问题描述
我想从下面的虹膜图像中裁剪出圆圈:
这是我的圈子检测代码:
from matplotlib import pyplot as plt
import numpy as np
import cv2
gambar = cv2.imread('tes2.jpg',0)
cimg = cv2.cvtColor(gambar,cv2.COLOR_GRAY2BGR)
canny = cv2.Canny(cimg,50,50)
circles = cv2.HoughCircles(canny,cv2.HOUGH_GRADIENT,1,10000,param1=50,param2=30,minRadius=50,maxRadius=200)
circles = np.uint16(np.around(circles))
for i in circles[0,:]:
# draw the outer circle
cv2.circle(cimg,(i[0],i[2]),i[2],(0,255,0),2)
# draw the center of the circle
cv2.circle(cimg,2,255),3)
plt.imshow(cimg,cmap = 'gray')
plt.show()
但是,我不知道如何裁剪该圆圈(虹膜局部化)。我一直在关注此代码参考Cropping circle from the image using OpenCV python。这是我下面的裁剪图像代码:
from matplotlib import pyplot as plt
import numpy as np
import cv2
gambar1 =cv2.imread('tes2.jpg')
gambar = cv2.imread('tes2.jpg',cv2.COLOR_BGR2GRAY)
ret,thresh = cv2.threshold(cimg,cv2.THRESH_BINARY)
# Create mask
height,width = gambar.shape
mask = np.zeros((height,width),np.uint8)
canny = cv2.Canny(thresh,100,200)
gray = cv2.cvtColor(gambar,cv2.COLOR_GRAY2BGR)
circles = cv2.HoughCircles(canny,minRadius=0,maxRadius=0)
for i in circles[0,:]:
cv2.circle(mask,i[1]),(255,thickness=-1)
masked_data = cv2.bitwise_and(gambar1,gambar1,mask=mask)
# Apply Threshold
_,thresh = cv2.threshold(mask,cv2.THRESH_BINARY)
# Find Contour
contours = cv2.findContours(thresh,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
x,y,w,h = cv2.boundingRect(contours[0])
# Crop masked_data
crop = masked_data[y:y+h,x:x+w]
plt.imshow(gambar1,cmap = 'gray')
plt.imshow(crop,cmap='gray')
plt.show()
File "C:/Users/zurri/spyder/masktes.py",line 14,in <module>
cimg = cv2.cvtColor(gambar,cv2.COLOR_BGR2GRAY)
error: OpenCV(4.2.0) c:\projects\opencv-python\opencv\modules\imgproc\src\color.simd_helpers.hpp:92: error: (-2:Unspecified error) in function '__cdecl cv::impl::`anonymous-namespace'::CvtHelper<struct cv::impl::`anonymous namespace'::Set<3,4,-1>,struct cv::impl::A0xe227985e::Set<1,-1,struct cv::impl::A0xe227985e::Set<0,5>,2>::CvtHelper(const class cv::_InputArray &,const class cv::_OutputArray &,int)'
Invalid number of channels in input image:
'VScn::contains(scn)'
where
'scn' is 1
有人可以帮助我解决此问题吗?我只想使用openCV python裁剪此圆圈(虹膜本地化),谢谢
解决方法
说明
findContours
方法使用Suzuki's算法从给定的二进制图像中检索轮廓。轮廓对于形状分析,物体检测和识别很有用。
findContour
方法返回两个变量:contours
和hierarchy
。在原始代码中,您进行了contours = cv2.findContour(...)
合并了contours
和hierarchy
变量的操作。因此,您有一个错误。我们根本不需要hieararchy
变量,因此我们放置了_
。因此错误得以解决。
解决方案
用以下内容替换findContours
行:
contours,_ = cv2.findContours(thresh,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
结果: