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3rdparty/opencv-4.5.4/samples/dnn/text_detection.py 9.13 KB
f4334277   Hu Chunming   提交3rdparty
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  '''
      Text detection model: https://github.com/argman/EAST
      Download link: https://www.dropbox.com/s/r2ingd0l3zt8hxs/frozen_east_text_detection.tar.gz?dl=1
  
      CRNN Text recognition model taken from here: https://github.com/meijieru/crnn.pytorch
      How to convert from pb to onnx:
      Using classes from here: https://github.com/meijieru/crnn.pytorch/blob/master/models/crnn.py
  
      More converted onnx text recognition models can be downloaded directly here:
      Download link: https://drive.google.com/drive/folders/1cTbQ3nuZG-EKWak6emD_s8_hHXWz7lAr?usp=sharing
      And these models taken from here:https://github.com/clovaai/deep-text-recognition-benchmark
  
      import torch
      from models.crnn import CRNN
  
      model = CRNN(32, 1, 37, 256)
      model.load_state_dict(torch.load('crnn.pth'))
      dummy_input = torch.randn(1, 1, 32, 100)
      torch.onnx.export(model, dummy_input, "crnn.onnx", verbose=True)
  '''
  
  
  # Import required modules
  import numpy as np
  import cv2 as cv
  import math
  import argparse
  
  ############ Add argument parser for command line arguments ############
  parser = argparse.ArgumentParser(
      description="Use this script to run TensorFlow implementation (https://github.com/argman/EAST) of "
                  "EAST: An Efficient and Accurate Scene Text Detector (https://arxiv.org/abs/1704.03155v2)"
                  "The OCR model can be obtained from converting the pretrained CRNN model to .onnx format from the github repository https://github.com/meijieru/crnn.pytorch"
                  "Or you can download trained OCR model directly from https://drive.google.com/drive/folders/1cTbQ3nuZG-EKWak6emD_s8_hHXWz7lAr?usp=sharing")
  parser.add_argument('--input',
                      help='Path to input image or video file. Skip this argument to capture frames from a camera.')
  parser.add_argument('--model', '-m', required=True,
                      help='Path to a binary .pb file contains trained detector network.')
  parser.add_argument('--ocr', default="crnn.onnx",
                      help="Path to a binary .pb or .onnx file contains trained recognition network", )
  parser.add_argument('--width', type=int, default=320,
                      help='Preprocess input image by resizing to a specific width. It should be multiple by 32.')
  parser.add_argument('--height', type=int, default=320,
                      help='Preprocess input image by resizing to a specific height. It should be multiple by 32.')
  parser.add_argument('--thr', type=float, default=0.5,
                      help='Confidence threshold.')
  parser.add_argument('--nms', type=float, default=0.4,
                      help='Non-maximum suppression threshold.')
  args = parser.parse_args()
  
  
  ############ Utility functions ############
  
  def fourPointsTransform(frame, vertices):
      vertices = np.asarray(vertices)
      outputSize = (100, 32)
      targetVertices = np.array([
          [0, outputSize[1] - 1],
          [0, 0],
          [outputSize[0] - 1, 0],
          [outputSize[0] - 1, outputSize[1] - 1]], dtype="float32")
  
      rotationMatrix = cv.getPerspectiveTransform(vertices, targetVertices)
      result = cv.warpPerspective(frame, rotationMatrix, outputSize)
      return result
  
  
  def decodeText(scores):
      text = ""
      alphabet = "0123456789abcdefghijklmnopqrstuvwxyz"
      for i in range(scores.shape[0]):
          c = np.argmax(scores[i][0])
          if c != 0:
              text += alphabet[c - 1]
          else:
              text += '-'
  
      # adjacent same letters as well as background text must be removed to get the final output
      char_list = []
      for i in range(len(text)):
          if text[i] != '-' and (not (i > 0 and text[i] == text[i - 1])):
              char_list.append(text[i])
      return ''.join(char_list)
  
  
  def decodeBoundingBoxes(scores, geometry, scoreThresh):
      detections = []
      confidences = []
  
      ############ CHECK DIMENSIONS AND SHAPES OF geometry AND scores ############
      assert len(scores.shape) == 4, "Incorrect dimensions of scores"
      assert len(geometry.shape) == 4, "Incorrect dimensions of geometry"
      assert scores.shape[0] == 1, "Invalid dimensions of scores"
      assert geometry.shape[0] == 1, "Invalid dimensions of geometry"
      assert scores.shape[1] == 1, "Invalid dimensions of scores"
      assert geometry.shape[1] == 5, "Invalid dimensions of geometry"
      assert scores.shape[2] == geometry.shape[2], "Invalid dimensions of scores and geometry"
      assert scores.shape[3] == geometry.shape[3], "Invalid dimensions of scores and geometry"
      height = scores.shape[2]
      width = scores.shape[3]
      for y in range(0, height):
  
          # Extract data from scores
          scoresData = scores[0][0][y]
          x0_data = geometry[0][0][y]
          x1_data = geometry[0][1][y]
          x2_data = geometry[0][2][y]
          x3_data = geometry[0][3][y]
          anglesData = geometry[0][4][y]
          for x in range(0, width):
              score = scoresData[x]
  
              # If score is lower than threshold score, move to next x
              if (score < scoreThresh):
                  continue
  
              # Calculate offset
              offsetX = x * 4.0
              offsetY = y * 4.0
              angle = anglesData[x]
  
              # Calculate cos and sin of angle
              cosA = math.cos(angle)
              sinA = math.sin(angle)
              h = x0_data[x] + x2_data[x]
              w = x1_data[x] + x3_data[x]
  
              # Calculate offset
              offset = ([offsetX + cosA * x1_data[x] + sinA * x2_data[x], offsetY - sinA * x1_data[x] + cosA * x2_data[x]])
  
              # Find points for rectangle
              p1 = (-sinA * h + offset[0], -cosA * h + offset[1])
              p3 = (-cosA * w + offset[0], sinA * w + offset[1])
              center = (0.5 * (p1[0] + p3[0]), 0.5 * (p1[1] + p3[1]))
              detections.append((center, (w, h), -1 * angle * 180.0 / math.pi))
              confidences.append(float(score))
  
      # Return detections and confidences
      return [detections, confidences]
  
  
  def main():
      # Read and store arguments
      confThreshold = args.thr
      nmsThreshold = args.nms
      inpWidth = args.width
      inpHeight = args.height
      modelDetector = args.model
      modelRecognition = args.ocr
  
      # Load network
      detector = cv.dnn.readNet(modelDetector)
      recognizer = cv.dnn.readNet(modelRecognition)
  
      # Create a new named window
      kWinName = "EAST: An Efficient and Accurate Scene Text Detector"
      cv.namedWindow(kWinName, cv.WINDOW_NORMAL)
      outNames = []
      outNames.append("feature_fusion/Conv_7/Sigmoid")
      outNames.append("feature_fusion/concat_3")
  
      # Open a video file or an image file or a camera stream
      cap = cv.VideoCapture(args.input if args.input else 0)
  
      tickmeter = cv.TickMeter()
      while cv.waitKey(1) < 0:
          # Read frame
          hasFrame, frame = cap.read()
          if not hasFrame:
              cv.waitKey()
              break
  
          # Get frame height and width
          height_ = frame.shape[0]
          width_ = frame.shape[1]
          rW = width_ / float(inpWidth)
          rH = height_ / float(inpHeight)
  
          # Create a 4D blob from frame.
          blob = cv.dnn.blobFromImage(frame, 1.0, (inpWidth, inpHeight), (123.68, 116.78, 103.94), True, False)
  
          # Run the detection model
          detector.setInput(blob)
  
          tickmeter.start()
          outs = detector.forward(outNames)
          tickmeter.stop()
  
          # Get scores and geometry
          scores = outs[0]
          geometry = outs[1]
          [boxes, confidences] = decodeBoundingBoxes(scores, geometry, confThreshold)
  
          # Apply NMS
          indices = cv.dnn.NMSBoxesRotated(boxes, confidences, confThreshold, nmsThreshold)
          for i in indices:
              # get 4 corners of the rotated rect
              vertices = cv.boxPoints(boxes[i[0]])
              # scale the bounding box coordinates based on the respective ratios
              for j in range(4):
                  vertices[j][0] *= rW
                  vertices[j][1] *= rH
  
  
              # get cropped image using perspective transform
              if modelRecognition:
                  cropped = fourPointsTransform(frame, vertices)
                  cropped = cv.cvtColor(cropped, cv.COLOR_BGR2GRAY)
  
                  # Create a 4D blob from cropped image
                  blob = cv.dnn.blobFromImage(cropped, size=(100, 32), mean=127.5, scalefactor=1 / 127.5)
                  recognizer.setInput(blob)
  
                  # Run the recognition model
                  tickmeter.start()
                  result = recognizer.forward()
                  tickmeter.stop()
  
                  # decode the result into text
                  wordRecognized = decodeText(result)
                  cv.putText(frame, wordRecognized, (int(vertices[1][0]), int(vertices[1][1])), cv.FONT_HERSHEY_SIMPLEX,
                             0.5, (255, 0, 0))
  
              for j in range(4):
                  p1 = (int(vertices[j][0]), int(vertices[j][1]))
                  p2 = (int(vertices[(j + 1) % 4][0]), int(vertices[(j + 1) % 4][1]))
                  cv.line(frame, p1, p2, (0, 255, 0), 1)
  
          # Put efficiency information
          label = 'Inference time: %.2f ms' % (tickmeter.getTimeMilli())
          cv.putText(frame, label, (0, 15), cv.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0))
  
          # Display the frame
          cv.imshow(kWinName, frame)
          tickmeter.reset()
  
  
  if __name__ == "__main__":
      main()