使用opencv中的findcontour提取表格

Question

我需要从几组工程图纸中提取表格。主要目标是检测和提取表格，我尝试使用find Contours，但它似乎没有为我输出正确的结果。原始图像：原始工程图预期输出：这是我想要的结果

代码

image = cv2.imread('01.png')
original = image.copy()
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray, (3,3), 0)
thresh = cv2.threshold(blur, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)[1]

cnts = cv2.findContours(thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
cnts = cnts[0] if len(cnts) == 2 else cnts[1]
for c in cnts:
peri = cv2.arcLength(c, True)
approx = cv2.approxPolyDP(c, 0.05 * peri, True)
if len(approx) == 4:
cv2.drawContours(thresh, [c], -1, (255,255,255), -1)

kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (40,10))
close = cv2.morphologyEx(thresh, cv2.MORPH_OPEN, kernel, iterations=2)

cnts = cv2.findContours(close, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
cnts = cnts[0] if len(cnts) == 2 else cnts[1]
for c in cnts:
peri = cv2.arcLength(c, True)
approx = cv2.approxPolyDP(c, 0.05 * peri, True)
x,y,w,h = cv2.boundingRect(approx)
aspect_ratio = w / float(h)
area = cv2.contourArea(approx)
if len(approx) == 4:
cv2.drawContours(image, [c], -1, (36,255,12), -1)
crop = original[y:y+h, x:x+w]
cv2.imwrite('image.png', image)
cv2.imwrite('ROI.png', crop)
cv2.waitKey()

Answer 1

如果所有图像的大小和形状都相同，排泄的部分总是在同一侧。你为什么要去findContours。我认为，你应该定义ROI坐标并裁剪零件。