CV2 不保存图像

Question

The code is supposed to save the roi I have set using the coordinates of detected objects. No errors were found on this part, but it doesnt save the image.

path = "C:\HelmetDetection"

dt = str(datetime.now().strftime("%Y%m%d-%H:%M:%S"))

overlapping = bool()

instance = None

def check_if_overlapping(x1, y1, trc1, blc1, x2, y2, trc2, blc2):
    check_instance(x1, y1, trc1, blc1, x2, y2, trc2, blc2)
    if instance == "ins1":
        global overlapping
        overlapping = True
    else:
        overlapping = False

def save_image(roi):
    status = cv2.imwrite(os.path.join(path, dt + '.jpg'), roi)
    print(status)

def check_instance(x1, y1, trc1, blc1, x2, y2, trc2, blc2):
    global instance
    if x1 < x2 and y1 > y2 and trc1 > trc2 and blc1 < blc2:
        instance = "ins1"

if label == "motorcycle":
    cv2.rectangle(img, (x, y), (x + w, y + h), (0, 0, 0), 1)
    cv2.putText(img, label + " " + f'{confidence * 100}%', (x, y + 20), font, 1, (0, 0, 0), 1)
    mcoords = []
    mcoords.append((x, y, x + w, y + h))
    if len(mcoords) == 1:
        x1, y1, trc1, blc1 = x, y, x + w, y + h
    else:
        x1, y1, trc1, blc1 = mcoords[0]
if label == "bicycle":
    cv2.rectangle(img, (x, y), (x + w, y + h), (0, 0, 0), 1)
    cv2.putText(img, label + " " + f'{confidence * 100}%', (x, y + 20), font, 1, (0, 0, 0), 1)
    x1, y1, trc1, blc1 = x, y, x + w, y + h
    bcoords = []
    bcoords.append((x, y, x + w, y + h))
    if len(bcoords) == 1:
        x1, y1, trc1, blc1 = x, y, x + w, y + h
    else:
        x1, y1, trc1, blc1 = bcoords[0]
if label == "person":
    cv2.rectangle(img, (x, y), (x + w, y + h), (0, 0, 0), 1)
    cv2.putText(img, label + " " + f'{confidence * 100}%', (x, y + 20), font, 1, (0, 0, 0), 1)
    hcoords = []
    hcoords.append((x, y, x + w, y + h))
    if len(hcoords) == 1:
         x2, y2, trc2, blc2 = x, y, x + w, y + h
    else:
         x2, y2, trc2, blc2 = hcoords[0]
if 'x1' and 'y1' and 'trc1' and 'blc1' and 'x2' and 'y2' and 'trc2' and 'blc2' in locals():
    check_if_overlapping(x1, y1, trc1, blc1, x2, y2, trc2, blc2)

!!!
if overlapping == True:
    check_instance()
    if instance == "ins1":
        if (y2 or blc2 or x1 or trc1) > 100: 
            roi = img[y2 - 100:blc2 + 100, x1 - 100:trc1 + 100]
            save_image(roi)
!!!

It returns False, which as I have read, means the image failed to save. Can I get some easily understandable solutions?

A/N: These are just snippets, it is kind of a long project, so just tell me if you need more information about the codes used.

Answer 1

Something I always like to do is to test my filepath setup using open() as it throws much more useful errors.

In your case it throws an invalid path error, which if you start eliminating weird characters is due to the “:##:” in the date/time format

I would recommend switching your format to not contain colons