函數adaptiveThreshold中的CV_8UC1（Error-215）

Question

在此代碼中，我們使用諸如cv2，NumPy和PIL等工具預處理Tesseract OCR的RGB圖像。當這個代碼在Python 2.7.13 Shell中執行時，我收到以下錯誤消息。

Traceback (most recent call last): File "C:\Automation\OCR\images\OCR_Preprocessing_ RGB.py", line 23, in <module> cv2.THRESH_BINARY,11,2) error: C:\build\master_winpack-bindings-win32-vc14-static\opencv\modules\imgproc\src\thresh.cpp:1446: error: (-215) src.type() == CV_8UC1 in function cv::adaptiveThreshold 

這裏是錯誤產生的代碼。我認爲問題可能出現在代碼行上。

import cv2 
import numpy as np 
from matplotlib import pyplot as plt 
from cycler import cycler 
from PIL import Image, ImageEnhance 

# Loads the image then enhances it 
image = Image.open('teleCapture.png') 
contrast = ImageEnhance.Contrast(image) 
img = contrast.enhance(2) 
img = np.asarray(img) 
r,g,b,a = cv2.split(img) // I know the issue is here, I have too many channels for an RGB image or I am merginf them wrong. 
contrast = cv2.merge([b,g,r]) //"Contrast" was used as a src during Thresholding, is this what it should be? 

# Adaptive Gaussian Thresholding //The problem may be within the thresholding, does this thresholding function only work using grayscale images? 
th1 = cv2.adaptiveThreshold(contrast,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C,\ 
     cv2.THRESH_BINARY,11,2) 
# Otsu's thresholding 
ret2,th2 = cv2.threshold(contrast,0,255,cv2.THRESH_BINARY+cv2.THRESH_OTSU) 
# Otsu's thresholding after Gaussian filtering 
blur = cv2.GaussianBlur(contrast,(5,5),0) 
ret3,th3 = cv2.threshold(blur,0,255,cv2.THRESH_BINARY+cv2.THRESH_OTSU) 

# writes enhanced and thresholded img 
cv2.imwrite('preprocessedTeleCapture.png', th2) 

Answer 1

閾值法需要1通道圖像作爲輸入，並且您給出3通道，這是錯誤消息中顯示的問題。