删除附加到图像边框的元素

Question

我正在使用 OpenCV 通过图像处理检测胸部 X 光片中的肺炎，因此我需要移除图像边界的附加区域以仅获取肺部，任何人都可以帮助我在 python?

这张图片解释了我想要的东西this image after applying this methods: resized, Histogram Equalization, otsu Thresholded and inverse binary Thresholded, morphological processes(opening then closing)

这是原始图像Original Image

Answer 1

您可以尝试使用以边框为标记的形态重建。这是来自 Matlab 或 Octave 的函数 imclearborder 的模拟。

import cv2
import numpy as np
img = cv2.imread('5R0Zs.jpg')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
thresh = cv2.threshold(gray, 40, 255, cv2.THRESH_BINARY)[1]
kernel = np.ones((7,7),np.uint8)
kernel2 = np.ones((3,3),np.uint8)
marker = thresh.copy()
marker[1:-1,1:-1]=0
while True:
    tmp=marker.copy()
    marker=cv2.dilate(marker, kernel2)
    marker=cv2.min(thresh, marker)
    difference = cv2.subtract(marker, tmp)
    if cv2.countNonZero(difference) == 0:
        break

mask=cv2.bitwise_not(marker)
mask_color = cv2.cvtColor(mask, cv2.COLOR_GRAY2BGR)
out=cv2.bitwise_and(img, mask_color)
cv2.imwrite('out.png', out)
cv2.imshow('result', out )
cv2.waitKey(0) # waits until a key is pressed
cv2.destroyAllWindows()

Answer 2

这就是我在 Python/OpenCV 中解决问题的方式。在周围添加一个白色边框，用黑色填充它以替换白色，然后删除多余的边框。

输入：

import cv2
import numpy as np

# read image
img = cv2.imread('lungs.jpg')
h, w = img.shape[:2]

# convert to gray
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# add 1 pixel white border all around
pad = cv2.copyMakeBorder(gray, 1,1,1,1, cv2.BORDER_CONSTANT, value=255)
h, w = pad.shape

# create zeros mask 2 pixels larger in each dimension
mask = np.zeros([h + 2, w + 2], np.uint8)

# floodfill outer white border with black
img_floodfill = cv2.floodFill(pad, mask, (0,0), 0, (5), (0), flags=8)[1]

# remove border
img_floodfill = img_floodfill[1:h-1, 1:w-1]    

# save cropped image
cv2.imwrite('lungs_floodfilled.png',img_floodfill)

# show the images
cv2.imshow("img_floodfill", img_floodfill)
cv2.waitKey(0)
cv2.destroyAllWindows()

删除附加到图像边框的元素

remove the element attached to the image border

python

opencv

image-processing

detection