pRawx   = pData->pWorkrow + 1; pPriorx = pData->pPrevrow + 1;
pRawx   = pData->pWorkrow + pData->iPixelofs; pPriorx = pData->pPrevrow + pData->iPixelofs;
mng_retcode filter_up (mng_datap pData){  mng_uint8p pRawx;  mng_uint8p pPriorx;  mng_int32  iX;#ifdef MNG_SUPPORT_TRACE  MNG_TRACE (pData, MNG_FN_FILTER_UP, MNG_LC_START)#endif  pRawx   = pData->pWorkrow + 1;  pPriorx = pData->pPrevrow + 1;  for (iX = 0; iX < pData->iRowsize; iX++)  {    pRawx [0] = (mng_uint8)(pRawx [0] + pPriorx [0]);    pRawx++;    pPriorx++;  }#ifdef MNG_SUPPORT_TRACE  MNG_TRACE (pData, MNG_FN_FILTER_UP, MNG_LC_END)#endif  return MNG_NOERROR;}