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想在RK3568上实现车牌识别，想到的方法是使用LPRNet网络识别或CRNN识别，本篇记录使用CRNN识别车牌，也可以换成LPRNet模型，原理一样。
一、平台介绍
1、训练平台：Autodl
2、运行板子：ATK-DLRK3568
二、环境搭建
使用Autodl平台的GPU训练测试
1、创建虚拟环境
conda create -n cnn_plate_env python=3.82、激活
conda activate cnn_plate_env3、安装依赖项
pip install easydict -i https://pypi.tuna.tsinghua.edu.cn/simple
pip install pyyaml -i https://pypi.tuna.tsinghua.edu.cn/simple
pip install opencv-python -i https://pypi.tuna.tsinghua.edu.cn/simple
pip install tensorboardX -i https://pypi.tuna.tsinghua.edu.cn/simple
pip install imgaug -i https://pypi.tuna.tsinghua.edu.cn/simple
pip install torch -i https://pypi.tuna.tsinghua.edu.cn/simple
pip install torchvision -i https://pypi.tuna.tsinghua.edu.cn/simple
pip install tensorboardX -i https://pypi.tuna.tsinghua.edu.cn/simple4、下载源码
# 源码地址
https://github.com/we0091234/crnn_plate_recognition5、准备数据集
车牌识别数据集CCPD+CRPD
从CCPD和CRPD截下来的车牌小图以及我自己收集的一部分车牌
数据集打上标签,生成train.txt和val.txt
如有需要，联系博主。
然后执行如下命令，得到train.txt和val.txt
python plateLabel.py --image_path your/train/img/path/ --label_file datasets/train.txt
python plateLabel.py --image_path your/val/img/path/ --label_file datasets/val.txt数据格式如下：
6、修改配置文件
将train.txt val.txt路径写入lib/config/360CC_config.yaml 中
JSON_FILE: {'train': '/root/crnn_plate_recognition/datasets/train.txt', 'val': '/root/crnn_plate_recognition/datasets/val.txt'}注意路径
7、修改trian.py
由于安装的ymal版本过高，会导致无法加载。所以需要修改加载方式。
出错：TypeError: load() missing 1 required positional argument: 'Loader'
处理：TypeError: load() missing 1 required positional argument: ‘Loader‘-CSDN博客
8、训练
python train.py --cfg lib/config/360CC_config.yaml
默认100轮，计时2-3小时，结果保存再output文件夹中
9、测试
python demo.py --model_path saved_model/best.pth --image_path images/test.jpg
三、导出ONNX并推理测试
导出需要安装onnx
pip install onnx
pip install onnxsim1、导出ONNX
python export.py --weights saved_model/best.pth --save_path saved_model/best.onnx --simplify
2、推理测试
python onnx_infer.py --onnx_file saved_model/best.onnx --image_path images/test.jpg
四、转成RKNN
转成RKNN和部署需要用到rknn-toolkit2-1.5.0
把训练转换后的onn拷贝到同级目录下，执行下面转换程序，即可导出RKNN
recongniton_cov_rknn.py
import numpy as np
import cv2
from rknn.api import RKNN
from PIL import Image, ImageDraw, ImageFont
if __name__ == '__main__':
# Create RKNN object
rknn2 = RKNN(verbose=False)
# pre-process config
print('--> Config model')
rknn2.config(mean_values=[[150.54, 150.54, 150.54]], std_values=[[49.215, 49.215, 49.215]], target_platform="rk3568")
print('done')
# Load ONNX model
print('--> Loading model')
ret = rknn2.load_onnx(model="./best.onnx")
if ret != 0:
print('Load model failed!')
exit(ret)
print('done')
# Build model
print('--> Building model')
ret = rknn2.build(do_quantization=False)
if ret != 0:
print('Build model failed!')
exit(ret)
print('done')
# Export RKNN model
print('--> Export rknn model')
ret = rknn2.export_rknn("./best.rknn")
if ret != 0:
print('Export rknn model failed!')
exit(ret)
print('done')
# Init runtime environment
print('--> Init runtime environment')
ret = rknn2.init_runtime()
if ret != 0:
print('Init runtime environment failed!')
exit(ret)
print('done')
rknn2.release()
五、部署测试
把转换后的RKNN模型拷贝到虚拟机内。
测试RKNN模型
import numpy as np
import cv2
from rknn.api import RKNN
from PIL import Image, ImageDraw, ImageFont
plate_chr = "#京沪津渝冀晋蒙辽吉黑苏浙皖闽赣鲁豫鄂湘粤桂琼川贵云藏陕甘青宁新学警港澳挂使领民航危0123456789ABCDEFGHJKLMNPQRSTUVWXYZ险品"
OBJ_THRESH = 0.25
NMS_THRESH = 0.45
IMG_SIZE = 640
CLASSES = ("plate", )
def decodePlate(preds): # 识别后处理
pre = 0
newPreds = []
for i in range(len(preds[0])):
if (preds[0][i] != 0).all() and (preds[0][i] != pre).all():
newPreds.append(preds[0][i])
pre = preds[0][i]
plate = ""
for i in newPreds:
plate += plate_chr[int(i)]
print(plate)
return plate
def cv2ImgAddText(img, text, left, top, textColor=(0, 255, 0), textSize=20):
if (isinstance(img, np.ndarray)): # 判断是否OpenCV图片类型
img = Image.fromarray(cv2.cvtColor(img, cv2.COLOR_BGR2RGB))
# 创建一个可以在给定图像上绘图的对象
draw = ImageDraw.Draw(img)
# 字体的格式
fontStyle = ImageFont.truetype(
"simsun.ttc", textSize, encoding="utf-8")
# 绘制文本
draw.text((left, top), text, textColor, font=fontStyle)
# 转换回OpenCV格式
return cv2.cvtColor(np.asarray(img), cv2.COLOR_RGB2BGR)
def sigmoid(x):
# return 1 / (1 + np.exp(-x))
return x
def xywh2xyxy(x):
# Convert [x, y, w, h] to [x1, y1, x2, y2]
y = np.copy(x)
y[:, 0] = x[:, 0] - x[:, 2] / 2 # top left x
y[:, 1] = x[:, 1] - x[:, 3] / 2 # top left y
y[:, 2] = x[:, 0] + x[:, 2] / 2 # bottom right x
y[:, 3] = x[:, 1] + x[:, 3] / 2 # bottom right y
return y
def process(input, mask, anchors):
anchors = [anchors[i] for i in mask]
grid_h, grid_w = map(int, input.shape[0:2])
box_confidence = sigmoid(input[..., 4])
box_confidence = np.expand_dims(box_confidence, axis=-1)
box_class_probs = sigmoid(input[..., 5:])
box_xy = sigmoid(input[..., :2])*2 - 0.5
col = np.tile(np.arange(0, grid_w), grid_w).reshape(-1, grid_w)
row = np.tile(np.arange(0, grid_h).reshape(-1, 1), grid_h)
col = col.reshape(grid_h, grid_w, 1, 1).repeat(3, axis=-2)
row = row.reshape(grid_h, grid_w, 1, 1).repeat(3, axis=-2)
grid = np.concatenate((col, row), axis=-1)
box_xy += grid
box_xy *= int(IMG_SIZE/grid_h)
box_wh = pow(sigmoid(input[..., 2:4])*2, 2)
box_wh = box_wh * anchors
box = np.concatenate((box_xy, box_wh), axis=-1)
return box, box_confidence, box_class_probs
def filter_boxes(boxes, box_confidences, box_class_probs):
"""Filter boxes with box threshold. It's a bit different with origin yolov5 post process!
# Arguments
boxes: ndarray, boxes of objects.
box_confidences: ndarray, confidences of objects.
box_class_probs: ndarray, class_probs of objects.
# Returns
boxes: ndarray, filtered boxes.
classes: ndarray, classes for boxes.
scores: ndarray, scores for boxes.
"""
boxes = boxes.reshape(-1, 4)
box_confidences = box_confidences.reshape(-1)
box_class_probs = box_class_probs.reshape(-1, box_class_probs.shape[-1])
_box_pos = np.where(box_confidences >= OBJ_THRESH)
boxes = boxes[_box_pos]
box_confidences = box_confidences[_box_pos]
box_class_probs = box_class_probs[_box_pos]
class_max_score = np.max(box_class_probs, axis=-1)
classes = np.argmax(box_class_probs, axis=-1)
_class_pos = np.where(class_max_score >= OBJ_THRESH)
boxes = boxes[_class_pos]
classes = classes[_class_pos]
scores = (class_max_score* box_confidences)[_class_pos]
return boxes, classes, scores
def nms_boxes(boxes, scores):
"""Suppress non-maximal boxes.
# Arguments
boxes: ndarray, boxes of objects.
scores: ndarray, scores of objects.
# Returns
keep: ndarray, index of effective boxes.
"""
x = boxes[:, 0]
y = boxes[:, 1]
w = boxes[:, 2] - boxes[:, 0]
h = boxes[:, 3] - boxes[:, 1]
areas = w * h
order = scores.argsort()[::-1]
keep = []
while order.size > 0:
i = order[0]
keep.append(i)
xx1 = np.maximum(x[i], x[order[1:]])
yy1 = np.maximum(y[i], y[order[1:]])
xx2 = np.minimum(x[i] + w[i], x[order[1:]] + w[order[1:]])
yy2 = np.minimum(y[i] + h[i], y[order[1:]] + h[order[1:]])
w1 = np.maximum(0.0, xx2 - xx1 + 0.00001)
h1 = np.maximum(0.0, yy2 - yy1 + 0.00001)
inter = w1 * h1
ovr = inter / (areas[i] + areas[order[1:]] - inter)
inds = np.where(ovr <= NMS_THRESH)[0]
order = order[inds + 1]
keep = np.array(keep)
return keep
def yolov5_post_process(input_data):
masks = [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
anchors = [[10, 13], [16, 30], [33, 23], [30, 61], [62, 45],
[59, 119], [116, 90], [156, 198], [373, 326]]
boxes, classes, scores = [], [], []
for input, mask in zip(input_data, masks):
b, c, s = process(input, mask, anchors)
b, c, s = filter_boxes(b, c, s)
boxes.append(b)
classes.append(c)
scores.append(s)
boxes = np.concatenate(boxes)
boxes = xywh2xyxy(boxes)
classes = np.concatenate(classes)
scores = np.concatenate(scores)
nboxes, nclasses, nscores = [], [], []
for c in set(classes):
inds = np.where(classes == c)
b = boxes[inds]
c = classes[inds]
s = scores[inds]
keep = nms_boxes(b, s)
nboxes.append(b[keep])
nclasses.append(c[keep])
nscores.append(s[keep])
if not nclasses and not nscores:
return None, None, None
boxes = np.concatenate(nboxes)
classes = np.concatenate(nclasses)
scores = np.concatenate(nscores)
return boxes, classes, scores
def draw(image, boxes, scores, classes):
"""Draw the boxes on the image.
# Argument:
image: original image.
boxes: ndarray, boxes of objects.
classes: ndarray, classes of objects.
scores: ndarray, scores of objects.
all_classes: all classes name.
"""
for box, score, cl in zip(boxes, scores, classes):
top, left, right, bottom = box
# print('class: {}, score: {}'.format(CLASSES[cl], score))
# print('box coordinate left,top,right,down: [{}, {}, {}, {}]'.format(top, left, right, bottom))
top = int(top)
left = int(left)
right = int(right)
bottom = int(bottom)
cv2.rectangle(image, (top, left), (right, bottom), (255, 0, 0), 2)
cv2.putText(image, '{0} {1:.2f}'.format(CLASSES[cl], score),
(top, left - 6),
cv2.FONT_HERSHEY_SIMPLEX,
0.6, (0, 0, 255), 2)
def letterbox(im, new_shape=(640, 640), color=(0, 0, 0)):
# Resize and pad image while meeting stride-multiple constraints
shape = im.shape[:2] # current shape [height, width]
if isinstance(new_shape, int):
new_shape = (new_shape, new_shape)
# Scale ratio (new / old)
r = min(new_shape[0] / shape[0], new_shape[1] / shape[1])
# Compute padding
ratio = r, r # width, height ratios
new_unpad = int(round(shape[1] * r)), int(round(shape[0] * r))
dw, dh = new_shape[1] - new_unpad[0], new_shape[0] - new_unpad[1] # wh padding
dw /= 2 # divide padding into 2 sides
dh /= 2
if shape[::-1] != new_unpad: # resize
im = cv2.resize(im, new_unpad, interpolation=cv2.INTER_LINEAR)
top, bottom = int(round(dh - 0.1)), int(round(dh + 0.1))
left, right = int(round(dw - 0.1)), int(round(dw + 0.1))
im = cv2.copyMakeBorder(im, top, bottom, left, right, cv2.BORDER_CONSTANT, value=color) # add border
return im, ratio, (dw, dh)
if __name__ == '__main__':
# Create RKNN object
rknn1 = RKNN(verbose=False)
rknn2 = RKNN(verbose=False)
# pre-process config
print('--> Config model')
rknn1.config(mean_values=[[0, 0, 0]], std_values=[[255, 255, 255]], target_platform="rk3568")
rknn2.config(mean_values=[[150.54, 150.54, 150.54]], std_values=[[49.215, 49.215, 49.215]], target_platform="rk3568")
print('done')
# Load ONNX model
print('--> Loading model')
ret = rknn1.load_onnx(model="./yolov5n.onnx")
ret = rknn2.load_onnx(model="./best.onnx")
if ret != 0:
print('Load model failed!')
exit(ret)
print('done')
# Build model
print('--> Building model')
ret = rknn1.build(do_quantization=True, dataset="dataset.txt")
ret = rknn2.build(do_quantization=False)
if ret != 0:
print('Build model failed!')
exit(ret)
print('done')
# Export RKNN model
print('--> Export rknn model')
ret = rknn1.export_rknn("./yolov5n.rknn")
ret = rknn2.export_rknn("./best.rknn")
if ret != 0:
print('Export rknn model failed!')
exit(ret)
print('done')
# Init runtime environment
print('--> Init runtime environment')
ret = rknn1.init_runtime()
ret = rknn2.init_runtime()
if ret != 0:
print('Init runtime environment failed!')
exit(ret)
print('done')
# Set inputs
img = cv2.imread("./car.jpg")
# img, ratio, (dw, dh) = letterbox(img, new_shape=(IMG_SIZE, IMG_SIZE))
img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
img = cv2.resize(img, (IMG_SIZE, IMG_SIZE))
# Inference
print('--> Running model')
outputs = rknn1.inference(inputs=[img])
print('done')
# post process
input0_data = outputs[0]
input1_data = outputs[1]
input2_data = outputs[2]
input0_data = input0_data.reshape([3, -1]+list(input0_data.shape[-2:]))
input1_data = input1_data.reshape([3, -1]+list(input1_data.shape[-2:]))
input2_data = input2_data.reshape([3, -1]+list(input2_data.shape[-2:]))
input_data = list()
input_data.append(np.transpose(input0_data, (2, 3, 0, 1)))
input_data.append(np.transpose(input1_data, (2, 3, 0, 1)))
input_data.append(np.transpose(input2_data, (2, 3, 0, 1)))
boxes, classes, scores = yolov5_post_process(input_data)
img_1 = cv2.cvtColor(img, cv2.COLOR_RGB2BGR)
if boxes is not None:
print(boxes)
# draw(img_1, boxes, scores, classes)
for box in boxes:
x1, y1, x2, y2 = box
x1 = int(x1)
x2 = int(x2)
y1 = int(y1)
y2 = int(y2)
cv2.rectangle(img_1, (x1, y1), (x2, y2), (0, 255, 0), 1, 1)
roi = img[y1:y2, x1:x2]
try:
roi = cv2.resize(roi, (168, 48))
print('333')
output = rknn2.inference(inputs=[roi])
input_data = np.swapaxes(output[0], 1, 2)
index = np.argmax(input_data, axis=1)
plate_no = decodePlate(index)
img_1 = cv2ImgAddText(img_1, str(plate_no), x1, y1-30, (0, 255, 0), 30)
print(str(plate_no))
except:
continue
# show output
cv2.imshow("post process result", img_1)
cv2.waitKey(0)
cv2.destroyAllWindows()
rknn1.release()
rknn2.release()
程序大概思路是：
1、读取图片
2、加载模型
3、检测车牌
4、识别车牌
5、显示图片
上面是在虚拟机模拟运行，结果正常。
六、C++板载部署
自行部署，参考讯为电子的程序，可以部署成功。
如有侵权，或需要完整代码，请及时联系博主。