如何使用Python在图像中裁剪矩形形状

时间:2018-03-07 06:02:43

标签: python opencv image-processing

有人可以就如何裁剪两个矩形框并保存它给我建议吗?

http://www.unicode.org/glossary/#supplementary_code_point

我已经尝试过这段代码,但效果并不理想

import cv2;
import numpy as np;

# Run the code with the image name, keep pressing space bar

# Change the kernel, iterations, Contour Area, position accordingly
# These values work for your present image

img = cv2.imread("your_image.jpg", 0);
h, w = img.shape[:2]
kernel = np.ones((15,15),np.uint8)

e = cv2.erode(img,kernel,iterations = 2)  
d = cv2.dilate(e,kernel,iterations = 1)
ret, th = cv2.threshold(d, 150, 255, cv2.THRESH_BINARY_INV)

mask = np.zeros((h+2, w+2), np.uint8)
cv2.floodFill(th, mask, (200,200), 255); # position = (200,200)
out = cv2.bitwise_not(th)
out= cv2.dilate(out,kernel,iterations = 3)
cnt, h = cv2.findContours(out,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
for i in range(len(cnt)):
            area = cv2.contourArea(cnt[i])
            if(area>10000 and area<100000):
                  mask = np.zeros_like(img)
                  cv2.drawContours(mask, cnt, i, 255, -1)
                  x,y,w,h = cv2.boundingRect(cnt[i])
                  crop= img[ y:h+y,x:w+x]
                  cv2.imshow("snip",crop )
                  if(cv2.waitKey(0))==27:break

cv2.destroyAllWindows()

这是结果。它只能裁剪较小的盒子。我想要的是裁剪两个方格。

sample image

1 个答案:

答案 0 :(得分:1)

如果你有矩形的坐标,你可以尝试:

cropped = img [y1:y2, x1:x2]

cv2.imwrite('cropped.png', cropped)

第一行在给定坐标上裁剪图像(假设为y1