Method ClassifyNormalizeIfNeeded

deps/tesseract/ccstruct/blobs.cpp:363–383

Normalizes the blob for classification only if needed. (Normally this means a non-zero classify rotation.) If no Normalization is needed, then NULL is returned, and the input blob can be used directly. Otherwise a new TBLOB is returned which must be deleted after use.

// can be used directly. Otherwise a new TBLOB is returned which must be
// deleted after use.
TBLOB* TBLOB::ClassifyNormalizeIfNeeded() const {
  TBLOB* rotated_blob = NULL;
  // If necessary, copy the blob and rotate it. The rotation is always
  // +/- 90 degrees, as 180 was already taken care of.
  if (denorm_.block() != NULL &&
      denorm_.block()->classify_rotation().y() != 0.0) {
    TBOX box = bounding_box();
    int x_middle = (box.left() + box.right()) / 2;
    int y_middle = (box.top() + box.bottom()) / 2;
    rotated_blob = new TBLOB(*this);
    const FCOORD& rotation = denorm_.block()->classify_rotation();
    // Move the rotated blob back to the same y-position so that we
    // can still distinguish similar glyphs with differeny y-position.
    float target_y = kBlnBaselineOffset +
        (rotation.y() > 0 ? x_middle - box.left() : box.right() - x_middle);
    rotated_blob->Normalize(NULL, &rotation, &denorm_, x_middle, y_middle,
                            1.0f, 1.0f, 0.0f, target_y,
                            denorm_.inverse(), denorm_.pix());
  }
  return rotated_blob;
}

// Copies the data and the outline, but leaves next untouched.
void TBLOB::CopyFrom(const TBLOB& src) {