cameracv/libs/opencv/modules/gapi/samples/text_detection.cpp
2023-05-18 21:39:43 +03:00

698 lines
27 KiB
C++

#include <algorithm>
#include <cctype>
#include <cmath>
#include <iostream>
#include <limits>
#include <numeric>
#include <stdexcept>
#include <string>
#include <vector>
#include <opencv2/gapi.hpp>
#include <opencv2/gapi/core.hpp>
#include <opencv2/gapi/cpu/gcpukernel.hpp>
#include <opencv2/gapi/infer.hpp>
#include <opencv2/gapi/infer/ie.hpp>
#include <opencv2/gapi/streaming/cap.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/core/utility.hpp>
const std::string about =
"This is an OpenCV-based version of OMZ Text Detection example";
const std::string keys =
"{ h help | | Print this help message }"
"{ input | | Path to the input video file }"
"{ tdm | text-detection-0004.xml | Path to OpenVINO text detection model (.xml), versions 0003 and 0004 work }"
"{ tdd | CPU | Target device for the text detector (e.g. CPU, GPU, VPU, ...) }"
"{ trm | text-recognition-0012.xml | Path to OpenVINO text recognition model (.xml) }"
"{ trd | CPU | Target device for the text recognition (e.g. CPU, GPU, VPU, ...) }"
"{ bw | 0 | CTC beam search decoder bandwidth, if 0, a CTC greedy decoder is used}"
"{ sset | 0123456789abcdefghijklmnopqrstuvwxyz | Symbol set to use with text recognition decoder. Shouldn't contain symbol #. }"
"{ thr | 0.2 | Text recognition confidence threshold}"
;
namespace {
std::string weights_path(const std::string &model_path) {
const auto EXT_LEN = 4u;
const auto sz = model_path.size();
CV_Assert(sz > EXT_LEN);
const auto ext = model_path.substr(sz - EXT_LEN);
CV_Assert(cv::toLowerCase(ext) == ".xml");
return model_path.substr(0u, sz - EXT_LEN) + ".bin";
}
//////////////////////////////////////////////////////////////////////
// Taken from OMZ samples as-is
template<typename Iter>
void softmax_and_choose(Iter begin, Iter end, int *argmax, float *prob) {
auto max_element = std::max_element(begin, end);
*argmax = static_cast<int>(std::distance(begin, max_element));
float max_val = *max_element;
double sum = 0;
for (auto i = begin; i != end; i++) {
sum += std::exp((*i) - max_val);
}
if (std::fabs(sum) < std::numeric_limits<double>::epsilon()) {
throw std::logic_error("sum can't be equal to zero");
}
*prob = 1.0f / static_cast<float>(sum);
}
template<typename Iter>
std::vector<float> softmax(Iter begin, Iter end) {
std::vector<float> prob(end - begin, 0.f);
std::transform(begin, end, prob.begin(), [](float x) { return std::exp(x); });
float sum = std::accumulate(prob.begin(), prob.end(), 0.0f);
for (int i = 0; i < static_cast<int>(prob.size()); i++)
prob[i] /= sum;
return prob;
}
struct BeamElement {
std::vector<int> sentence; //!< The sequence of chars that will be a result of the beam element
float prob_blank; //!< The probability that the last char in CTC sequence
//!< for the beam element is the special blank char
float prob_not_blank; //!< The probability that the last char in CTC sequence
//!< for the beam element is NOT the special blank char
float prob() const { //!< The probability of the beam element.
return prob_blank + prob_not_blank;
}
};
std::string CTCGreedyDecoder(const float *data,
const std::size_t sz,
const std::string &alphabet,
const char pad_symbol,
double *conf) {
std::string res = "";
bool prev_pad = false;
*conf = 1;
const auto num_classes = alphabet.length();
for (auto it = data; it != (data+sz); it += num_classes) {
int argmax = 0;
float prob = 0.f;
softmax_and_choose(it, it + num_classes, &argmax, &prob);
(*conf) *= prob;
auto symbol = alphabet[argmax];
if (symbol != pad_symbol) {
if (res.empty() || prev_pad || (!res.empty() && symbol != res.back())) {
prev_pad = false;
res += symbol;
}
} else {
prev_pad = true;
}
}
return res;
}
std::string CTCBeamSearchDecoder(const float *data,
const std::size_t sz,
const std::string &alphabet,
double *conf,
int bandwidth) {
const auto num_classes = alphabet.length();
std::vector<BeamElement> curr;
std::vector<BeamElement> last;
last.push_back(BeamElement{std::vector<int>(), 1.f, 0.f});
for (auto it = data; it != (data+sz); it += num_classes) {
curr.clear();
std::vector<float> prob = softmax(it, it + num_classes);
for(const auto& candidate: last) {
float prob_not_blank = 0.f;
const std::vector<int>& candidate_sentence = candidate.sentence;
if (!candidate_sentence.empty()) {
int n = candidate_sentence.back();
prob_not_blank = candidate.prob_not_blank * prob[n];
}
float prob_blank = candidate.prob() * prob[num_classes - 1];
auto check_res = std::find_if(curr.begin(),
curr.end(),
[&candidate_sentence](const BeamElement& n) {
return n.sentence == candidate_sentence;
});
if (check_res == std::end(curr)) {
curr.push_back(BeamElement{candidate.sentence, prob_blank, prob_not_blank});
} else {
check_res->prob_not_blank += prob_not_blank;
if (check_res->prob_blank != 0.f) {
throw std::logic_error("Probability that the last char in CTC-sequence "
"is the special blank char must be zero here");
}
check_res->prob_blank = prob_blank;
}
for (int i = 0; i < static_cast<int>(num_classes) - 1; i++) {
auto extend = candidate_sentence;
extend.push_back(i);
if (candidate_sentence.size() > 0 && candidate.sentence.back() == i) {
prob_not_blank = prob[i] * candidate.prob_blank;
} else {
prob_not_blank = prob[i] * candidate.prob();
}
auto check_res2 = std::find_if(curr.begin(),
curr.end(),
[&extend](const BeamElement &n) {
return n.sentence == extend;
});
if (check_res2 == std::end(curr)) {
curr.push_back(BeamElement{extend, 0.f, prob_not_blank});
} else {
check_res2->prob_not_blank += prob_not_blank;
}
}
}
sort(curr.begin(), curr.end(), [](const BeamElement &a, const BeamElement &b) -> bool {
return a.prob() > b.prob();
});
last.clear();
int num_to_copy = std::min(bandwidth, static_cast<int>(curr.size()));
for (int b = 0; b < num_to_copy; b++) {
last.push_back(curr[b]);
}
}
*conf = last[0].prob();
std::string res="";
for (const auto& idx: last[0].sentence) {
res += alphabet[idx];
}
return res;
}
//////////////////////////////////////////////////////////////////////
} // anonymous namespace
namespace custom {
namespace {
//////////////////////////////////////////////////////////////////////
// Define networks for this sample
using GMat2 = std::tuple<cv::GMat, cv::GMat>;
G_API_NET(TextDetection,
<GMat2(cv::GMat)>,
"sample.custom.text_detect");
G_API_NET(TextRecognition,
<cv::GMat(cv::GMat)>,
"sample.custom.text_recogn");
// Define custom operations
using GSize = cv::GOpaque<cv::Size>;
using GRRects = cv::GArray<cv::RotatedRect>;
G_API_OP(PostProcess,
<GRRects(cv::GMat,cv::GMat,GSize,float,float)>,
"sample.custom.text.post_proc") {
static cv::GArrayDesc outMeta(const cv::GMatDesc &,
const cv::GMatDesc &,
const cv::GOpaqueDesc &,
float,
float) {
return cv::empty_array_desc();
}
};
using GMats = cv::GArray<cv::GMat>;
G_API_OP(CropLabels,
<GMats(cv::GMat,GRRects,GSize)>,
"sample.custom.text.crop") {
static cv::GArrayDesc outMeta(const cv::GMatDesc &,
const cv::GArrayDesc &,
const cv::GOpaqueDesc &) {
return cv::empty_array_desc();
}
};
//////////////////////////////////////////////////////////////////////
// Implement custom operations
GAPI_OCV_KERNEL(OCVPostProcess, PostProcess) {
static void run(const cv::Mat &link,
const cv::Mat &segm,
const cv::Size &img_size,
const float link_threshold,
const float segm_threshold,
std::vector<cv::RotatedRect> &out) {
// NOTE: Taken from the OMZ text detection sample almost as-is
const int kMinArea = 300;
const int kMinHeight = 10;
const float *link_data_pointer = link.ptr<float>();
std::vector<float> link_data(link_data_pointer, link_data_pointer + link.total());
link_data = transpose4d(link_data, dimsToShape(link.size), {0, 2, 3, 1});
softmax(link_data);
link_data = sliceAndGetSecondChannel(link_data);
std::vector<int> new_link_data_shape = {
link.size[0],
link.size[2],
link.size[3],
link.size[1]/2,
};
const float *cls_data_pointer = segm.ptr<float>();
std::vector<float> cls_data(cls_data_pointer, cls_data_pointer + segm.total());
cls_data = transpose4d(cls_data, dimsToShape(segm.size), {0, 2, 3, 1});
softmax(cls_data);
cls_data = sliceAndGetSecondChannel(cls_data);
std::vector<int> new_cls_data_shape = {
segm.size[0],
segm.size[2],
segm.size[3],
segm.size[1]/2,
};
out = maskToBoxes(decodeImageByJoin(cls_data, new_cls_data_shape,
link_data, new_link_data_shape,
segm_threshold, link_threshold),
static_cast<float>(kMinArea),
static_cast<float>(kMinHeight),
img_size);
}
static std::vector<std::size_t> dimsToShape(const cv::MatSize &sz) {
const int n_dims = sz.dims();
std::vector<std::size_t> result;
result.reserve(n_dims);
// cv::MatSize is not iterable...
for (int i = 0; i < n_dims; i++) {
result.emplace_back(static_cast<std::size_t>(sz[i]));
}
return result;
}
static void softmax(std::vector<float> &rdata) {
// NOTE: Taken from the OMZ text detection sample almost as-is
const size_t last_dim = 2;
for (size_t i = 0 ; i < rdata.size(); i+=last_dim) {
float m = std::max(rdata[i], rdata[i+1]);
rdata[i] = std::exp(rdata[i] - m);
rdata[i + 1] = std::exp(rdata[i + 1] - m);
float s = rdata[i] + rdata[i + 1];
rdata[i] /= s;
rdata[i + 1] /= s;
}
}
static std::vector<float> transpose4d(const std::vector<float> &data,
const std::vector<size_t> &shape,
const std::vector<size_t> &axes) {
// NOTE: Taken from the OMZ text detection sample almost as-is
if (shape.size() != axes.size())
throw std::runtime_error("Shape and axes must have the same dimension.");
for (size_t a : axes) {
if (a >= shape.size())
throw std::runtime_error("Axis must be less than dimension of shape.");
}
size_t total_size = shape[0]*shape[1]*shape[2]*shape[3];
std::vector<size_t> steps {
shape[axes[1]]*shape[axes[2]]*shape[axes[3]],
shape[axes[2]]*shape[axes[3]],
shape[axes[3]],
1
};
size_t source_data_idx = 0;
std::vector<float> new_data(total_size, 0);
std::vector<size_t> ids(shape.size());
for (ids[0] = 0; ids[0] < shape[0]; ids[0]++) {
for (ids[1] = 0; ids[1] < shape[1]; ids[1]++) {
for (ids[2] = 0; ids[2] < shape[2]; ids[2]++) {
for (ids[3]= 0; ids[3] < shape[3]; ids[3]++) {
size_t new_data_idx = ids[axes[0]]*steps[0] + ids[axes[1]]*steps[1] +
ids[axes[2]]*steps[2] + ids[axes[3]]*steps[3];
new_data[new_data_idx] = data[source_data_idx++];
}
}
}
}
return new_data;
}
static std::vector<float> sliceAndGetSecondChannel(const std::vector<float> &data) {
// NOTE: Taken from the OMZ text detection sample almost as-is
std::vector<float> new_data(data.size() / 2, 0);
for (size_t i = 0; i < data.size() / 2; i++) {
new_data[i] = data[2 * i + 1];
}
return new_data;
}
static void join(const int p1,
const int p2,
std::unordered_map<int, int> &group_mask) {
// NOTE: Taken from the OMZ text detection sample almost as-is
const int root1 = findRoot(p1, group_mask);
const int root2 = findRoot(p2, group_mask);
if (root1 != root2) {
group_mask[root1] = root2;
}
}
static cv::Mat decodeImageByJoin(const std::vector<float> &cls_data,
const std::vector<int> &cls_data_shape,
const std::vector<float> &link_data,
const std::vector<int> &link_data_shape,
float cls_conf_threshold,
float link_conf_threshold) {
// NOTE: Taken from the OMZ text detection sample almost as-is
const int h = cls_data_shape[1];
const int w = cls_data_shape[2];
std::vector<uchar> pixel_mask(h * w, 0);
std::unordered_map<int, int> group_mask;
std::vector<cv::Point> points;
for (int i = 0; i < static_cast<int>(pixel_mask.size()); i++) {
pixel_mask[i] = cls_data[i] >= cls_conf_threshold;
if (pixel_mask[i]) {
points.emplace_back(i % w, i / w);
group_mask[i] = -1;
}
}
std::vector<uchar> link_mask(link_data.size(), 0);
for (size_t i = 0; i < link_mask.size(); i++) {
link_mask[i] = link_data[i] >= link_conf_threshold;
}
size_t neighbours = size_t(link_data_shape[3]);
for (const auto &point : points) {
size_t neighbour = 0;
for (int ny = point.y - 1; ny <= point.y + 1; ny++) {
for (int nx = point.x - 1; nx <= point.x + 1; nx++) {
if (nx == point.x && ny == point.y)
continue;
if (nx >= 0 && nx < w && ny >= 0 && ny < h) {
uchar pixel_value = pixel_mask[size_t(ny) * size_t(w) + size_t(nx)];
uchar link_value = link_mask[(size_t(point.y) * size_t(w) + size_t(point.x))
*neighbours + neighbour];
if (pixel_value && link_value) {
join(point.x + point.y * w, nx + ny * w, group_mask);
}
}
neighbour++;
}
}
}
return get_all(points, w, h, group_mask);
}
static cv::Mat get_all(const std::vector<cv::Point> &points,
const int w,
const int h,
std::unordered_map<int, int> &group_mask) {
// NOTE: Taken from the OMZ text detection sample almost as-is
std::unordered_map<int, int> root_map;
cv::Mat mask(h, w, CV_32S, cv::Scalar(0));
for (const auto &point : points) {
int point_root = findRoot(point.x + point.y * w, group_mask);
if (root_map.find(point_root) == root_map.end()) {
root_map.emplace(point_root, static_cast<int>(root_map.size() + 1));
}
mask.at<int>(point.x + point.y * w) = root_map[point_root];
}
return mask;
}
static int findRoot(const int point,
std::unordered_map<int, int> &group_mask) {
// NOTE: Taken from the OMZ text detection sample almost as-is
int root = point;
bool update_parent = false;
while (group_mask.at(root) != -1) {
root = group_mask.at(root);
update_parent = true;
}
if (update_parent) {
group_mask[point] = root;
}
return root;
}
static std::vector<cv::RotatedRect> maskToBoxes(const cv::Mat &mask,
const float min_area,
const float min_height,
const cv::Size &image_size) {
// NOTE: Taken from the OMZ text detection sample almost as-is
std::vector<cv::RotatedRect> bboxes;
double min_val = 0.;
double max_val = 0.;
cv::minMaxLoc(mask, &min_val, &max_val);
int max_bbox_idx = static_cast<int>(max_val);
cv::Mat resized_mask;
cv::resize(mask, resized_mask, image_size, 0, 0, cv::INTER_NEAREST);
for (int i = 1; i <= max_bbox_idx; i++) {
cv::Mat bbox_mask = resized_mask == i;
std::vector<std::vector<cv::Point>> contours;
cv::findContours(bbox_mask, contours, cv::RETR_CCOMP, cv::CHAIN_APPROX_SIMPLE);
if (contours.empty())
continue;
cv::RotatedRect r = cv::minAreaRect(contours[0]);
if (std::min(r.size.width, r.size.height) < min_height)
continue;
if (r.size.area() < min_area)
continue;
bboxes.emplace_back(r);
}
return bboxes;
}
}; // GAPI_OCV_KERNEL(PostProcess)
GAPI_OCV_KERNEL(OCVCropLabels, CropLabels) {
static void run(const cv::Mat &image,
const std::vector<cv::RotatedRect> &detections,
const cv::Size &outSize,
std::vector<cv::Mat> &out) {
out.clear();
out.reserve(detections.size());
cv::Mat crop(outSize, CV_8UC3, cv::Scalar(0));
cv::Mat gray(outSize, CV_8UC1, cv::Scalar(0));
std::vector<int> blob_shape = {1,1,outSize.height,outSize.width};
for (auto &&rr : detections) {
std::vector<cv::Point2f> points(4);
rr.points(points.data());
const auto top_left_point_idx = topLeftPointIdx(points);
cv::Point2f point0 = points[static_cast<size_t>(top_left_point_idx)];
cv::Point2f point1 = points[(top_left_point_idx + 1) % 4];
cv::Point2f point2 = points[(top_left_point_idx + 2) % 4];
std::vector<cv::Point2f> from{point0, point1, point2};
std::vector<cv::Point2f> to{
cv::Point2f(0.0f, 0.0f),
cv::Point2f(static_cast<float>(outSize.width-1), 0.0f),
cv::Point2f(static_cast<float>(outSize.width-1),
static_cast<float>(outSize.height-1))
};
cv::Mat M = cv::getAffineTransform(from, to);
cv::warpAffine(image, crop, M, outSize);
cv::cvtColor(crop, gray, cv::COLOR_BGR2GRAY);
cv::Mat blob;
gray.convertTo(blob, CV_32F);
out.push_back(blob.reshape(1, blob_shape)); // pass as 1,1,H,W instead of H,W
}
}
static int topLeftPointIdx(const std::vector<cv::Point2f> &points) {
// NOTE: Taken from the OMZ text detection sample almost as-is
cv::Point2f most_left(std::numeric_limits<float>::max(),
std::numeric_limits<float>::max());
cv::Point2f almost_most_left(std::numeric_limits<float>::max(),
std::numeric_limits<float>::max());
int most_left_idx = -1;
int almost_most_left_idx = -1;
for (size_t i = 0; i < points.size() ; i++) {
if (most_left.x > points[i].x) {
if (most_left.x < std::numeric_limits<float>::max()) {
almost_most_left = most_left;
almost_most_left_idx = most_left_idx;
}
most_left = points[i];
most_left_idx = static_cast<int>(i);
}
if (almost_most_left.x > points[i].x && points[i] != most_left) {
almost_most_left = points[i];
almost_most_left_idx = static_cast<int>(i);
}
}
if (almost_most_left.y < most_left.y) {
most_left = almost_most_left;
most_left_idx = almost_most_left_idx;
}
return most_left_idx;
}
}; // GAPI_OCV_KERNEL(CropLabels)
} // anonymous namespace
} // namespace custom
namespace vis {
namespace {
void drawRotatedRect(cv::Mat &m, const cv::RotatedRect &rc) {
std::vector<cv::Point2f> tmp_points(5);
rc.points(tmp_points.data());
tmp_points[4] = tmp_points[0];
auto prev = tmp_points.begin(), it = prev+1;
for (; it != tmp_points.end(); ++it) {
cv::line(m, *prev, *it, cv::Scalar(50, 205, 50), 2);
prev = it;
}
}
void drawText(cv::Mat &m, const cv::RotatedRect &rc, const std::string &str) {
const int fface = cv::FONT_HERSHEY_SIMPLEX;
const double scale = 0.7;
const int thick = 1;
int base = 0;
const auto text_size = cv::getTextSize(str, fface, scale, thick, &base);
std::vector<cv::Point2f> tmp_points(4);
rc.points(tmp_points.data());
const auto tl_point_idx = custom::OCVCropLabels::topLeftPointIdx(tmp_points);
cv::Point text_pos = tmp_points[tl_point_idx];
text_pos.x = std::max(0, text_pos.x);
text_pos.y = std::max(text_size.height, text_pos.y);
cv::rectangle(m,
text_pos + cv::Point{0, base},
text_pos + cv::Point{text_size.width, -text_size.height},
CV_RGB(50, 205, 50),
cv::FILLED);
const auto white = CV_RGB(255, 255, 255);
cv::putText(m, str, text_pos, fface, scale, white, thick, 8);
}
} // anonymous namespace
} // namespace vis
int main(int argc, char *argv[])
{
cv::CommandLineParser cmd(argc, argv, keys);
cmd.about(about);
if (cmd.has("help")) {
cmd.printMessage();
return 0;
}
const auto input_file_name = cmd.get<std::string>("input");
const auto tdet_model_path = cmd.get<std::string>("tdm");
const auto trec_model_path = cmd.get<std::string>("trm");
const auto tdet_target_dev = cmd.get<std::string>("tdd");
const auto trec_target_dev = cmd.get<std::string>("trd");
const auto ctc_beam_dec_bw = cmd.get<int>("bw");
const auto dec_conf_thresh = cmd.get<double>("thr");
const auto pad_symbol = '#';
const auto symbol_set = cmd.get<std::string>("sset") + pad_symbol;
cv::GMat in;
cv::GOpaque<cv::Size> in_rec_sz;
cv::GMat link, segm;
std::tie(link, segm) = cv::gapi::infer<custom::TextDetection>(in);
cv::GOpaque<cv::Size> size = cv::gapi::streaming::size(in);
cv::GArray<cv::RotatedRect> rrs = custom::PostProcess::on(link, segm, size, 0.8f, 0.8f);
cv::GArray<cv::GMat> labels = custom::CropLabels::on(in, rrs, in_rec_sz);
cv::GArray<cv::GMat> text = cv::gapi::infer2<custom::TextRecognition>(in, labels);
cv::GComputation graph(cv::GIn(in, in_rec_sz),
cv::GOut(cv::gapi::copy(in), rrs, text));
// Text detection network
auto tdet_net = cv::gapi::ie::Params<custom::TextDetection> {
tdet_model_path, // path to topology IR
weights_path(tdet_model_path), // path to weights
tdet_target_dev, // device specifier
}.cfgOutputLayers({"model/link_logits_/add", "model/segm_logits/add"});
auto trec_net = cv::gapi::ie::Params<custom::TextRecognition> {
trec_model_path, // path to topology IR
weights_path(trec_model_path), // path to weights
trec_target_dev, // device specifier
};
auto networks = cv::gapi::networks(tdet_net, trec_net);
auto kernels = cv::gapi::kernels< custom::OCVPostProcess
, custom::OCVCropLabels
>();
auto pipeline = graph.compileStreaming(cv::compile_args(kernels, networks));
std::cout << "Reading " << input_file_name << std::endl;
// Input stream
auto in_src = cv::gapi::wip::make_src<cv::gapi::wip::GCaptureSource>(input_file_name);
// Text recognition input size (also an input parameter to the graph)
auto in_rsz = cv::Size{ 120, 32 };
// Set the pipeline source & start the pipeline
pipeline.setSource(cv::gin(in_src, in_rsz));
pipeline.start();
// Declare the output data & run the processing loop
cv::TickMeter tm;
cv::Mat image;
std::vector<cv::RotatedRect> out_rcs;
std::vector<cv::Mat> out_text;
tm.start();
int frames = 0;
while (pipeline.pull(cv::gout(image, out_rcs, out_text))) {
frames++;
CV_Assert(out_rcs.size() == out_text.size());
const auto num_labels = out_rcs.size();
std::vector<cv::Point2f> tmp_points(4);
for (std::size_t l = 0; l < num_labels; l++) {
// Decode the recognized text in the rectangle
const auto &blob = out_text[l];
const float *data = blob.ptr<float>();
const auto sz = blob.total();
double conf = 1.0;
const std::string res = ctc_beam_dec_bw == 0
? CTCGreedyDecoder(data, sz, symbol_set, pad_symbol, &conf)
: CTCBeamSearchDecoder(data, sz, symbol_set, &conf, ctc_beam_dec_bw);
// Draw a bounding box for this rotated rectangle
const auto &rc = out_rcs[l];
vis::drawRotatedRect(image, rc);
// Draw text, if decoded
if (conf >= dec_conf_thresh) {
vis::drawText(image, rc, res);
}
}
tm.stop();
cv::imshow("Out", image);
cv::waitKey(1);
tm.start();
}
tm.stop();
std::cout << "Processed " << frames << " frames"
<< " (" << frames / tm.getTimeSec() << " FPS)" << std::endl;
return 0;
}