裁剪矩形并显示在 OpenCV Python 中裁剪的图像

Question

I'm new on opencv, I have an original image like this

and I want to crop each licence plate that i've cropped it with this code.

import re
import cv2
import numpy as np

# import tensorflow.lite as tflite
import tflite_runtime.interpreter as tflite # <-- import library

from PIL import Image


def load_labels(label_path):
    with open(label_path) as f:
        labels = {}
        for line in f.readlines():
            m = re.match(r"(\d+)\s+(\w+)", line.strip())
            labels[int(m.group(1))] = m.group(2)
        return labels


def load_model(model_path):
    # interpreter = tf.lite.Interpreter(model_path=args.model_file)
    interpreter = tflite.Interpreter(model_path=model_path)
    interpreter.allocate_tensors()
    return interpreter


def process_image(interpreter, image, input_index):
    input_data = np.expand_dims(image, axis=0)  # expand to 4-dim

    interpreter.set_tensor(input_index, input_data)
    interpreter.invoke()

    output_details = interpreter.get_output_details()
    # print(output_details)
    # output_details[0] - position
    # output_details[1] - class id
    # output_details[2] - score
    # output_details[3] - count

    positions = np.squeeze(interpreter.get_tensor(output_details[0]['index']))
    classes = np.squeeze(interpreter.get_tensor(output_details[1]['index']))
    scores = np.squeeze(interpreter.get_tensor(output_details[2]['index']))
    #confidence = np.squeeze(interpreter.get_tensor(output_details[3]['index']))

    result = []

    for idx, score in enumerate(scores):
        if score > 0.05:
            result.append({'pos': positions[idx], '_id': classes[idx] })
            print(score * 100)

    return result


def display_result(result, frame, labels):

    font = cv2.FONT_HERSHEY_SIMPLEX # <-- font
    size = 0.6
    color = (0, 255, 0)  # warna frame biru
    #color = (255, 131, 23)  # warna oren
    thickness = 1

    # position = [ymin, xmin, ymax, xmax]
    # x * IMAGE_WIDTH
    # y * IMAGE_HEIGHT
    width = frame.shape[1]
    height = frame.shape[0]

    for obj in result:
        pos = obj['pos']
        _id = obj['_id']

        x1 = int(pos[1] * width)
        x2 = int(pos[3] * width)
        y1 = int(pos[0] * height)
        y2 = int(pos[2] * height)

        cv2.putText(frame, labels[_id], (x1, y1), font, size, color, thickness) # <-- munculin font label
        cv2.rectangle(frame, (x1, y1), (x2, y2), color, thickness)

    cv2.imshow('test detect plat-nomor 1', frame)


if __name__ == "__main__":

    #model_path = '/home/smartron01/Documents/tflite/data/coco_ssd_mobilenet_v1_1.0_quant_2018_06_29/detect.tflite'
    model_path = '/home/smartron01/Documents/tflite/numberplate_dr_pak_hermawan/tflite/model.tflite'
    #label_path = '/home/smartron01/Documents/tflite/data/coco_labels.txt'
    label_path = '/home/smartron01/Documents/tflite/numberplate_dr_pak_hermawan/tflite/dict.txt'
    #image_path = '/home/smartron01/Documents/tflite/data/bus.jpg'
    #image_path = '/home/smartron01/Documents/tflite/data/0008A.jpg'
    image_path = '/home/smartron01/Documents/tflite/data/mobil2.jpg'

    interpreter = load_model(model_path)
    labels = load_labels(label_path)

    input_details = interpreter.get_input_details()

    input_shape = input_details[0]['shape']
    height = input_shape[1]
    width = input_shape[2]

    input_index = input_details[0]['index']

    frame = cv2.imread(image_path, cv2.IMREAD_COLOR)
    print(frame.shape) # print model shape

    image = Image.fromarray(cv2.cvtColor(frame, cv2.COLOR_BGR2RGB))
    image = image.resize((width, height))

    top_result = process_image(interpreter, image, input_index)
    display_result(top_result, frame, labels)

    key = cv2.waitKey(0)
    if key == 27:
        cv2.destroyAllWindows()

I created a rectangle in each of license plate and this code gives me this ouput . I want to crop each license-plate in each car, crop it rectangle, and then show image in another window. thankyou.

Answer 1

Hello I'm new to answering questions, but I believe this may help.

I did something similar to this, but it crops faces from images.

You can apply the same concept in your code that draws the rectangles around the license plates to crop the images. The extra code goes with your display_result function.

for obj in result:
        pos = obj['pos']
        _id = obj['_id']

        x1 = int(pos[1] * width)
        x2 = int(pos[3] * width)
        y1 = int(pos[0] * height)
        y2 = int(pos[2] * height)

        cv2.putText(frame, labels[_id], (x1, y1), font, size, color, thickness) # <-- munculin font label
        cv2.rectangle(frame, (x1, y1), (x2, y2), color, thickness)
        #crops plates based on points used to draw each rectangle around plates.
        frame = frame[y1:y2,x1:x2]

    cv2.imshow('test detect plat-nomor 1', frame)

I hope this helps!