Improved and cleaned up the 2d patch extraction code

1 files changed, 181 insertions, 65 deletions

diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorImagePatch.h b/unsupported/Eigen/CXX11/src/Tensor/TensorImagePatch.h
index 478696c65..f2c56a9ac 100644
--- a/unsupported/Eigen/CXX11/src/Tensor/TensorImagePatch.h
+++ b/unsupported/Eigen/CXX11/src/Tensor/TensorImagePatch.h
@@ -30,7 +30,7 @@ namespace internal {
 template<DenseIndex Rows, DenseIndex Cols, typename XprType>
 struct traits<TensorImagePatchOp<Rows, Cols, XprType> > : public traits<XprType>
 {
-  typedef typename XprType::Scalar Scalar;
+  typedef typename internal::remove_const<typename XprType::Scalar>::type Scalar;
   typedef traits<XprType> XprTraits;
   typedef typename packet_traits<Scalar>::type Packet;
   typedef typename XprTraits::StorageKind StorageKind;
@@ -70,10 +70,30 @@ class TensorImagePatchOp : public TensorBase<TensorImagePatchOp<Rows, Cols, XprT
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE TensorImagePatchOp(const XprType& expr, DenseIndex patch_rows, DenseIndex patch_cols,
                                                            DenseIndex row_strides, DenseIndex col_strides,
-                                                           PaddingType padding_type)
+                                                           DenseIndex in_row_strides, DenseIndex in_col_strides,
+                                                           DenseIndex row_inflate_strides, DenseIndex col_inflate_strides,
+                                                           PaddingType padding_type, Scalar padding_value)
       : m_xpr(expr), m_patch_rows(patch_rows), m_patch_cols(patch_cols),
         m_row_strides(row_strides), m_col_strides(col_strides),
-        m_padding_type(padding_type) {}
+        m_in_row_strides(in_row_strides), m_in_col_strides(in_col_strides),
+        m_row_inflate_strides(row_inflate_strides), m_col_inflate_strides(col_inflate_strides),
+        m_padding_explicit(false), m_padding_top(0), m_padding_bottom(0), m_padding_left(0), m_padding_right(0),
+        m_padding_type(padding_type), m_padding_value(padding_value) {}
+
+  EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE TensorImagePatchOp(const XprType& expr, DenseIndex patch_rows, DenseIndex patch_cols,
+                                                           DenseIndex row_strides, DenseIndex col_strides,
+                                                           DenseIndex in_row_strides, DenseIndex in_col_strides,
+                                                           DenseIndex row_inflate_strides, DenseIndex col_inflate_strides,
+                                                           DenseIndex padding_top, DenseIndex padding_bottom,
+                                                           DenseIndex padding_left, DenseIndex padding_right,
+                                                           Scalar padding_value)
+      : m_xpr(expr), m_patch_rows(patch_rows), m_patch_cols(patch_cols),
+        m_row_strides(row_strides), m_col_strides(col_strides),
+        m_in_row_strides(in_row_strides), m_in_col_strides(in_col_strides),
+        m_row_inflate_strides(row_inflate_strides), m_col_inflate_strides(col_inflate_strides),
+        m_padding_explicit(true), m_padding_top(padding_top), m_padding_bottom(padding_bottom),
+        m_padding_left(padding_left), m_padding_right(padding_right),
+        m_padding_type(PADDING_VALID), m_padding_value(padding_value) {}
 
     EIGEN_DEVICE_FUNC
     DenseIndex patch_rows() const { return m_patch_rows; }
@@ -84,7 +104,27 @@ class TensorImagePatchOp : public TensorBase<TensorImagePatchOp<Rows, Cols, XprT
     EIGEN_DEVICE_FUNC
     DenseIndex col_strides() const { return m_col_strides; }
     EIGEN_DEVICE_FUNC
+    DenseIndex in_row_strides() const { return m_in_row_strides; }
+    EIGEN_DEVICE_FUNC
+    DenseIndex in_col_strides() const { return m_in_col_strides; }
+    EIGEN_DEVICE_FUNC
+    DenseIndex row_inflate_strides() const { return m_row_inflate_strides; }
+    EIGEN_DEVICE_FUNC
+    DenseIndex col_inflate_strides() const { return m_col_inflate_strides; }
+    EIGEN_DEVICE_FUNC
+    bool padding_explicit() const { return m_padding_explicit; }
+    EIGEN_DEVICE_FUNC
+    DenseIndex padding_top() const { return m_padding_top; }
+    EIGEN_DEVICE_FUNC
+    DenseIndex padding_bottom() const { return m_padding_bottom; }
+    EIGEN_DEVICE_FUNC
+    DenseIndex padding_left() const { return m_padding_left; }
+    EIGEN_DEVICE_FUNC
+    DenseIndex padding_right() const { return m_padding_right; }
+    EIGEN_DEVICE_FUNC
     PaddingType padding_type() const { return m_padding_type; }
+    EIGEN_DEVICE_FUNC
+    Scalar padding_value() const { return m_padding_value; }
 
     EIGEN_DEVICE_FUNC
     const typename internal::remove_all<typename XprType::Nested>::type&
@@ -96,10 +136,19 @@ class TensorImagePatchOp : public TensorBase<TensorImagePatchOp<Rows, Cols, XprT
     const DenseIndex m_patch_cols;
     const DenseIndex m_row_strides;
     const DenseIndex m_col_strides;
+    const DenseIndex m_in_row_strides;
+    const DenseIndex m_in_col_strides;
+    const DenseIndex m_row_inflate_strides;
+    const DenseIndex m_col_inflate_strides;
+    const bool m_padding_explicit;
+    const DenseIndex m_padding_top;
+    const DenseIndex m_padding_bottom;
+    const DenseIndex m_padding_left;
+    const DenseIndex m_padding_right;
     const PaddingType m_padding_type;
+    const Scalar m_padding_value;
 };
 
-
 // Eval as rvalue
 template<DenseIndex Rows, DenseIndex Cols, typename ArgType, typename Device>
 struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
@@ -109,7 +158,10 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
   static const int NumInputDims = internal::array_size<typename TensorEvaluator<ArgType, Device>::Dimensions>::value;
   static const int NumDims = NumInputDims + 1;
   typedef DSizes<Index, NumDims> Dimensions;
-  typedef typename XprType::Scalar Scalar;
+  typedef typename internal::remove_const<typename XprType::Scalar>::type Scalar;
+  typedef TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>,
+                          Device> Self;
+  typedef TensorEvaluator<ArgType, Device> Impl;
 
   enum {
     IsAligned = false,
@@ -123,13 +175,17 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
   {
     EIGEN_STATIC_ASSERT(NumDims >= 4, YOU_MADE_A_PROGRAMMING_MISTAKE);
 
+    m_paddingValue = op.padding_value();
+
     const typename TensorEvaluator<ArgType, Device>::Dimensions& input_dims = m_impl.dimensions();
 
     // Caches a few variables.
     if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
+      m_inputDepth = input_dims[0];
       m_inputRows = input_dims[1];
       m_inputCols = input_dims[2];
     } else {
+      m_inputDepth = input_dims[NumInputDims-1];
       m_inputRows = input_dims[NumInputDims-2];
       m_inputCols = input_dims[NumInputDims-3];
     }
@@ -137,27 +193,57 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
     m_row_strides = op.row_strides();
     m_col_strides = op.col_strides();
 
-    // We only support same strides for both dimensions and square patches.
-    eigen_assert(m_row_strides == m_col_strides);
-
-    switch (op.padding_type()) {
-      case PADDING_VALID:
-        m_outputRows = numext::ceil((m_inputRows - op.patch_rows() + 1.f) / static_cast<float>(m_row_strides));
-        m_outputCols = numext::ceil((m_inputCols - op.patch_cols() + 1.f) / static_cast<float>(m_col_strides));
-        // Calculate the padding
-        m_rowPaddingTop = ((m_outputRows - 1) * m_row_strides + op.patch_rows() - m_inputRows) / 2;
-        m_colPaddingLeft = ((m_outputCols - 1) * m_col_strides + op.patch_cols() - m_inputCols) / 2;
-        break;
-      case PADDING_SAME:
-        m_outputRows = numext::ceil(m_inputRows / static_cast<float>(m_row_strides));
-        m_outputCols = numext::ceil(m_inputCols / static_cast<float>(m_col_strides));
-        // Calculate the padding
-        m_rowPaddingTop = ((m_outputRows - 1) * m_row_strides + op.patch_rows() - m_inputRows) / 2;
-        m_colPaddingLeft = ((m_outputCols - 1) * m_col_strides + op.patch_cols() - m_inputCols) / 2;
-        break;
-      default:
-        eigen_assert(false && "unexpected padding");
+    // Input strides and effective input/patch size
+    m_in_row_strides = op.in_row_strides();
+    m_in_col_strides = op.in_col_strides();
+    m_row_inflate_strides = op.row_inflate_strides();
+    m_col_inflate_strides = op.col_inflate_strides();
+    // The "effective" input rows and input cols are the input rows and cols
+    // after inflating them with zeros.
+    // For examples, a 2x3 matrix with row_inflate_strides and
+    // col_inflate_strides of 2 comes from:
+    //   A B C
+    //   D E F
+    //
+    // to a matrix is 3 x 5:
+    //
+    //   A . B . C
+    //   . . . . .
+    //   D . E . F
+
+    m_input_rows_eff = (m_inputRows - 1) * m_row_inflate_strides + 1;
+    m_input_cols_eff = (m_inputCols - 1) * m_col_inflate_strides + 1;
+    m_patch_rows_eff = op.patch_rows() + (op.patch_rows() - 1) * (m_in_row_strides - 1);
+    m_patch_cols_eff = op.patch_cols() + (op.patch_cols() - 1) * (m_in_col_strides - 1);
+
+    if (op.padding_explicit()) {
+      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));
+      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));
+      m_rowPaddingTop = op.padding_top();
+      m_colPaddingLeft = op.padding_left();
+    } else {
+      // Computing padding from the type
+      switch (op.padding_type()) {
+        case PADDING_VALID:
+          m_outputRows = numext::ceil((m_input_rows_eff - m_patch_rows_eff + 1.f) / static_cast<float>(m_row_strides));
+          m_outputCols = numext::ceil((m_input_cols_eff - m_patch_cols_eff + 1.f) / static_cast<float>(m_col_strides));
+          // Calculate the padding
+          m_rowPaddingTop = ((m_outputRows - 1) * m_row_strides + m_patch_rows_eff - m_input_rows_eff) / 2;
+          m_colPaddingLeft = ((m_outputCols - 1) * m_col_strides + m_patch_cols_eff - m_input_cols_eff) / 2;
+          break;
+        case PADDING_SAME:
+          m_outputRows = numext::ceil(m_input_rows_eff / static_cast<float>(m_row_strides));
+          m_outputCols = numext::ceil(m_input_cols_eff / static_cast<float>(m_col_strides));
+          // Calculate the padding
+          m_rowPaddingTop = ((m_outputRows - 1) * m_row_strides + m_patch_rows_eff - m_input_rows_eff) / 2;
+          m_colPaddingLeft = ((m_outputCols - 1) * m_col_strides + m_patch_cols_eff - m_input_cols_eff) / 2;
+          break;
+        default:
+          eigen_assert(false && "unexpected padding");
       }
+    }
+    eigen_assert(m_outputRows > 0);
+    eigen_assert(m_outputCols > 0);
 
     // Dimensions for result of extraction.
     if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
@@ -202,26 +288,24 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
     }
 
     // Strides for navigating through the input tensor.
-    if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
-      m_rowInputStride = input_dims[0];
-      m_colInputStride = input_dims[0] * input_dims[1];
-      m_patchInputStride = input_dims[0] * input_dims[1] * input_dims[2];
-    } else {
-      m_rowInputStride = input_dims[NumInputDims-1];
-      m_colInputStride = input_dims[NumInputDims-1] * input_dims[NumInputDims-2];
-      m_patchInputStride = input_dims[NumInputDims-1] * input_dims[NumInputDims-2] * input_dims[NumInputDims-3];
-    }
+    m_rowInputStride = m_inputDepth;
+    m_colInputStride = m_inputDepth * m_inputRows;
+    m_patchInputStride = m_inputDepth * m_inputRows * m_inputCols;
 
     // Fast representations of different variables.
     m_fastOtherStride = internal::TensorIntDivisor<Index>(m_otherStride);
     m_fastPatchStride = internal::TensorIntDivisor<Index>(m_patchStride);
     m_fastColStride = internal::TensorIntDivisor<Index>(m_colStride);
+    m_fastInputRowStride = internal::TensorIntDivisor<Index>(m_row_inflate_strides);
+    m_fastInputColStride = internal::TensorIntDivisor<Index>(m_col_inflate_strides);
+    m_fastInputColsEff = internal::TensorIntDivisor<Index>(m_input_cols_eff);
+
     // Number of patches in the width dimension.
     m_fastOutputRows = internal::TensorIntDivisor<Index>(m_outputRows);
     if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
-      m_fastDimZero = internal::TensorIntDivisor<Index>(m_dimensions[0]);
+      m_fastOutputDepth = internal::TensorIntDivisor<Index>(m_dimensions[0]);
     } else {
-      m_fastDimZero = internal::TensorIntDivisor<Index>(m_dimensions[NumDims-1]);
+      m_fastOutputDepth = internal::TensorIntDivisor<Index>(m_dimensions[NumDims-1]);
     }
   }
 
@@ -244,33 +328,36 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
     // Patch index corresponding to the passed in index.
     const Index patchIndex = index / m_fastPatchStride;
     // Find the offset of the element wrt the location of the first element.
-    const Index patchOffset = (index - patchIndex * m_patchStride) / m_fastDimZero;
+    const Index patchOffset = (index - patchIndex * m_patchStride) / m_fastOutputDepth;
 
     // Other ways to index this element.
     const Index otherIndex = (NumDims == 4) ? 0 : index / m_fastOtherStride;
     const Index patch2DIndex = (NumDims == 4) ? patchIndex : (index - otherIndex * m_otherStride) / m_fastPatchStride;
 
+    // Calculate col index in the input original tensor.
     const Index colIndex = patch2DIndex / m_fastOutputRows;
     const Index colOffset = patchOffset / m_fastColStride;
-
-    // Calculate col index in the input original tensor.
-    const Index inputCol = colIndex * m_col_strides + colOffset - m_colPaddingLeft;
-    if (inputCol < 0 || inputCol >= m_inputCols) {
-      return Scalar(0);
+    const Index inputCol = colIndex * m_col_strides + colOffset * m_in_col_strides - m_colPaddingLeft;
+    const Index origInputCol = (m_col_inflate_strides == 1) ? inputCol : ((inputCol >= 0) ? (inputCol / m_fastInputColStride) : 0);
+    if (inputCol < 0 || inputCol >= m_input_cols_eff ||
+        ((m_col_inflate_strides != 1) && (inputCol != origInputCol * m_col_inflate_strides))) {
+      return Scalar(m_paddingValue);
     }
-    const Index rowIndex = patch2DIndex - colIndex * m_outputRows;
-    const Index rowOffset = patchOffset - colOffset * m_colStride;
 
     // Calculate row index in the original input tensor.
-    const Index inputRow = rowIndex * m_row_strides + rowOffset - m_rowPaddingTop;
-    if (inputRow < 0 || inputRow >= m_inputRows) {
-      return Scalar(0);
+    const Index rowIndex = patch2DIndex - colIndex * m_outputRows;
+    const Index rowOffset = patchOffset - colOffset * m_colStride;
+    const Index inputRow = rowIndex * m_row_strides + rowOffset * m_in_row_strides - m_rowPaddingTop;
+    const Index origInputRow = (m_row_inflate_strides == 1) ? inputRow : ((inputRow >= 0) ? (inputRow / m_fastInputRowStride) : 0);
+    if (inputRow < 0 || inputRow >= m_input_rows_eff ||
+        ((m_row_inflate_strides != 1) && (inputRow != origInputRow * m_row_inflate_strides))) {
+      return Scalar(m_paddingValue);
     }
 
     const int depth_index = static_cast<int>(Layout) == static_cast<int>(ColMajor) ? 0 : NumDims - 1;
-    const Index depth = index - (index / m_fastDimZero) * m_dimensions[depth_index];
+    const Index depth = index - (index / m_fastOutputDepth) * m_dimensions[depth_index];
 
-    const Index inputIndex = depth + inputRow * m_rowInputStride + inputCol * m_colInputStride + otherIndex * m_patchInputStride;
+    const Index inputIndex = depth + origInputRow * m_rowInputStride + origInputCol * m_colInputStride + otherIndex * m_patchInputStride;
     return m_impl.coeff(inputIndex);
   }
 
@@ -281,6 +368,10 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
     EIGEN_STATIC_ASSERT(packetSize > 1, YOU_MADE_A_PROGRAMMING_MISTAKE)
     eigen_assert(index+packetSize-1 < dimensions().TotalSize());
 
+    if (m_in_row_strides != 1 || m_in_col_strides != 1 || m_row_inflate_strides != 1 || m_col_inflate_strides != 1) {
+      return packetWithPossibleZero(index);
+    }
+
     const Index indices[2] = {index, index + packetSize - 1};
     const Index patchIndex = indices[0] / m_fastPatchStride;
     if (patchIndex != indices[1] / m_fastPatchStride) {
@@ -290,8 +381,8 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
     eigen_assert(otherIndex == indices[1] / m_fastOtherStride);
 
     // Find the offset of the element wrt the location of the first element.
-    const Index patchOffsets[2] = {(indices[0] - patchIndex * m_patchStride) / m_fastDimZero,
-                                   (indices[1] - patchIndex * m_patchStride) / m_fastDimZero};
+    const Index patchOffsets[2] = {(indices[0] - patchIndex * m_patchStride) / m_fastOutputDepth,
+                                   (indices[1] - patchIndex * m_patchStride) / m_fastOutputDepth};
 
     const Index patch2DIndex = (NumDims == 4) ? patchIndex : (indices[0] - otherIndex * m_otherStride) / m_fastPatchStride;
     eigen_assert(patch2DIndex == (indices[1] - otherIndex * m_otherStride) / m_fastPatchStride);
@@ -303,8 +394,7 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
     const Index inputCols[2] = {colIndex * m_col_strides + colOffsets[0] -
       m_colPaddingLeft, colIndex * m_col_strides + colOffsets[1] - m_colPaddingLeft};
     if (inputCols[1] < 0 || inputCols[0] >= m_inputCols) {
-      // all zeros
-      return internal::pset1<PacketReturnType>(Scalar(0));
+      return internal::pset1<PacketReturnType>(Scalar(m_paddingValue));
     }
 
     if (inputCols[0] == inputCols[1]) {
@@ -316,14 +406,13 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
         m_rowPaddingTop, rowIndex * m_row_strides + rowOffsets[1] - m_rowPaddingTop};
 
       if (inputRows[1] < 0 || inputRows[0] >= m_inputRows) {
-        // all zeros
-        return internal::pset1<PacketReturnType>(Scalar(0));
+        return internal::pset1<PacketReturnType>(Scalar(m_paddingValue));
       }
 
       if (inputRows[0] >= 0 && inputRows[1] < m_inputRows) {
         // no padding
         const int depth_index = static_cast<int>(Layout) == static_cast<int>(ColMajor) ? 0 : NumDims - 1;
-        const Index depth = index - (index / m_fastDimZero) * m_dimensions[depth_index];
+        const Index depth = index - (index / m_fastOutputDepth) * m_dimensions[depth_index];
         const Index inputIndex = depth + inputRows[0] * m_rowInputStride + inputCols[0] * m_colInputStride + otherIndex * m_patchInputStride;
         return m_impl.template packet<Unaligned>(inputIndex);
       }
@@ -342,6 +431,10 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
   Index outputCols() const { return m_outputCols; }
   Index userRowStride() const { return m_row_strides; }
   Index userColStride() const { return m_col_strides; }
+  Index userInRowStride() const { return m_in_row_strides; }
+  Index userInColStride() const { return m_in_col_strides; }
+  Index rowInflateStride() const { return m_row_inflate_strides; }
+  Index colInflateStride() const { return m_col_inflate_strides; }
 
   EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE CoeffReturnType coeff(const array<Index, NumDims>& coords) const
   {
@@ -350,24 +443,30 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
     // 0: d, 1: patch_rows, 2: patch_cols, 3: number of patches, 4: number of batches
     // RowMajor
     // 0: number of batches, 1: number of patches, 2: patch_cols , 3: patch_rows, 4: d
-    const Index patchIndex = coords[static_cast<int>(Layout) == static_cast<int>(ColMajor) ? 3 : 1];
+    const Index patch2DIndex = coords[static_cast<int>(Layout) == static_cast<int>(ColMajor) ? 3 : 1];
 
     array<Index, NumDims-1> inputCoords;
+    Index input_col_idx = patch2DIndex / m_fastInputColsEff;
+    Index inputCol = input_col_idx  + coords[1] * m_in_row_strides - m_rowPaddingTop;
+    Index inputRow = patch2DIndex - input_col_idx * m_input_cols_eff + coords[2] * m_in_col_strides - m_colPaddingLeft;
+    const Index origInputCol = (m_col_inflate_strides == 1) ? inputCol : ((inputCol >= 0) ? (inputCol / m_fastInputColStride) : 0);
+    const Index origInputRow = (m_row_inflate_strides == 1) ? inputRow : ((inputRow >= 0) ? (inputRow / m_fastInputRowStride) : 0);
     if (static_cast<int>(Layout) == static_cast<int>(ColMajor)) {
       inputCoords[0] = coords[0];  // depth
-      inputCoords[1] = patchIndex / m_inputCols  + coords[1] - m_rowPaddingTop;
-      inputCoords[2] = patchIndex - patchIndex / m_inputCols * m_inputCols + coords[2] - m_colPaddingLeft;
+      inputCoords[1] = origInputCol;
+      inputCoords[2] = origInputRow;
       inputCoords[3] = coords[4];  // batch
     } else {
       inputCoords[3] = coords[4];  // depth
-      inputCoords[2] = patchIndex / m_inputCols  + coords[3] - m_rowPaddingTop;
-      inputCoords[1] = patchIndex - patchIndex / m_inputCols * m_inputCols + coords[2] - m_colPaddingLeft;
+      inputCoords[2] = origInputCol;
+      inputCoords[1] = origInputRow;
       inputCoords[0] = coords[0];  // batch
     }
     // If the computed coordinates are outside the original image perimeter, return 0.
-    if (inputCoords[1] < 0 || inputCoords[1] >= m_inputRows ||
-        inputCoords[2] < 0 || inputCoords[2] >= m_inputCols) {
-      return Scalar(0);
+    if (inputCol < 0 || inputCol >= m_input_cols_eff || inputRow < 0 || inputRow >= m_input_rows_eff ||
+        ((m_col_inflate_strides != 1) && (inputCol != origInputCol * m_col_inflate_strides)) ||
+        ((m_row_inflate_strides != 1) && (inputRow != origInputRow * m_row_inflate_strides))) {
+      return Scalar(m_paddingValue);
     }
     if (TensorEvaluator<ArgType, Device>::CoordAccess) {
       return m_impl.coeff(inputCoords);
@@ -409,14 +508,29 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
   Index m_colStride;
   Index m_row_strides;
   Index m_col_strides;
+
+  Index m_in_row_strides;
+  Index m_in_col_strides;
+  Index m_row_inflate_strides;
+  Index m_col_inflate_strides;
+
+  Index m_input_rows_eff;
+  Index m_input_cols_eff;
+  Index m_patch_rows_eff;
+  Index m_patch_cols_eff;
+
   internal::TensorIntDivisor<Index> m_fastOtherStride;
   internal::TensorIntDivisor<Index> m_fastPatchStride;
   internal::TensorIntDivisor<Index> m_fastColStride;
+  internal::TensorIntDivisor<Index> m_fastInputRowStride;
+  internal::TensorIntDivisor<Index> m_fastInputColStride;
+  internal::TensorIntDivisor<Index> m_fastInputColsEff;
 
   Index m_rowInputStride;
   Index m_colInputStride;
   Index m_patchInputStride;
 
+  Index m_inputDepth;
   Index m_inputRows;
   Index m_inputCols;
 
@@ -427,7 +541,9 @@ struct TensorEvaluator<const TensorImagePatchOp<Rows, Cols, ArgType>, Device>
   Index m_colPaddingLeft;
 
   internal::TensorIntDivisor<Index> m_fastOutputRows;
-  internal::TensorIntDivisor<Index> m_fastDimZero;
+  internal::TensorIntDivisor<Index> m_fastOutputDepth;
+
+  Scalar m_paddingValue;
 
   TensorEvaluator<ArgType, Device> m_impl;
 };