
 cv2.destroyAllWindows()

import threshold
> reload(threshold)
0 0
2 0
1 0
1 1
1 2
1 3
1 4
1 5
1 6
1 7
1 8
1 10
1 12
1 13
1 16
1 18