Method Crop

deps/tesseract/cube/bmp_8.cpp:318–359

crop the bitmap returning new dimensions

// crop the bitmap returning new dimensions
void Bmp8::Crop(int *xst, int *yst, int *wid, int *hgt) {
  (*xst) = 0;
  (*yst) = 0;

  int xend = wid_ - 1;
  int yend = hgt_ - 1;

  while ((*xst) < (wid_ - 1) && (*xst) <= xend) {
    // column is not empty
    if (!IsBlankColumn((*xst))) {
      break;
    }
    (*xst)++;
  }

  while (xend > 0 && xend >= (*xst)) {
    // column is not empty
    if (!IsBlankColumn(xend)) {
      break;
    }
    xend--;
  }

  while ((*yst) < (hgt_ - 1) && (*yst) <= yend) {
    // column is not empty
    if (!IsBlankRow((*yst))) {
      break;
    }
    (*yst)++;
  }

  while (yend > 0 && yend >= (*yst)) {
    // column is not empty
    if (!IsBlankRow(yend)) {
      break;
    }
    yend--;
  }

  (*wid) = xend - (*xst) + 1;
  (*hgt) = yend - (*yst) + 1;
}

// generates a scaled bitmap with dimensions the new bmp will have the
// same aspect ratio and will be centered in the box