Question

我有一张图的图像。我对图像执行一些预处理功能，以提取图形线（有效）。但是，我然后尝试查找找到并保存为单独图像的图形线的轮廓。但是，当我这样做时，却没有得到想要的结果。

import cv2
import numpy as np
import matplotlib.pyplot as plt

img = cv2.imread("/Users/2020shatgiskessell/Desktop/graph_extracting/Test_Graphs/Graph2.jpg")
h,w = img.shape[:2]
mask = np.zeros((h,w), np.uint8)
mask2 = mask = np.zeros((h,w), np.uint8)

def find_contours(image):
    # Transform to gray colorspace and threshold the image
    gray = cv2.cvtColor(image,cv2.COLOR_BGR2GRAY)
    _, thresh = cv2.threshold(gray,0,255,cv2.THRESH_BINARY_INV+cv2.THRESH_OTSU)

    # erod then dialate image (for denoising)
    kernel = np.ones((2,2),np.uint8)
    opening = cv2.morphologyEx(thresh, cv2.MORPH_OPEN, kernel)

    #Find contours in order of hiarchy
    #CHAIN_APPROX_NONE gives all the points on the contour
    _, contours, hierarchy = cv2.findContours(opening,cv2.RETR_TREE,cv2.CHAIN_APPROX_NONE)
    return contours

#---------------------------------------------------------------
#CLEAN UP IMAGE AND JUST EXTRACT LINE
#get the biggest contour
cnt = max(find_contours(img), key=cv2.contourArea)
cv2.drawContours(mask, [cnt], 0, 255, -1)

# Perform a bitwise operation

res = cv2.bitwise_and(img, img, mask=mask)

# Threshold the image again
gray = cv2.cvtColor(res,cv2.COLOR_BGR2GRAY)
_, thresh = cv2.threshold(gray,0,255,cv2.THRESH_BINARY_INV+cv2.THRESH_OTSU)
# Find all non white pixels of image
non_zero = cv2.findNonZero(thresh)

# Transform all other pixels in non_white to white
for i in range(0, len(non_zero)):
    first_x = non_zero[i][0][0]
    first_y = non_zero[i][0][1]
    first = res[first_y, first_x]
    res[first_y, first_x] = 255

# Display the image
cv2.imwrite("extractedline.png", res)
#-------------------------------------------------------
#GET CONTOUR OF EXTRACTED LINE - NOT WORKING
i = 0
#Display contours
for contour in find_contours(res):
    #approximate the contour shape
    cv2.drawContours(mask2, [contour], 0, 255, -1)
    res2 = cv2.bitwise_and(res,res,mask=mask2)
    i = i+1
    print (i)

cv2.imshow('after', mask2)

OpenCV-生成的图像上的findContours不起作用

0 个答案: