+/*
+ Text detection model: https://github.com/argman/EAST
+ Download link: https://www.dropbox.com/s/r2ingd0l3zt8hxs/frozen_east_text_detection.tar.gz?dl=1
+
+ 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
+
+ import torch
+ import models.crnn as 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)
+*/
+
#include <opencv2/imgproc.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/dnn.hpp>
const char* keys =
"{ help h | | Print help message. }"
"{ input i | | Path to input image or video file. Skip this argument to capture frames from a camera.}"
- "{ model m | | Path to a binary .pb file contains trained network.}"
+ "{ model m | | Path to a binary .pb file contains trained detector network.}"
+ "{ ocr | | Path to a binary .pb or .onnx file contains trained recognition network.}"
"{ width | 320 | Preprocess input image by resizing to a specific width. It should be multiple by 32. }"
"{ height | 320 | Preprocess input image by resizing to a specific height. It should be multiple by 32. }"
"{ thr | 0.5 | Confidence threshold. }"
"{ nms | 0.4 | Non-maximum suppression threshold. }";
-void decode(const Mat& scores, const Mat& geometry, float scoreThresh,
- std::vector<RotatedRect>& detections, std::vector<float>& confidences);
+void decodeBoundingBoxes(const Mat& scores, const Mat& geometry, float scoreThresh,
+ std::vector<RotatedRect>& detections, std::vector<float>& confidences);
+
+void fourPointsTransform(const Mat& frame, Point2f vertices[4], Mat& result);
+
+void decodeText(const Mat& scores, std::string& text);
int main(int argc, char** argv)
{
// Parse command line arguments.
CommandLineParser parser(argc, argv, keys);
parser.about("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)");
+ "EAST: An Efficient and Accurate Scene Text Detector (https://arxiv.org/abs/1704.03155v2)");
if (argc == 1 || parser.has("help"))
{
parser.printMessage();
float nmsThreshold = parser.get<float>("nms");
int inpWidth = parser.get<int>("width");
int inpHeight = parser.get<int>("height");
- String model = parser.get<String>("model");
+ String modelDecoder = parser.get<String>("model");
+ String modelRecognition = parser.get<String>("ocr");
if (!parser.check())
{
return 1;
}
- CV_Assert(!model.empty());
+ CV_Assert(!modelDecoder.empty());
+
+ // Load networks.
+ Net detector = readNet(modelDecoder);
+ Net recognizer;
- // Load network.
- Net net = readNet(model);
+ if (!modelRecognition.empty())
+ recognizer = readNet(modelRecognition);
// Open a video file or an image file or a camera stream.
VideoCapture cap;
- if (parser.has("input"))
- cap.open(parser.get<String>("input"));
- else
- cap.open(0);
+ bool openSuccess = parser.has("input") ? cap.open(parser.get<String>("input")) : cap.open(0);
+ CV_Assert(openSuccess);
static const std::string kWinName = "EAST: An Efficient and Accurate Scene Text Detector";
namedWindow(kWinName, WINDOW_NORMAL);
outNames[1] = "feature_fusion/concat_3";
Mat frame, blob;
+ TickMeter tickMeter;
while (waitKey(1) < 0)
{
cap >> frame;
}
blobFromImage(frame, blob, 1.0, Size(inpWidth, inpHeight), Scalar(123.68, 116.78, 103.94), true, false);
- net.setInput(blob);
- net.forward(outs, outNames);
+ detector.setInput(blob);
+ tickMeter.start();
+ detector.forward(outs, outNames);
+ tickMeter.stop();
Mat scores = outs[0];
Mat geometry = outs[1];
// Decode predicted bounding boxes.
std::vector<RotatedRect> boxes;
std::vector<float> confidences;
- decode(scores, geometry, confThreshold, boxes, confidences);
+ decodeBoundingBoxes(scores, geometry, confThreshold, boxes, confidences);
// Apply non-maximum suppression procedure.
std::vector<int> indices;
NMSBoxes(boxes, confidences, confThreshold, nmsThreshold, indices);
- // Render detections.
Point2f ratio((float)frame.cols / inpWidth, (float)frame.rows / inpHeight);
+
+ // Render text.
for (size_t i = 0; i < indices.size(); ++i)
{
RotatedRect& box = boxes[indices[i]];
Point2f vertices[4];
box.points(vertices);
+
for (int j = 0; j < 4; ++j)
{
vertices[j].x *= ratio.x;
vertices[j].y *= ratio.y;
}
+
+ if (!modelRecognition.empty())
+ {
+ Mat cropped;
+ fourPointsTransform(frame, vertices, cropped);
+
+ cvtColor(cropped, cropped, cv::COLOR_BGR2GRAY);
+
+ Mat blobCrop = blobFromImage(cropped, 1.0/127.5, Size(), Scalar::all(127.5));
+ recognizer.setInput(blobCrop);
+
+ tickMeter.start();
+ Mat result = recognizer.forward();
+ tickMeter.stop();
+
+ std::string wordRecognized = "";
+ decodeText(result, wordRecognized);
+ putText(frame, wordRecognized, vertices[1], FONT_HERSHEY_SIMPLEX, 1.5, Scalar(0, 0, 255));
+ }
+
for (int j = 0; j < 4; ++j)
line(frame, vertices[j], vertices[(j + 1) % 4], Scalar(0, 255, 0), 1);
}
// Put efficiency information.
- std::vector<double> layersTimes;
- double freq = getTickFrequency() / 1000;
- double t = net.getPerfProfile(layersTimes) / freq;
- std::string label = format("Inference time: %.2f ms", t);
+ std::string label = format("Inference time: %.2f ms", tickMeter.getTimeMilli());
putText(frame, label, Point(0, 15), FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 255, 0));
imshow(kWinName, frame);
+
+ tickMeter.reset();
}
return 0;
}
-void decode(const Mat& scores, const Mat& geometry, float scoreThresh,
- std::vector<RotatedRect>& detections, std::vector<float>& confidences)
+void decodeBoundingBoxes(const Mat& scores, const Mat& geometry, float scoreThresh,
+ std::vector<RotatedRect>& detections, std::vector<float>& confidences)
{
detections.clear();
CV_Assert(scores.dims == 4); CV_Assert(geometry.dims == 4); CV_Assert(scores.size[0] == 1);
}
}
}
+
+void fourPointsTransform(const Mat& frame, Point2f vertices[4], Mat& result)
+{
+ const Size outputSize = Size(100, 32);
+
+ Point2f targetVertices[4] = {Point(0, outputSize.height - 1),
+ Point(0, 0), Point(outputSize.width - 1, 0),
+ Point(outputSize.width - 1, outputSize.height - 1),
+ };
+ Mat rotationMatrix = getPerspectiveTransform(vertices, targetVertices);
+
+ warpPerspective(frame, result, rotationMatrix, outputSize);
+}
+
+void decodeText(const Mat& scores, std::string& text)
+{
+ static const std::string alphabet = "0123456789abcdefghijklmnopqrstuvwxyz";
+ Mat scoresMat = scores.reshape(1, scores.size[0]);
+
+ std::vector<char> elements;
+ elements.reserve(scores.size[0]);
+
+ for (int rowIndex = 0; rowIndex < scoresMat.rows; ++rowIndex)
+ {
+ Point p;
+ minMaxLoc(scoresMat.row(rowIndex), 0, 0, 0, &p);
+ if (p.x > 0 && static_cast<size_t>(p.x) <= alphabet.size())
+ {
+ elements.push_back(alphabet[p.x - 1]);
+ }
+ else
+ {
+ elements.push_back('-');
+ }
+ }
+
+ if (elements.size() > 0 && elements[0] != '-')
+ text += elements[0];
+
+ for (size_t elementIndex = 1; elementIndex < elements.size(); ++elementIndex)
+ {
+ if (elementIndex > 0 && elements[elementIndex] != '-' &&
+ elements[elementIndex - 1] != elements[elementIndex])
+ {
+ text += elements[elementIndex];
+ }
+ }
+}
\ No newline at end of file