opencv边界框问题

我有一个图像需要在周围绘制一个边界框，我正在尝试使用本文底部的代码。 我遇到的问题是我尝试模糊蓝色框形状以删除其细节，例如

cv2.blur(img,(20,20)) 

但模糊图像似乎没有足够好的边缘来生成边界框。

我发现，如果我将下面的代码与具有与下图相同大小的锐边的纯蓝色正方形一起使用，则效果很好。蓝色区域内的细节似乎阻止了边界框的绘制。

我希望有人能告诉我如何让它发挥作用。

import cv2

# Load the image - container completely blurred out so no hinges,locking bars , writing etc are visible, just a blank blue square
img = cv2.imread('blue_object.jpg')

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

edged = cv2.Canny(img, 120,890)
# Apply adaptive threshold
thresh = cv2.adaptiveThreshold(edged, 255, 1, 1, 11, 2)
thresh_color = cv2.cvtColor(thresh, cv2.COLOR_GRAY2BGR)

# apply some dilation and erosion to join the gaps - change iteration to detect more or less area's
thresh = cv2.dilate(thresh,None,iterations = 50)
thresh = cv2.erode(thresh,None,iterations = 50)

# Find the contours
contours,hierarchy = cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)

# For each contour, find the bounding rectangle and draw it
for cnt in contours:
    area = cv2.contourArea(cnt)
    if area > 50000:
        x,y,w,h = cv2.boundingRect(cnt)
        cv2.rectangle(img,(x,y),(x+w,y+h),(0,255,0),2)


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

The image below is the yellow container after lower HSV mask range of 8,0,0 and upper range of 78,255,255 . Trees are above and to top right of the container, so hard to separate the tress from the container to put a proper bounding box around it.Happy to move to chat if that helps.

你正在变成灰色，扔掉所有有价值的东西颜色信息离开。你也很精明，这通常是一个坏主意。初学者没有判断力来明智地应用 Canny。最好远离它。

这个问题可以用通常的方法来解决：

• 将色彩空间转换为有用的东西，比如 HSV
• inRange on 饱和度良好的蓝色
• 一些形态学操作来清理碎片
• 边界框

假设您正在寻找蓝色容器，或任何饱和度良好的颜色。

im = cv.imread("i4nPk.jpg")
hsv = cv.cvtColor(im, cv.COLOR_BGR2HSV)

lower = (90, 84, 0)
upper = (180, 255, 255)
mask1 = cv.inRange(hsv, lower, upper)

mask2 = cv.erode(mask1, kernel=None, iterations=2)

(x, y, w, h) = cv.boundingRect(mask2) # yes that works on masks too

canvas = cv.cvtColor(mask2, cv.COLOR_GRAY2BGR)
cv.rectangle(canvas, (x,y), (x+w, y+h), color=(0,0,255), thickness=3)