OpenCV fillPoly（）不适用于灰度（1通道）图像

Question

so I am using opencv to modify pixel values on a 1-channel image. I create the blank image using

curr = np.zeros((660,512, 1))

then execute the code:

for r in regions:
    cv2.fillPoly(curr, r, [190])

where each region looks something like:

[[[363 588]
  [304 593]
  [323 652]
  [377 654]]]

I know that the code is at least somewhat working, because when I use imshow(), the regions are filled as desired. However, I tried re-accessing the modified pixel values, and got [ 0.] I tried writing the whole img ti a temporary file as follows:

for elt in curr:
    f2.write(str(elt) + '\n')

However, the file just looks like

 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]
 [ 0.]

Where am I going wrong? Why can't I re-access the 190s I wrote to the image?

Answer 1

Works just fine.

curr = np.zeros((660,512, 1),dtype = np.uint8)

regions = np.array([[[363,588],[304,593],[323,652],[377,654]]])

for r in regions:
    cv2.fillPoly(curr, [regions[0]], (190))

# find minimum value, maximum value and their location index in the image
minVal,maxVal,minLoc,maxLoc = cv2.minMaxLoc(curr)

print(maxVal, maxLoc)

Answer 2

maybe you are over-writing or re-initialising image(curr) somewhere in the code, here's the code using cv2.imwrite to save the file.

curr = np.zeros((660,512, 1))
regions = np.random.uniform(1, 200, size=(1, 5, 2))
regions = regions.astype(np.int32, copy=False)
for r in regions:
    cv2.fillPoly(curr, [r], [190])

while(1):
    cv2.imshow('Terry Martin', curr)
    k= cv2.waitKey(1) & 0xFF
    if k == 27:
        cv2.imwrite('FillPloy.jpg', curr)
        break

cv2.destroyAllWindows()

OpenCV Window:

Output image: