Method decodeMaskedAreas

src/librawspeed/decoders/DngDecoder.cpp:637–675

Decodes DNG masked areas into blackareas in the image */

/* Decodes DNG masked areas into blackareas in the image */
bool DngDecoder::decodeMaskedAreas(const TiffIFD* raw) {
  TiffEntry *masked = raw->getEntry(MASKEDAREAS);

  if (masked->type != TIFF_SHORT && masked->type != TIFF_LONG)
    return false;

  uint32_t nrects = masked->count / 4;
  if (0 == nrects)
    return false;

  /* Since we may both have short or int, copy it to int array. */
  auto rects = masked->getU32Array(nrects*4);

  const iRectangle2D fullImage(0, 0, mRaw->getUncroppedDim().x,
                               mRaw->getUncroppedDim().y);
  const iPoint2D top = mRaw->getCropOffset();

  for (uint32_t i = 0; i < nrects; i++) {
    iPoint2D topleft = iPoint2D(rects[i * 4UL + 1UL], rects[i * 4UL]);
    iPoint2D bottomright = iPoint2D(rects[i * 4UL + 3UL], rects[i * 4UL + 2UL]);

    if (!(fullImage.isPointInsideInclusive(topleft) &&
          fullImage.isPointInsideInclusive(bottomright) &&
          (topleft < bottomright)))
      ThrowRDE("Bad masked area.");

    // Is this a horizontal box, only add it if it covers the active width of the image
    if (topleft.x <= top.x && bottomright.x >= (mRaw->dim.x + top.x)) {
      mRaw->blackAreas.emplace_back(topleft.y, bottomright.y - topleft.y,
                                    false);
    }
    // Is it a vertical box, only add it if it covers the active height of the
    // image
    else if (topleft.y <= top.y && bottomright.y >= (mRaw->dim.y + top.y)) {
      mRaw->blackAreas.emplace_back(topleft.x, bottomright.x - topleft.x, true);
    }
  }
  return !mRaw->blackAreas.empty();
}

bool DngDecoder::decodeBlackLevels(const TiffIFD* raw) {
  iPoint2D blackdim(1,1);