如何删除此图像的特定颜色？

Question

我想删除图像的所有米色 Brain Image，从而得到其他颜色（棕色、绿色、黄色和红色）。我尝试使用删除白色背景的相同代码来执行此操作，仅修改 RGB 代码，但没有成功。（抱歉，如果在 post 上犯了一些错误）

import cv2 
import numpy as np

# Read image
img = cv2.imread(r'D:\PY\mk1\mk1\sagitale1.png')
hh, ww = img.shape[:2]

# threshold on white
# Define lower and uppper limits
lower = np.array([101, 69, 51])
upper = np.array([255, 171, 142])

# Create mask to only select black
thresh = cv2.inRange(img, lower, upper)

# apply morphology
kernel = cv2.getStructuringElement(cv2.MORPH_ELLIPSE,(20,20))
morph = cv2.morphologyEx(thresh, cv2.MORPH_CLOSE, kernel)

# invert morp image
mask = 255 - thresh

# apply mask to image
result = cv2.bitwise_and(img, img, mask=mask)


# save results
cv2.imwrite('1_thresh.jpg', thresh)
cv2.imwrite('1_result.jpg', result)


cv2.imshow('result', result)
cv2.waitKey(0)
cv2.destroyAllWindows()

Answer 1

你的颜色顺序相反。 OpenCV 按 B、G、R 顺序使用颜色。你需要稍微改变你的范围。你也不需要形态学。

所以以下内容对我来说 Python/OpenCV。

输入：

import cv2 
import numpy as np

# Read image
img = cv2.imread('brain.png')
hh, ww = img.shape[:2]

# threshold on white
# Define lower and uppper limits
lower = np.array([90, 120, 200])
upper = np.array([170, 200, 255])

# Create mask to only select black
thresh = cv2.inRange(img, lower, upper)

# invert threshold image
mask = 255 - thresh

# apply mask to image
result = cv2.bitwise_and(img, img, mask=mask)

# save results
cv2.imwrite('1_thresh.jpg', thresh)
cv2.imwrite('1_result.jpg', result)

cv2.imshow('thresh', thresh)
cv2.imshow('mask', mask)
cv2.imshow('result', result)
cv2.waitKey(0)
cv2.destroyAllWindows()

阈值图像：

结果：

如何删除此图像的特定颜色？

How can I remove especific color of this image?

python

opencv

numpy