cart-elc

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TensorImagePatch.h (28066B)


      1 // This file is part of Eigen, a lightweight C++ template library
      2 // for linear algebra.
      3 //
      4 // Copyright (C) 2014 Benoit Steiner <benoit.steiner.goog@gmail.com>
      5 //
      6 // This Source Code Form is subject to the terms of the Mozilla
      7 // Public License v. 2.0. If a copy of the MPL was not distributed
      8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
      9 
     10 #ifndef EIGEN_CXX11_TENSOR_TENSOR_IMAGE_PATCH_H
     11 #define EIGEN_CXX11_TENSOR_TENSOR_IMAGE_PATCH_H
     12 
     13 namespace Eigen {
     14 
     15 /** \class TensorImagePatch
     16   * \ingroup CXX11_Tensor_Module
     17   *
     18   * \brief Patch extraction specialized for image processing.
     19   * This assumes that the input has a least 3 dimensions ordered as follow:
     20   *  1st dimension: channels (of size d)
     21   *  2nd dimension: rows (of size r)
     22   *  3rd dimension: columns (of size c)
     23   *  There can be additional dimensions such as time (for video) or batch (for
     24   * bulk processing after the first 3.
     25   * Calling the image patch code with patch_rows and patch_cols is equivalent
     26   * to calling the regular patch extraction code with parameters d, patch_rows,
     27   * patch_cols, and 1 for all the additional dimensions.
     28   */
     29 namespace internal {
     30 
     31 template<DenseIndex Rows, DenseIndex Cols, typename XprType>
     32 struct traits<TensorImagePatchOp<Rows, Cols, XprType> > : public traits<XprType>
     33 {
     34   typedef typename internal::remove_const<typename XprType::Scalar>::type Scalar;
     35   typedef traits<XprType> XprTraits;
     36   typedef typename XprTraits::StorageKind StorageKind;
     37   typedef typename XprTraits::Index Index;
     38   typedef typename XprType::Nested Nested;
     39   typedef typename remove_reference<Nested>::type _Nested;
     40   static const int NumDimensions = XprTraits::NumDimensions + 1;
     41   static const int Layout = XprTraits::Layout;
     42   typedef typename XprTraits::PointerType PointerType;
     43 };
     44 
     45 template<DenseIndex Rows, DenseIndex Cols, typename XprType>
     46 struct eval<TensorImagePatchOp<Rows, Cols, XprType>, Eigen::Dense>
     47 {
     48   typedef const TensorImagePatchOp<Rows, Cols, XprType>& type;
     49 };
     50 
     51 template<DenseIndex Rows, DenseIndex Cols, typename XprType>
     52 struct nested<TensorImagePatchOp<Rows, Cols, XprType>, 1, typename eval<TensorImagePatchOp<Rows, Cols, XprType> >::type>
     53 {
     54   typedef TensorImagePatchOp<Rows, Cols, XprType> type;
     55 };
     56 
     57 template <typename Self, bool Vectorizable>
     58 struct ImagePatchCopyOp {
     59   typedef typename Self::Index Index;
     60   typedef typename Self::Scalar Scalar;
     61   typedef typename Self::Impl Impl;
     62   static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void Run(
     63       const Self& self, const Index num_coeff_to_copy, const Index dst_index,
     64       Scalar* dst_data, const Index src_index) {
     65     const Impl& impl = self.impl();
     66     for (Index i = 0; i < num_coeff_to_copy; ++i) {
     67       dst_data[dst_index + i] = impl.coeff(src_index + i);
     68     }
     69   }
     70 };
     71 
     72 template <typename Self>
     73 struct ImagePatchCopyOp<Self, true> {
     74   typedef typename Self::Index Index;
     75   typedef typename Self::Scalar Scalar;
     76   typedef typename Self::Impl Impl;
     77   typedef typename packet_traits<Scalar>::type Packet;
     78   static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void Run(
     79       const Self& self, const Index num_coeff_to_copy, const Index dst_index,
     80       Scalar* dst_data, const Index src_index) {
     81     const Impl& impl = self.impl();
     82     const Index packet_size = internal::unpacket_traits<Packet>::size;
     83     const Index vectorized_size =
     84         (num_coeff_to_copy / packet_size) * packet_size;
     85     for (Index i = 0; i < vectorized_size; i += packet_size) {
     86       Packet p = impl.template packet<Unaligned>(src_index + i);
     87       internal::pstoret<Scalar, Packet, Unaligned>(dst_data + dst_index + i, p);
     88     }
     89     for (Index i = vectorized_size; i < num_coeff_to_copy; ++i) {
     90       dst_data[dst_index + i] = impl.coeff(src_index + i);
     91     }
     92   }
     93 };
     94 
     95 template <typename Self>
     96 struct ImagePatchPaddingOp {
     97   typedef typename Self::Index Index;
     98   typedef typename Self::Scalar Scalar;
     99   typedef typename packet_traits<Scalar>::type Packet;
    100   static EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void Run(
    101       const Index num_coeff_to_pad, const Scalar padding_value,
    102       const Index dst_index, Scalar* dst_data) {
    103     const Index packet_size = internal::unpacket_traits<Packet>::size;
    104     const Packet padded_packet = internal::pset1<Packet>(padding_value);
    105     const Index vectorized_size =
    106         (num_coeff_to_pad / packet_size) * packet_size;
    107     for (Index i = 0; i < vectorized_size; i += packet_size) {
    108       internal::pstoret<Scalar, Packet, Unaligned>(dst_data + dst_index + i,
    109                                                    padded_packet);
    110     }
    111     for (Index i = vectorized_size; i < num_coeff_to_pad; ++i) {
    112       dst_data[dst_index + i] = padding_value;
    113     }
    114   }
    115 };
    116 
    117 }  // end namespace internal
    118 
    119 template<DenseIndex Rows, DenseIndex Cols, typename XprType>
    120 class TensorImagePatchOp : public TensorBase<TensorImagePatchOp<Rows, Cols, XprType>, ReadOnlyAccessors>
    121 {
    122   public:
    123   typedef typename Eigen::internal::traits<TensorImagePatchOp>::Scalar Scalar;
    124   typedef typename Eigen::NumTraits<Scalar>::Real RealScalar;
    125   typedef typename XprType::CoeffReturnType CoeffReturnType;
    126   typedef typename Eigen::internal::nested<TensorImagePatchOp>::type Nested;
    127   typedef typename Eigen::internal::traits<TensorImagePatchOp>::StorageKind StorageKind;
    128   typedef typename Eigen::internal::traits<TensorImagePatchOp>::Index Index;
    129 
    130   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE TensorImagePatchOp(const XprType& expr, DenseIndex patch_rows, DenseIndex patch_cols,
    131                                                            DenseIndex row_strides, DenseIndex col_strides,
    132                                                            DenseIndex in_row_strides, DenseIndex in_col_strides,
    133                                                            DenseIndex row_inflate_strides, DenseIndex col_inflate_strides,
    134                                                            PaddingType padding_type, Scalar padding_value)
    135                                                            : m_xpr(expr), m_patch_rows(patch_rows), m_patch_cols(patch_cols),
    136                                                            m_row_strides(row_strides), m_col_strides(col_strides),
    137                                                            m_in_row_strides(in_row_strides), m_in_col_strides(in_col_strides),
    138                                                            m_row_inflate_strides(row_inflate_strides), m_col_inflate_strides(col_inflate_strides),
    139                                                            m_padding_explicit(false), m_padding_top(0), m_padding_bottom(0), m_padding_left(0), m_padding_right(0),
    140                                                            m_padding_type(padding_type), m_padding_value(padding_value) {}
    141 
    142   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE TensorImagePatchOp(const XprType& expr, DenseIndex patch_rows, DenseIndex patch_cols,
    143                                                            DenseIndex row_strides, DenseIndex col_strides,
    144                                                            DenseIndex in_row_strides, DenseIndex in_col_strides,
    145                                                            DenseIndex row_inflate_strides, DenseIndex col_inflate_strides,
    146                                                            DenseIndex padding_top, DenseIndex padding_bottom,
    147                                                            DenseIndex padding_left, DenseIndex padding_right,
    148                                                            Scalar padding_value)
    149                                                            : m_xpr(expr), m_patch_rows(patch_rows), m_patch_cols(patch_cols),
    150                                                            m_row_strides(row_strides), m_col_strides(col_strides),
    151                                                            m_in_row_strides(in_row_strides), m_in_col_strides(in_col_strides),
    152                                                            m_row_inflate_strides(row_inflate_strides), m_col_inflate_strides(col_inflate_strides),
    153                                                            m_padding_explicit(true), m_padding_top(padding_top), m_padding_bottom(padding_bottom),
    154                                                            m_padding_left(padding_left), m_padding_right(padding_right),
    155                                                            m_padding_type(PADDING_VALID), m_padding_value(padding_value) {}
    156 
    157 
    158     EIGEN_DEVICE_FUNC
    159     DenseIndex patch_rows() const { return m_patch_rows; }
    160     EIGEN_DEVICE_FUNC
    161     DenseIndex patch_cols() const { return m_patch_cols; }
    162     EIGEN_DEVICE_FUNC
    163     DenseIndex row_strides() const { return m_row_strides; }
    164     EIGEN_DEVICE_FUNC
    165     DenseIndex col_strides() const { return m_col_strides; }
    166     EIGEN_DEVICE_FUNC
    167     DenseIndex in_row_strides() const { return m_in_row_strides; }
    168     EIGEN_DEVICE_FUNC
    169     DenseIndex in_col_strides() const { return m_in_col_strides; }
    170     EIGEN_DEVICE_FUNC
    171     DenseIndex row_inflate_strides() const { return m_row_inflate_strides; }
    172     EIGEN_DEVICE_FUNC
    173     DenseIndex col_inflate_strides() const { return m_col_inflate_strides; }
    174     EIGEN_DEVICE_FUNC
    175     bool padding_explicit() const { return m_padding_explicit; }
    176     EIGEN_DEVICE_FUNC
    177     DenseIndex padding_top() const { return m_padding_top; }
    178     EIGEN_DEVICE_FUNC
    179     DenseIndex padding_bottom() const { return m_padding_bottom; }
    180     EIGEN_DEVICE_FUNC
    181     DenseIndex padding_left() const { return m_padding_left; }
    182     EIGEN_DEVICE_FUNC
    183     DenseIndex padding_right() const { return m_padding_right; }
    184     EIGEN_DEVICE_FUNC
    185     PaddingType padding_type() const { return m_padding_type; }
    186     EIGEN_DEVICE_FUNC
    187     Scalar padding_value() const { return m_padding_value; }
    188 
    189     EIGEN_DEVICE_FUNC
    190     const typename internal::remove_all<typename XprType::Nested>::type&
    191     expression() const { return m_xpr; }
    192 
    193   protected:
    194     typename XprType::Nested m_xpr;
    195     const DenseIndex m_patch_rows;
    196     const DenseIndex m_patch_cols;
    197     const DenseIndex m_row_strides;
    198     const DenseIndex m_col_strides;
    199     const DenseIndex m_in_row_strides;
    200     const DenseIndex m_in_col_strides;
    201     const DenseIndex m_row_inflate_strides;
    202     const DenseIndex m_col_inflate_strides;
    203     const bool m_padding_explicit;
    204     const DenseIndex m_padding_top;
    205     const DenseIndex m_padding_bottom;
    206     const DenseIndex m_padding_left;
    207     const DenseIndex m_padding_right;
    208     const PaddingType m_padding_type;
    209     const Scalar m_padding_value;
    210 };
    211 
    212 // Eval as rvalue
    213 template<DenseIndex Rows, DenseIndex Cols, typename ArgType, typename Device>
    214 struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
    215 {
    216   typedef TensorImagePatchOp<Rows, Cols, ArgType> XprType;
    217   typedef typename XprType::Index Index;
    218   static const int NumInputDims = internal::array_size<typename TensorEvaluator<ArgType, Device>::Dimensions>::value;
    219   static const int NumDims = NumInputDims + 1;
    220   typedef DSizes<Index, NumDims> Dimensions;
    221   typedef typename internal::remove_const<typename XprType::Scalar>::type Scalar;
    222   typedef TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>,
    223                           Device> Self;
    224   typedef TensorEvaluator<ArgType, Device> Impl;
    225   typedef typename XprType::CoeffReturnType CoeffReturnType;
    226   typedef typename PacketType<CoeffReturnType, Device>::type PacketReturnType;
    227   static const int PacketSize = PacketType<CoeffReturnType, Device>::size;
    228   typedef StorageMemory<CoeffReturnType, Device> Storage;
    229   typedef typename Storage::Type EvaluatorPointerType;
    230 
    231   enum {
    232     IsAligned         = false,
    233     PacketAccess      = TensorEvaluator<ArgType, Device>::PacketAccess,
    234     BlockAccess       = false,
    235     PreferBlockAccess = true,
    236     Layout            = TensorEvaluator<ArgType, Device>::Layout,
    237     CoordAccess       = false,
    238     RawAccess         = false
    239   };
    240 
    241   //===- Tensor block evaluation strategy (see TensorBlock.h) -------------===//
    242   typedef internal::TensorBlockNotImplemented TensorBlock;
    243   //===--------------------------------------------------------------------===//
    244 
    245   EIGEN_STRONG_INLINE TensorEvaluator( const XprType& op, const Device& device)
    246       : m_device(device), m_impl(op.expression(), device)
    247   {
    248     EIGEN_STATIC_ASSERT((NumDims >= 4), YOU_MADE_A_PROGRAMMING_MISTAKE);
    249 
    250     m_paddingValue = op.padding_value();
    251 
    252     const typename TensorEvaluator<ArgType, Device>::Dimensions& input_dims = m_impl.dimensions();
    253 
    254     // Caches a few variables.
    255     if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
    256       m_inputDepth = input_dims[0];
    257       m_inputRows = input_dims[1];
    258       m_inputCols = input_dims[2];
    259     } else {
    260       m_inputDepth = input_dims[NumInputDims-1];
    261       m_inputRows = input_dims[NumInputDims-2];
    262       m_inputCols = input_dims[NumInputDims-3];
    263     }
    264 
    265     m_row_strides = op.row_strides();
    266     m_col_strides = op.col_strides();
    267 
    268     // Input strides and effective input/patch size
    269     m_in_row_strides = op.in_row_strides();
    270     m_in_col_strides = op.in_col_strides();
    271     m_row_inflate_strides = op.row_inflate_strides();
    272     m_col_inflate_strides = op.col_inflate_strides();
    273     // The "effective" input rows and input cols are the input rows and cols
    274     // after inflating them with zeros.
    275     // For examples, a 2x3 matrix with row_inflate_strides and
    276     // col_inflate_strides of 2 comes from:
    277     //   A B C
    278     //   D E F
    279     //
    280     // to a matrix is 3 x 5:
    281     //
    282     //   A . B . C
    283     //   . . . . .
    284     //   D . E . F
    285 
    286     m_input_rows_eff = (m_inputRows - 1) * m_row_inflate_strides + 1;
    287     m_input_cols_eff = (m_inputCols - 1) * m_col_inflate_strides + 1;
    288     m_patch_rows_eff = op.patch_rows() + (op.patch_rows() - 1) * (m_in_row_strides - 1);
    289     m_patch_cols_eff = op.patch_cols() + (op.patch_cols() - 1) * (m_in_col_strides - 1);
    290 
    291     if (op.padding_explicit()) {
    292       m_outputRows = numext::ceil((m_input_rows_eff + op.padding_top() + op.padding_bottom() - m_patch_rows_eff + 1.f) / static_cast<float>(m_row_strides));
    293       m_outputCols = numext::ceil((m_input_cols_eff + op.padding_left() + op.padding_right() - m_patch_cols_eff + 1.f) / static_cast<float>(m_col_strides));
    294       m_rowPaddingTop = op.padding_top();
    295       m_colPaddingLeft = op.padding_left();
    296     } else {
    297       // Computing padding from the type
    298       switch (op.padding_type()) {
    299         case PADDING_VALID:
    300           m_outputRows = numext::ceil((m_input_rows_eff - m_patch_rows_eff + 1.f) / static_cast<float>(m_row_strides));
    301           m_outputCols = numext::ceil((m_input_cols_eff - m_patch_cols_eff + 1.f) / static_cast<float>(m_col_strides));
    302           // Calculate the padding
    303           m_rowPaddingTop = numext::maxi<Index>(0, ((m_outputRows - 1) * m_row_strides + m_patch_rows_eff - m_input_rows_eff) / 2);
    304           m_colPaddingLeft = numext::maxi<Index>(0, ((m_outputCols - 1) * m_col_strides + m_patch_cols_eff - m_input_cols_eff) / 2);
    305           break;
    306         case PADDING_SAME:
    307           m_outputRows = numext::ceil(m_input_rows_eff / static_cast<float>(m_row_strides));
    308           m_outputCols = numext::ceil(m_input_cols_eff / static_cast<float>(m_col_strides));
    309           // Calculate the padding
    310           m_rowPaddingTop = ((m_outputRows - 1) * m_row_strides + m_patch_rows_eff - m_input_rows_eff) / 2;
    311           m_colPaddingLeft = ((m_outputCols - 1) * m_col_strides + m_patch_cols_eff - m_input_cols_eff) / 2;
    312           // The padding size calculation for PADDING_SAME has been updated to
    313           // be consistent with how TensorFlow extracts its paddings.
    314           m_rowPaddingTop = numext::maxi<Index>(0, m_rowPaddingTop);
    315           m_colPaddingLeft = numext::maxi<Index>(0, m_colPaddingLeft);
    316           break;
    317         default:
    318           eigen_assert(false && "unexpected padding");
    319           m_outputCols=0; // silence the uninitialised warning;
    320           m_outputRows=0; //// silence the uninitialised warning;
    321       }
    322     }
    323     eigen_assert(m_outputRows > 0);
    324     eigen_assert(m_outputCols > 0);
    325 
    326     // Dimensions for result of extraction.
    327     if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
    328       // ColMajor
    329       // 0: depth
    330       // 1: patch_rows
    331       // 2: patch_cols
    332       // 3: number of patches
    333       // 4 and beyond: anything else (such as batch).
    334       m_dimensions[0] = input_dims[0];
    335       m_dimensions[1] = op.patch_rows();
    336       m_dimensions[2] = op.patch_cols();
    337       m_dimensions[3] = m_outputRows * m_outputCols;
    338       for (int i = 4; i < NumDims; ++i) {
    339         m_dimensions[i] = input_dims[i-1];
    340       }
    341     } else {
    342       // RowMajor
    343       // NumDims-1: depth
    344       // NumDims-2: patch_rows
    345       // NumDims-3: patch_cols
    346       // NumDims-4: number of patches
    347       // NumDims-5 and beyond: anything else (such as batch).
    348       m_dimensions[NumDims-1] = input_dims[NumInputDims-1];
    349       m_dimensions[NumDims-2] = op.patch_rows();
    350       m_dimensions[NumDims-3] = op.patch_cols();
    351       m_dimensions[NumDims-4] = m_outputRows * m_outputCols;
    352       for (int i = NumDims-5; i >= 0; --i) {
    353         m_dimensions[i] = input_dims[i];
    354       }
    355     }
    356 
    357     // Strides for moving the patch in various dimensions.
    358     if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
    359       m_colStride = m_dimensions[1];
    360       m_patchStride = m_colStride * m_dimensions[2] * m_dimensions[0];
    361       m_otherStride = m_patchStride * m_dimensions[3];
    362     } else {
    363       m_colStride = m_dimensions[NumDims-2];
    364       m_patchStride = m_colStride * m_dimensions[NumDims-3] * m_dimensions[NumDims-1];
    365       m_otherStride = m_patchStride * m_dimensions[NumDims-4];
    366     }
    367 
    368     // Strides for navigating through the input tensor.
    369     m_rowInputStride = m_inputDepth;
    370     m_colInputStride = m_inputDepth * m_inputRows;
    371     m_patchInputStride = m_inputDepth * m_inputRows * m_inputCols;
    372 
    373     // Fast representations of different variables.
    374     m_fastOtherStride = internal::TensorIntDivisor<Index>(m_otherStride);
    375     m_fastPatchStride = internal::TensorIntDivisor<Index>(m_patchStride);
    376     m_fastColStride = internal::TensorIntDivisor<Index>(m_colStride);
    377     m_fastInflateRowStride = internal::TensorIntDivisor<Index>(m_row_inflate_strides);
    378     m_fastInflateColStride = internal::TensorIntDivisor<Index>(m_col_inflate_strides);
    379     m_fastInputColsEff = internal::TensorIntDivisor<Index>(m_input_cols_eff);
    380 
    381     // Number of patches in the width dimension.
    382     m_fastOutputRows = internal::TensorIntDivisor<Index>(m_outputRows);
    383     if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
    384       m_fastOutputDepth = internal::TensorIntDivisor<Index>(m_dimensions[0]);
    385     } else {
    386       m_fastOutputDepth = internal::TensorIntDivisor<Index>(m_dimensions[NumDims-1]);
    387     }
    388   }
    389 
    390   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Dimensions& dimensions() const { return m_dimensions; }
    391 
    392   EIGEN_STRONG_INLINE bool evalSubExprsIfNeeded(EvaluatorPointerType /*data*/) {
    393     m_impl.evalSubExprsIfNeeded(NULL);
    394     return true;
    395   }
    396 
    397 #ifdef EIGEN_USE_THREADS
    398   template <typename EvalSubExprsCallback>
    399   EIGEN_STRONG_INLINE void evalSubExprsIfNeededAsync(
    400       EvaluatorPointerType, EvalSubExprsCallback done) {
    401     m_impl.evalSubExprsIfNeededAsync(nullptr, [done](bool) { done(true); });
    402   }
    403 #endif  // EIGEN_USE_THREADS
    404 
    405   EIGEN_STRONG_INLINE void cleanup() {
    406     m_impl.cleanup();
    407   }
    408 
    409   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE CoeffReturnType coeff(Index index) const
    410   {
    411     // Patch index corresponding to the passed in index.
    412     const Index patchIndex = index / m_fastPatchStride;
    413     // Find the offset of the element wrt the location of the first element.
    414     const Index patchOffset = (index - patchIndex * m_patchStride) / m_fastOutputDepth;
    415 
    416     // Other ways to index this element.
    417     const Index otherIndex = (NumDims == 4) ? 0 : index / m_fastOtherStride;
    418     const Index patch2DIndex = (NumDims == 4) ? patchIndex : (index - otherIndex * m_otherStride) / m_fastPatchStride;
    419 
    420     // Calculate col index in the input original tensor.
    421     const Index colIndex = patch2DIndex / m_fastOutputRows;
    422     const Index colOffset = patchOffset / m_fastColStride;
    423     const Index inputCol = colIndex * m_col_strides + colOffset * m_in_col_strides - m_colPaddingLeft;
    424     const Index origInputCol = (m_col_inflate_strides == 1) ? inputCol : ((inputCol >= 0) ? (inputCol / m_fastInflateColStride) : 0);
    425     if (inputCol < 0 || inputCol >= m_input_cols_eff ||
    426         ((m_col_inflate_strides != 1) && (inputCol != origInputCol * m_col_inflate_strides))) {
    427       return Scalar(m_paddingValue);
    428     }
    429 
    430     // Calculate row index in the original input tensor.
    431     const Index rowIndex = patch2DIndex - colIndex * m_outputRows;
    432     const Index rowOffset = patchOffset - colOffset * m_colStride;
    433     const Index inputRow = rowIndex * m_row_strides + rowOffset * m_in_row_strides - m_rowPaddingTop;
    434     const Index origInputRow = (m_row_inflate_strides == 1) ? inputRow : ((inputRow >= 0) ? (inputRow / m_fastInflateRowStride) : 0);
    435     if (inputRow < 0 || inputRow >= m_input_rows_eff ||
    436         ((m_row_inflate_strides != 1) && (inputRow != origInputRow * m_row_inflate_strides))) {
    437       return Scalar(m_paddingValue);
    438     }
    439 
    440     const int depth_index = static_cast<int>(Layout) == static_cast<int>(ColMajor) ? 0 : NumDims - 1;
    441     const Index depth = index - (index / m_fastOutputDepth) * m_dimensions[depth_index];
    442 
    443     const Index inputIndex = depth + origInputRow * m_rowInputStride + origInputCol * m_colInputStride + otherIndex * m_patchInputStride;
    444     return m_impl.coeff(inputIndex);
    445   }
    446 
    447   template<int LoadMode>
    448   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE PacketReturnType packet(Index index) const
    449   {
    450     EIGEN_STATIC_ASSERT((PacketSize > 1), YOU_MADE_A_PROGRAMMING_MISTAKE)
    451     eigen_assert(index+PacketSize-1 < dimensions().TotalSize());
    452 
    453     if (m_in_row_strides != 1 || m_in_col_strides != 1 || m_row_inflate_strides != 1 || m_col_inflate_strides != 1) {
    454       return packetWithPossibleZero(index);
    455     }
    456 
    457     const Index indices[2] = {index, index + PacketSize - 1};
    458     const Index patchIndex = indices[0] / m_fastPatchStride;
    459     if (patchIndex != indices[1] / m_fastPatchStride) {
    460       return packetWithPossibleZero(index);
    461     }
    462     const Index otherIndex = (NumDims == 4) ? 0 : indices[0] / m_fastOtherStride;
    463     eigen_assert(otherIndex == indices[1] / m_fastOtherStride);
    464 
    465     // Find the offset of the element wrt the location of the first element.
    466     const Index patchOffsets[2] = {(indices[0] - patchIndex * m_patchStride) / m_fastOutputDepth,
    467                                    (indices[1] - patchIndex * m_patchStride) / m_fastOutputDepth};
    468 
    469     const Index patch2DIndex = (NumDims == 4) ? patchIndex : (indices[0] - otherIndex * m_otherStride) / m_fastPatchStride;
    470     eigen_assert(patch2DIndex == (indices[1] - otherIndex * m_otherStride) / m_fastPatchStride);
    471 
    472     const Index colIndex = patch2DIndex / m_fastOutputRows;
    473     const Index colOffsets[2] = {patchOffsets[0] / m_fastColStride, patchOffsets[1] / m_fastColStride};
    474 
    475     // Calculate col indices in the original input tensor.
    476     const Index inputCols[2] = {colIndex * m_col_strides + colOffsets[0] -
    477       m_colPaddingLeft, colIndex * m_col_strides + colOffsets[1] - m_colPaddingLeft};
    478     if (inputCols[1] < 0 || inputCols[0] >= m_inputCols) {
    479       return internal::pset1<PacketReturnType>(Scalar(m_paddingValue));
    480     }
    481 
    482     if (inputCols[0] == inputCols[1]) {
    483       const Index rowIndex = patch2DIndex - colIndex * m_outputRows;
    484       const Index rowOffsets[2] = {patchOffsets[0] - colOffsets[0]*m_colStride, patchOffsets[1] - colOffsets[1]*m_colStride};
    485       eigen_assert(rowOffsets[0] <= rowOffsets[1]);
    486       // Calculate col indices in the original input tensor.
    487       const Index inputRows[2] = {rowIndex * m_row_strides + rowOffsets[0] -
    488         m_rowPaddingTop, rowIndex * m_row_strides + rowOffsets[1] - m_rowPaddingTop};
    489 
    490       if (inputRows[1] < 0 || inputRows[0] >= m_inputRows) {
    491         return internal::pset1<PacketReturnType>(Scalar(m_paddingValue));
    492       }
    493 
    494       if (inputRows[0] >= 0 && inputRows[1] < m_inputRows) {
    495         // no padding
    496         const int depth_index = static_cast<int>(Layout) == static_cast<int>(ColMajor) ? 0 : NumDims - 1;
    497         const Index depth = index - (index / m_fastOutputDepth) * m_dimensions[depth_index];
    498         const Index inputIndex = depth + inputRows[0] * m_rowInputStride + inputCols[0] * m_colInputStride + otherIndex * m_patchInputStride;
    499         return m_impl.template packet<Unaligned>(inputIndex);
    500       }
    501     }
    502 
    503     return packetWithPossibleZero(index);
    504   }
    505 
    506   EIGEN_DEVICE_FUNC EvaluatorPointerType data() const { return NULL; }
    507 
    508   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const TensorEvaluator<ArgType, Device>& impl() const { return m_impl; }
    509 
    510 #ifdef EIGEN_USE_SYCL
    511   // binding placeholder accessors to a command group handler for SYCL
    512   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void bind(cl::sycl::handler &cgh) const {
    513     m_impl.bind(cgh);
    514   }
    515 #endif
    516 
    517   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index rowPaddingTop() const { return m_rowPaddingTop; }
    518   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index colPaddingLeft() const { return m_colPaddingLeft; }
    519   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index outputRows() const { return m_outputRows; }
    520   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index outputCols() const { return m_outputCols; }
    521   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index userRowStride() const { return m_row_strides; }
    522   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index userColStride() const { return m_col_strides; }
    523   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index userInRowStride() const { return m_in_row_strides; }
    524   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index userInColStride() const { return m_in_col_strides; }
    525   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index rowInflateStride() const { return m_row_inflate_strides; }
    526   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Index colInflateStride() const { return m_col_inflate_strides; }
    527 
    528   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE TensorOpCost
    529   costPerCoeff(bool vectorized) const {
    530     // We conservatively estimate the cost for the code path where the computed
    531     // index is inside the original image and
    532     // TensorEvaluator<ArgType, Device>::CoordAccess is false.
    533     const double compute_cost = 3 * TensorOpCost::DivCost<Index>() +
    534                                 6 * TensorOpCost::MulCost<Index>() +
    535                                 8 * TensorOpCost::MulCost<Index>();
    536     return m_impl.costPerCoeff(vectorized) +
    537            TensorOpCost(0, 0, compute_cost, vectorized, PacketSize);
    538   }
    539 
    540  protected:
    541   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE PacketReturnType packetWithPossibleZero(Index index) const
    542   {
    543     EIGEN_ALIGN_MAX typename internal::remove_const<CoeffReturnType>::type values[PacketSize];
    544     EIGEN_UNROLL_LOOP
    545     for (int i = 0; i < PacketSize; ++i) {
    546       values[i] = coeff(index+i);
    547     }
    548     PacketReturnType rslt = internal::pload<PacketReturnType>(values);
    549     return rslt;
    550   }
    551 
    552   Dimensions m_dimensions;
    553 
    554   Index m_otherStride;
    555   Index m_patchStride;
    556   Index m_colStride;
    557   Index m_row_strides;
    558   Index m_col_strides;
    559 
    560   Index m_in_row_strides;
    561   Index m_in_col_strides;
    562   Index m_row_inflate_strides;
    563   Index m_col_inflate_strides;
    564 
    565   Index m_input_rows_eff;
    566   Index m_input_cols_eff;
    567   Index m_patch_rows_eff;
    568   Index m_patch_cols_eff;
    569 
    570   internal::TensorIntDivisor<Index> m_fastOtherStride;
    571   internal::TensorIntDivisor<Index> m_fastPatchStride;
    572   internal::TensorIntDivisor<Index> m_fastColStride;
    573   internal::TensorIntDivisor<Index> m_fastInflateRowStride;
    574   internal::TensorIntDivisor<Index> m_fastInflateColStride;
    575   internal::TensorIntDivisor<Index> m_fastInputColsEff;
    576 
    577   Index m_rowInputStride;
    578   Index m_colInputStride;
    579   Index m_patchInputStride;
    580 
    581   Index m_inputDepth;
    582   Index m_inputRows;
    583   Index m_inputCols;
    584 
    585   Index m_outputRows;
    586   Index m_outputCols;
    587 
    588   Index m_rowPaddingTop;
    589   Index m_colPaddingLeft;
    590 
    591   internal::TensorIntDivisor<Index> m_fastOutputRows;
    592   internal::TensorIntDivisor<Index> m_fastOutputDepth;
    593 
    594   Scalar m_paddingValue;
    595 
    596   const Device EIGEN_DEVICE_REF m_device;
    597   TensorEvaluator<ArgType, Device> m_impl;
    598 };
    599 
    600 
    601 } // end namespace Eigen
    602 
    603 #endif // EIGEN_CXX11_TENSOR_TENSOR_IMAGE_PATCH_H