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I am trying to create a number plate detection with the following code but it fails when I try to get the plate from the processed image.

plate_cascade = cv2.CascadeClassifier(cv2.data.haarcascades + 'https://raw.githubusercontent.com/SarthakV7/AI-based-indian-license-plate-detection/master/indian_license_plate.xml')

def detect_plate(img, text=''):
    plate_img = img.copy()
    roi = img.copy()
    plate_rect = plate_cascade.detectMultiScale(plate_img, scaleFactor = 1.2, minNeighbors = 7) # detects numberplates and returns the coordinates and dimensions of detected license plate's contours.
    for (x,y,w,h) in plate_rect:
        roi_ = roi[y:y+h, x:x+w, :] 
        plate = roi[y:y+h, x:x+w, :]
        cv2.rectangle(plate_img, (x+2,y), (x+w-3, y+h-5), (51,181,155), 3) 
    if text!='':
        plate_img = cv2.putText(plate_img, text, (x-w//2,y-h//2), 
                                cv2.FONT_HERSHEY_COMPLEX_SMALL , 0.5, (51,181,155), 1, cv2.LINE_AA)
        
    return plate_img, plate # returning the processed image.

# Testing the above function
def display(img_, title=''):
    img = cv2.cvtColor(img_, cv2.COLOR_BGR2RGB)
    fig = plt.figure(figsize=(10,6))
    ax = plt.subplot(111)
    ax.imshow(img)
    plt.axis('off')
    plt.title(title)
    plt.show()

img = io.imread('https:///automatic-giggle/cef27d2274a17835ac4b9c044382131e0fba139d/car_test.jpeg')
display(img, 'input image')


# Getting plate prom the processed image
output_img, plate = detect_plate(img)

I then receive the following error message:

Error: OpenCV(4.6.0) /io/opencv/modules/objdetect/src/cascadedetect.cpp:1689: error: (-215:Assertion failed) !empty() in function 'detectMultiScale'

Christoph Rackwitz
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asaetrang
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  • Does this answer your question? [error: (-215) !empty() in function detectMultiScale](https://stackoverflow.com/questions/30508922/error-215-empty-in-function-detectmultiscale) – Christoph Rackwitz Nov 22 '22 at 21:24
  • welcome. [tour], [ask]. google your errors. do not ask until you've searched well. this has been asked before hundreds of times. – Christoph Rackwitz Nov 22 '22 at 21:24

0 Answers0