Quad Refine::operator()(
const cv::Mat &inputImage,
const Quad &quad,
const float proximityRatio)
{
cv::Mat_<cv::Point2f> refinedQuad(quad);
// Taking a ROI around the raw corners with some margin
static const float GROWTH_RATIO = 1.2f/10.0f;
cv::Rect roi = chilitags::growRoi(inputImage, refinedQuad, GROWTH_RATIO);
static const int MIN_ROI_SIZE = 10;
if (roi.width < MIN_ROI_SIZE || roi.height < MIN_ROI_SIZE) return quad;
cv::Point2f roiOffset = roi.tl();
for (int i : {0,1,2,3}) refinedQuad(i) -= roiOffset;
float averageSideLength = cv::arcLength(refinedQuad, true) / 4.0f;
float cornerNeighbourhood = proximityRatio*averageSideLength;
// ensure the cornerSubPixel search window is smaller that the ROI
cornerNeighbourhood = cv::min(cornerNeighbourhood, (roi.width - 5.0f)/2.0f);
cornerNeighbourhood = cv::min(cornerNeighbourhood, (roi.height - 5.0f)/2.0f);
cornerNeighbourhood = cv::max(cornerNeighbourhood, 1.0f);
cv::cornerSubPix(inputImage(roi), refinedQuad,
cv::Size(cornerNeighbourhood, cornerNeighbourhood),
cv::Size(-1, -1), cv::TermCriteria(
cv::TermCriteria::MAX_ITER + cv::TermCriteria::EPS,
5, 0.01f));
#ifdef DEBUG_Refine
cv::Mat debugImage = inputImage(roi).clone();
for(int i=0; i<4; ++i)
{
cv::circle(debugImage, refinedQuad(i), 3, cv::Scalar::all(128), 2);
cv::line(debugImage,
refinedQuad(i), refinedQuad(i),
cv::Scalar::all(255), 5);
cv::rectangle(debugImage,
refinedQuad(i)-cv::Point2f(cornerNeighbourhood, cornerNeighbourhood), refinedQuad(i)+cv::Point2f(cornerNeighbourhood, cornerNeighbourhood),
cv::Scalar::all(255));
printf("%1.1f %1.1f ", refinedQuad(i).x, refinedQuad(i).y);
}
printf("\n");
cv::imshow("Refine", debugImage);
cv::waitKey(0);
#endif
for (int i : {0,1,2,3}) refinedQuad(i) += roiOffset;
return refinedQuad.reshape(1);
}
chilitags::Quad chilitags::Refine::operator()(const cv::Mat &inputImage, const Quad &quad)
{
cv::Mat_<cv::Point2f> refinedQuad(quad);
// Taking a ROI around the raw corners with some margin
static const float GROWTH_RATIO = 1.2f/10.0f;
cv::Rect roi = cv::boundingRect(refinedQuad);
int xGrowth = (int)(GROWTH_RATIO*roi.width);
int yGrowth = (int)(GROWTH_RATIO*roi.height);
roi.x -= xGrowth;
roi.y -= yGrowth;
roi.width += 2*xGrowth;
roi.height += 2*yGrowth;
// Making sure the ROI is still in the image
int previousRoiX = roi.x;
int previousRoiY = roi.y;
roi.x = std::max(roi.x, 0);
roi.y = std::max(roi.y, 0);
roi.width -= roi.x - previousRoiX;
roi.height -= roi.y - previousRoiY;
roi.width = cv::min(roi.x+roi.width, inputImage.cols)-roi.x;
roi.height = cv::min(roi.y+roi.height, inputImage.rows)-roi.y;
static const int MIN_ROI_SIZE = 10;
if (roi.width < MIN_ROI_SIZE || roi.height < MIN_ROI_SIZE) return quad;
cv::Point2f roiOffset = roi.tl();
for (int i : {0,1,2,3}) refinedQuad(i) -= roiOffset;
static const double PROXIMITYRATIO = 1.5/10.0;
double averageSideLength = cv::arcLength(refinedQuad, true) / 4.0;
double cornerNeighbourhood = PROXIMITYRATIO*averageSideLength;
// ensure the cornerSubPixel search window is smaller that the ROI
cornerNeighbourhood = cv::min(cornerNeighbourhood, ((double) roi.width-5)/2);
cornerNeighbourhood = cv::min(cornerNeighbourhood, ((double) roi.height-5)/2);
cv::cornerSubPix(inputImage(roi), refinedQuad,
cv::Size(cornerNeighbourhood, cornerNeighbourhood),
cv::Size(-1, -1), cv::TermCriteria(
cv::TermCriteria::MAX_ITER + cv::TermCriteria::EPS,
5, 0.01));
for (int i : {0,1,2,3}) refinedQuad(i) += roiOffset;
#ifdef DEBUG_Refine
cv::Mat debugImage = inputImage(roi).clone();
for(int i=0; i<4; ++i)
{
cv::circle(debugImage, refinedQuad(i)-roiOffset,
3, cv::Scalar::all(128), 2);
cv::line(debugImage,
refinedQuad(i)-roiOffset, refinedQuad(i)-roiOffset,
cv::Scalar::all(255), 5);
cv::rectangle(debugImage,
refinedQuad(i)-roiOffset-cv::Point2f(cornerNeighbourhood, cornerNeighbourhood), refinedQuad(i)-roiOffset+cv::Point2f(cornerNeighbourhood, cornerNeighbourhood),
cv::Scalar::all(255));
printf("%1.1f %1.1f ", refinedQuad(i).x, refinedQuad(i).y);
}
printf("\n");
cv::imshow("Refine", debugImage);
cv::waitKey(0);
#endif
// Sometimes, the corners are refined into a concave quadrilateral
// which makes ReadBits crash
cv::Mat convexHull;
cv::convexHull(refinedQuad, convexHull, false);
if (convexHull.rows == 4) return convexHull.reshape(1);
return quad;
}
