python - 使用opencv python检测二进制图像中的补丁
问题描述
我想在此处检测输入图像描述中的所有补丁图像,我附上了用于检测它们的代码:
import cv2
import numpy as np
import matplotlib.pyplot as plt
image=cv2.imread("bw2.jpg",0)
# convert to RGB
image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
# convert to grayscale
gray = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)
# create a binary thresholded image
_, binary = cv2.threshold(gray, 0, 500, cv2.THRESH_BINARY_INV)
# show it
plt.imshow(gray, cmap="gray")
plt.show()
# find the contours from the thresholded image
contours, hierarchy = cv2.findContours(gray, cv2.RETR_TREE,
cv2.CHAIN_APPROX_SIMPLE)
print("contours:",contours)
# draw all contours
for c in contours:
if cv2.contourArea(c) < 3000:
continue
(x, y, w, h) = cv2.boundingRect(c)
#cv2.rectangle(image, (x,y), (x+w,y+h), (0, 255, 0), 2)
## BEGIN - draw rotated rectangle
rect = cv2.minAreaRect(c)
box = cv2.boxPoints(rect)
box = np.int0(box)
cv2.drawContours(image,[box],0,(255,51,255),2)
# show the image with the drawn contours
plt.imshow(image)
#plt.imshow(im3)
cv2.imwrite("detectImg2.png",image)
plt.show()
我得到输出图像,在这里输入图像描述
我想检测所有这些,谁能告诉我如何实现这一点我是图像处理的新手
解决方案
这是我如何使用 Python OpenCV 提取和旋转图像中的每个 blob。
- 读取输入
- 转换为灰色
- 临界点
- 打开和关闭应用形态以清洁小斑点
- 获取所有外部轮廓
- 循环遍历每个轮廓并执行以下操作:
- 在输入图像的副本上绘制轮廓
- 获取轮廓的旋转矩形并提取其中心、尺寸和旋转角度
- 获取旋转矩形的角
- 在输入的另一个副本上绘制旋转的矩形
- 校正图像未旋转的旋转角度
- 使用填充的旋转矩形生成蒙版图像
- 将蒙版图像应用于形态清洁图像以去除附近的其他白色区域
- 使用中心和校正的旋转角度获取仿射扭曲矩阵
- 使用 warpAffine 未旋转蒙版图像
- 获取未旋转图像中一个斑点的轮廓
- 获取轮廓边界框
- 裁剪蒙版图像(或交替裁剪输入图像)
- 保存裁剪的图像
- 退出循环
- 保存轮廓和 rotrect 图像
输入:
import cv2
import numpy as np
image = cv2.imread("bw2.jpg")
hh, ww = image.shape[:2]
# convert to grayscale
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
# create a binary thresholded image
thresh = cv2.threshold(gray, 0, 255, cv2.THRESH_BINARY+cv2.THRESH_OTSU)[1]
# apply morphology
kernel = np.ones((7,7), np.uint8)
clean = cv2.morphologyEx(thresh, cv2.MORPH_OPEN, kernel)
kernel = np.ones((13,13), np.uint8)
clean = cv2.morphologyEx(clean, cv2.MORPH_CLOSE, kernel)
# get external contours
contours = cv2.findContours(clean, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
contours = contours[0] if len(contours) == 2 else contours[1]
contour_img = image.copy()
rotrect_img = image.copy()
i = 1
for c in contours:
# draw contour on input
cv2.drawContours(contour_img,[c],0,(0,0,255),2)
# get rotated rectangle from contour
# get its dimensions
# get angle relative to horizontal from rotated rectangle
rotrect = cv2.minAreaRect(c)
(center), (width,height), angle = rotrect
box = cv2.boxPoints(rotrect)
boxpts = np.int0(box)
# draw rotated rectangle on copy of image
cv2.drawContours(rotrect_img,[boxpts],0,(0,255,0),2)
# from https://www.pyimagesearch.com/2017/02/20/text-skew-correction-opencv-python/
# the `cv2.minAreaRect` function returns values in the
# range [-90, 0); as the rectangle rotates clockwise the
# returned angle tends to 0 -- in this special case we
# need to add 90 degrees to the angle
if angle < -45:
angle = -(90 + angle)
# otherwise, check width vs height
else:
if width > height:
angle = -(90 + angle)
else:
angle = -angle
# negate the angle for deskewing
neg_angle = -angle
# draw mask as filled rotated rectangle on black background the size of the input
mask = np.zeros_like(clean)
cv2.drawContours(mask,[boxpts],0,255,-1)
# apply mask to cleaned image
blob_img = cv2.bitwise_and(clean, mask)
# Get rotation matrix
#center = (width // 2, height // 2)
M = cv2.getRotationMatrix2D(center, neg_angle, scale=1.0)
#print('m: ',M)
# deskew (unrotate) the rotated rectangle
deskewed = cv2.warpAffine(blob_img, M, (ww, hh), flags=cv2.INTER_CUBIC, borderMode=cv2.BORDER_REPLICATE)
# threshold it again
deskewed = cv2.threshold(deskewed, 0, 255, cv2.THRESH_BINARY+cv2.THRESH_OTSU)[1]
# get bounding box of contour of deskewed rectangle
cntrs = cv2.findContours(deskewed, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
cntrs = cntrs[0] if len(cntrs) == 2 else cntrs[1]
cntr = cntrs[0]
x,y,w,h = cv2.boundingRect(cntr)
# crop to white region
crop = deskewed[y:y+h, x:x+w]
# alternately crop the input
#crop = image[y:y+h, x:x+w]
# save deskewed image
cv2.imwrite("bw2_deskewed_{0}.png".format(i),crop)
print("")
i = i + 1
# save contour and rot rect images
cv2.imwrite("bw2_contours.png",contour_img)
cv2.imwrite("bw2_rotrects.png",rotrect_img)
# display result, though it won't show transparency
cv2.imshow("thresh", thresh)
cv2.imshow("clean", clean)
cv2.imshow("contours", contour_img)
cv2.imshow("rectangles", rotrect_img)
cv2.waitKey(0)
cv2.destroyAllWindows()
轮廓图:
旋转矩形图像:
前 3 张未旋转的图像:
仿射扭曲旋转角度:
13.916877746582031
-42.87890625
18.8118896484375
-44.333797454833984
-38.65980911254883
-37.25965881347656
8.806793212890625
14.931419372558594
-37.405357360839844
-34.99202346801758
35.537681579589844
-35.350345611572266
-42.3245735168457
50.12316131591797
-42.969085693359375
52.750038146972656
45.0