Merge pull request #15491 from tink2123/new_align_corners

add align_corners and align_mode for image_resize

paddle/fluid/API.spec

@@ -142,10 +142,10 @@ paddle.fluid.layers.label_smooth ArgSpec(args=['label', 'prior_dist', 'epsilon',
 paddle.fluid.layers.roi_pool ArgSpec(args=['input', 'rois', 'pooled_height', 'pooled_width', 'spatial_scale'], varargs=None, keywords=None, defaults=(1, 1, 1.0))
 paddle.fluid.layers.roi_align ArgSpec(args=['input', 'rois', 'pooled_height', 'pooled_width', 'spatial_scale', 'sampling_ratio', 'name'], varargs=None, keywords=None, defaults=(1, 1, 1.0, -1, None))
 paddle.fluid.layers.dice_loss ArgSpec(args=['input', 'label', 'epsilon'], varargs=None, keywords=None, defaults=(1e-05,))
-paddle.fluid.layers.image_resize ArgSpec(args=['input', 'out_shape', 'scale', 'name', 'resample', 'actual_shape'], varargs=None, keywords=None, defaults=(None, None, None, 'BILINEAR', None))
+paddle.fluid.layers.image_resize ArgSpec(args=['input', 'out_shape', 'scale', 'name', 'resample', 'actual_shape', 'align_corners', 'align_mode'], varargs=None, keywords=None, defaults=(None, None, None, 'BILINEAR', None, True, 1))
 paddle.fluid.layers.image_resize_short ArgSpec(args=['input', 'out_short_len', 'resample'], varargs=None, keywords=None, defaults=('BILINEAR',))
-paddle.fluid.layers.resize_bilinear ArgSpec(args=['input', 'out_shape', 'scale', 'name', 'actual_shape'], varargs=None, keywords=None, defaults=(None, None, None, None))
-paddle.fluid.layers.resize_nearest ArgSpec(args=['input', 'out_shape', 'scale', 'name', 'actual_shape'], varargs=None, keywords=None, defaults=(None, None, None, None))
+paddle.fluid.layers.resize_bilinear ArgSpec(args=['input', 'out_shape', 'scale', 'name', 'actual_shape', 'align_corners', 'align_mode'], varargs=None, keywords=None, defaults=(None, None, None, None, True, 1))
+paddle.fluid.layers.resize_nearest ArgSpec(args=['input', 'out_shape', 'scale', 'name', 'actual_shape', 'align_corners'], varargs=None, keywords=None, defaults=(None, None, None, None, True))
 paddle.fluid.layers.gather ArgSpec(args=['input', 'index'], varargs=None, keywords=None, defaults=None)
 paddle.fluid.layers.scatter ArgSpec(args=['input', 'index', 'updates', 'name'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.layers.sequence_scatter ArgSpec(args=['input', 'index', 'updates', 'name'], varargs=None, keywords=None, defaults=(None,))

paddle/fluid/operators/interpolate_op.cc

@@ -82,6 +82,18 @@ class InterpolateOpMaker : public framework::OpProtoAndCheckerMaker {
                          "bilinear interpolation and \"nearest\" for nearest "
                          "neighbor interpolation.")
         .SetDefault("bilinear");
+    AddAttr<bool>(
+        "align_corners",
+        "an optinal bool. Defaults to True. "
+        "If True, the centers of 4 corner pixels of the input and output "
+        "tensors are aligned, preserving the values at the corner pixels, "
+        "if Flase, are not aligned")
+        .SetDefault(true);
+    AddAttr<int>("align_mode",
+                 "(int, default \'1\'), optional for bilinear interpolation"
+                 "can be \'0\' for src_idx = scale*(dst_indx+0.5)-0.5 , "
+                 "can be \'1\' for src_idx = scale*dst_index .")
+        .SetDefault(1);
     AddComment(R"DOC(
           This operator samples input X to given output shape by using specified
           interpolation method, the interpolation methods can be \"nearest\"
@@ -98,6 +110,64 @@ class InterpolateOpMaker : public framework::OpProtoAndCheckerMaker {
           to perform linear interpolation first in one direction, and then 
           again in the other direction.
 
+          Align_corners and align_mode are optinal parameters,the calculation method 
+          of interpolation can be selected by them.
+          
+          Example:
+
+          For scale:
+          
+            if align_corners = True and out_{size}>1 :
+
+              scale_{factor} = (in_{size}-1.0)/(out_{size}-1.0)
+            
+            else:
+              
+              scale_{factor} = float(in_{size}/out_{size})
+            
+          
+          Nearest neighbor interpolation:
+          
+          if:
+              align_corners = False
+
+              input : (N,C,H_in,W_in)
+              output: (N,C,H_out,W_out) where:
+
+              H_out = \left \lfloor {H_{in} * scale_{}factor}} \right \rfloor
+              W_out = \left \lfloor {W_{in} * scale_{}factor}} \right \rfloor
+
+          else:
+              align_corners = True
+
+              input : (N,C,H_in,W_in)
+              output: (N,C,H_out,W_out) where:
+
+              H_out = round(H_{in} * scale_{factor})
+              W_out = round(W_{in} * scale_{factor})
+
+          Bilinear interpolation:
+
+          if:
+              align_corners = False , align_mode = 0
+              
+              input : (N,C,H_in,W_in)
+              output: (N,C,H_out,W_out) where:
+              
+              H_out = (H_{in}+0.5) * scale_{factor} - 0.5
+              W_out = (W_{in}+0.5) * scale_{factor} - 0.5
+
+
+          else:
+           
+              input : (N,C,H_in,W_in)
+              output: (N,C,H_out,W_out) where:
+
+              H_out = H_{in} * scale_{factor}
+              W_out = W_{in} * scale_{factor}
+
+          
+
           For details of nearest neighbor interpolation, please refer to Wikipedia: 
           https://en.wikipedia.org/wiki/Nearest-neighbor_interpolation
 

paddle/fluid/operators/interpolate_op.cu

@@ -23,7 +23,8 @@ __global__ void KeNearestNeighborInterpFw(
     const T* in, const size_t in_img_h, const size_t in_img_w,
     const size_t input_h, const size_t input_w, T* out, const size_t out_img_h,
     const size_t out_img_w, const size_t output_h, const size_t output_w,
-    const size_t num_channels, const float ratio_h, const float ratio_w) {
+    const size_t num_channels, const float ratio_h, const float ratio_w,
+    const bool align_corners) {
   int nthreads = output_h * output_w;
   int tid = blockIdx.x * blockDim.x + threadIdx.x;
   int stride = blockDim.x * gridDim.x;
@@ -35,10 +36,14 @@ __global__ void KeNearestNeighborInterpFw(
     int channel_id = out_id_w / out_img_size;
 
     int out_img_idy = (out_id_w % out_img_size) / out_img_w;
-    int in_img_idy = static_cast<int>(ratio_h * out_img_idy + 0.5);
+    int in_img_idy = (align_corners)
+                         ? static_cast<int>(ratio_h * out_img_idy + 0.5)
+                         : static_cast<int>(ratio_h * out_img_idy);
 
     int out_img_idx = tid % out_img_w;
-    int in_img_idx = static_cast<int>(ratio_w * out_img_idx + 0.5);
+    int in_img_idx = (align_corners)
+                         ? static_cast<int>(ratio_w * out_img_idx + 0.5)
+                         : static_cast<int>(ratio_w * out_img_idx);
 
     out[tid] = in[out_id_h * input_w + channel_id * in_img_size +
                   in_img_idy * in_img_w + in_img_idx];
@@ -50,7 +55,8 @@ __global__ void KeNearestNeighborInterpBw(
     T* in, const size_t in_img_h, const size_t in_img_w, const size_t input_h,
     const size_t input_w, const T* out, const size_t out_img_h,
     const size_t out_img_w, const size_t output_h, const size_t output_w,
-    const size_t num_channels, const float ratio_h, const float ratio_w) {
+    const size_t num_channels, const float ratio_h, const float ratio_w,
+    const bool align_corners) {
   int nthreads = output_h * output_w;
   int tid = blockIdx.x * blockDim.x + threadIdx.x;
   int stride = blockDim.x * gridDim.x;
@@ -62,10 +68,14 @@ __global__ void KeNearestNeighborInterpBw(
     int channel_id = out_id_w / out_img_size;
 
     int out_img_idy = (out_id_w % out_img_size) / out_img_w;
-    int in_img_idy = static_cast<int>(ratio_h * out_img_idy + 0.5);
+    int in_img_idy = (align_corners)
+                         ? static_cast<int>(ratio_h * out_img_idy + 0.5)
+                         : static_cast<int>(ratio_h * out_img_idy);
 
     int out_img_idx = tid % out_img_w;
-    int in_img_idx = static_cast<int>(ratio_w * out_img_idx + 0.5);
+    int in_img_idx = (align_corners)
+                         ? static_cast<int>(ratio_w * out_img_idx + 0.5)
+                         : static_cast<int>(ratio_w * out_img_idx);
 
     T* in_pos = &in[out_id_h * input_w + channel_id * in_img_size +
                     in_img_idy * in_img_w + in_img_idx];
@@ -79,10 +89,12 @@ __global__ void KeBilinearInterpFw(
     const T* in, const size_t in_img_h, const size_t in_img_w,
     const size_t input_h, const size_t input_w, T* out, const size_t out_img_h,
     const size_t out_img_w, const size_t output_h, const size_t output_w,
-    const size_t num_channels, const float ratio_h, const float ratio_w) {
+    const size_t num_channels, const float ratio_h, const float ratio_w,
+    const bool align_corners, const int align_mode) {
   int nthreads = output_h * output_w;
   int tid = blockIdx.x * blockDim.x + threadIdx.x;
   int stride = blockDim.x * gridDim.x;
+  bool align_flag = (align_mode == 0 && !align_corners);
   for (; tid < nthreads; tid += stride) {
     int out_id_h = tid / output_w;
     int out_id_w = tid % output_w;
@@ -91,15 +103,23 @@ __global__ void KeBilinearInterpFw(
     int channel_id = out_id_w / out_img_size;
 
     int out_img_idy = (out_id_w % out_img_size) / out_img_w;
-    int in_img_idy = ratio_h * out_img_idy;
+    int in_img_idy = align_flag
+                         ? static_cast<int>(ratio_h * (out_img_idy + 0.5) - 0.5)
+                         : static_cast<int>(ratio_h * out_img_idy);
+    in_img_idy = (in_img_idy > 0) ? in_img_idy : 0;
     int h_id = (in_img_idy < in_img_h - 1) ? 1 : 0;
-    T h1lambda = ratio_h * out_img_idy - in_img_idy;
+    T h1lambda = align_flag ? ratio_h * (out_img_idy + 0.5) - 0.5 - in_img_idy
+                            : ratio_h * out_img_idy - in_img_idy;
     T h2lambda = 1.f - h1lambda;
 
     int out_img_idx = tid % out_img_w;
-    int in_img_idx = ratio_w * out_img_idx;
+    int in_img_idx = align_flag
+                         ? static_cast<int>(ratio_w * (out_img_idx + 0.5) - 0.5)
+                         : static_cast<int>(ratio_w * out_img_idx);
+    in_img_idx = (in_img_idx > 0) ? in_img_idx : 0;
     int w_id = (in_img_idx < in_img_w - 1) ? 1 : 0;
-    T w1lambda = ratio_w * out_img_idx - in_img_idx;
+    T w1lambda = align_flag ? ratio_w * (out_img_idx + 0.5) - 0.5 - in_img_idx
+                            : ratio_w * out_img_idx - in_img_idx;
     T w2lambda = 1.f - w1lambda;
 
     const T* in_pos = &in[out_id_h * input_w + channel_id * in_img_size +
@@ -118,10 +138,12 @@ __global__ void KeBilinearInterpBw(
     T* in, const size_t in_img_h, const size_t in_img_w, const size_t input_h,
     const size_t input_w, const T* out, const size_t out_img_h,
     const size_t out_img_w, const size_t output_h, const size_t output_w,
-    const size_t num_channels, const T ratio_h, const T ratio_w) {
+    const size_t num_channels, const T ratio_h, const T ratio_w,
+    const bool align_corners, const int align_mode) {
   int nthreads = output_h * output_w;
   int tid = blockIdx.x * blockDim.x + threadIdx.x;
   int stride = blockDim.x * gridDim.x;
+  bool align_flag = (align_mode == 0 && !align_corners);
   for (; tid < nthreads; tid += stride) {
     int out_id_h = tid / output_w;
     int out_id_w = tid % output_w;
@@ -130,15 +152,22 @@ __global__ void KeBilinearInterpBw(
     int channel_id = out_id_w / out_img_size;
 
     int out_img_idy = (out_id_w % out_img_size) / out_img_w;
-    int in_img_idy = ratio_h * out_img_idy;
+    int in_img_idy = align_flag ? ratio_h * (out_img_idy + 0.5) - 0.5
+                                : ratio_h * out_img_idy;
+    in_img_idy = (in_img_idy > 0) ? in_img_idy : 0;
     int h_id = (in_img_idy < in_img_h - 1) ? 1 : 0;
-    T h1lambda = ratio_h * out_img_idy - in_img_idy;
+    T h1lambda = align_flag ? ratio_h * (out_img_idy + 0.5) - 0.5 - in_img_idy
+                            : ratio_h * out_img_idy - in_img_idy;
+
     T h2lambda = 1.f - h1lambda;
 
     int out_img_idx = tid % out_img_w;
-    int in_img_idx = ratio_w * out_img_idx;
+    int in_img_idx = align_flag ? ratio_w * (out_img_idx + 0.5) - 0.5
+                                : ratio_w * out_img_idx;
+    in_img_idx = (in_img_idx > 0) ? in_img_idx : 0;
     int w_id = (in_img_idx < in_img_w - 1) ? 1 : 0;
-    T w1lambda = ratio_w * out_img_idx - in_img_idx;
+    T w1lambda = align_flag ? ratio_w * (out_img_idx + 0.5) - 0.5 - in_img_idx
+                            : ratio_w * out_img_idx - in_img_idx;
     T w2lambda = 1.f - w1lambda;
 
     T* in_pos = &in[out_id_h * input_w + channel_id * in_img_size +
@@ -175,6 +204,9 @@ class InterpolateOpCUDAKernel : public framework::OpKernel<T> {
       out_w = size_data[1];
     }
 
+    bool align_corners = ctx.Attr<bool>("align_corners");
+    int align_mode = ctx.Attr<int>("align_mode");
+
     int n = input->dims()[0];
     int c = input->dims()[1];
     int in_h = input->dims()[2];
@@ -188,10 +220,16 @@ class InterpolateOpCUDAKernel : public framework::OpKernel<T> {
     int in_chw = c * in_hw;
     int out_chw = c * out_hw;
 
-    float ratio_h =
-        (out_h > 1) ? static_cast<float>(in_h - 1) / (out_h - 1) : 0.f;
-    float ratio_w =
-        (out_w > 1) ? static_cast<float>(in_w - 1) / (out_w - 1) : 0.f;
+    float ratio_h = 0.f;
+    float ratio_w = 0.f;
+    if (out_h > 1) {
+      ratio_h = (align_corners) ? static_cast<float>(in_h - 1) / (out_h - 1)
+                                : static_cast<float>(in_h) / out_h;
+    }
+    if (out_w > 1) {
+      ratio_w = (align_corners) ? static_cast<float>(in_w - 1) / (out_w - 1)
+                                : static_cast<float>(in_w) / out_w;
+    }
 
     if (in_h == out_h && in_w == out_w) {
       framework::TensorCopy(*input, ctx.GetPlace(), output);
@@ -206,12 +244,12 @@ class InterpolateOpCUDAKernel : public framework::OpKernel<T> {
       KeNearestNeighborInterpFw<
           T><<<grid_dim, 512, 0, ctx.cuda_device_context().stream()>>>(
           input_data, in_h, in_w, n, in_chw, output_data, out_h, out_w, n,
-          out_chw, c, ratio_h, ratio_w);
+          out_chw, c, ratio_h, ratio_w, align_corners);
     } else if ("bilinear" == interp_method) {
       KeBilinearInterpFw<
           T><<<grid_dim, 512, 0, ctx.cuda_device_context().stream()>>>(
           input_data, in_h, in_w, n, in_chw, output_data, out_h, out_w, n,
-          out_chw, c, ratio_h, ratio_w);
+          out_chw, c, ratio_h, ratio_w, align_corners, align_mode);
     }
   }
 };
@@ -234,6 +272,10 @@ class InterpolateGradOpCUDAKernel : public framework::OpKernel<T> {
     int out_h = ctx.Attr<int>("out_h");
     int out_w = ctx.Attr<int>("out_w");
     auto out_size = ctx.Input<Tensor>("OutSize");
+
+    bool align_corners = ctx.Attr<bool>("align_corners");
+    int align_mode = ctx.Attr<int>("align_mode");
+
     if (out_size != nullptr) {
       Tensor sizes;
       framework::TensorCopy(*out_size, platform::CPUPlace(), &sizes);
@@ -252,10 +294,16 @@ class InterpolateGradOpCUDAKernel : public framework::OpKernel<T> {
     int in_chw = c * in_hw;
     int out_chw = c * out_hw;
 
-    float ratio_h =
-        (out_h > 1) ? static_cast<float>(in_h - 1) / (out_h - 1) : 0.f;
-    float ratio_w =
-        (out_w > 1) ? static_cast<float>(in_w - 1) / (out_w - 1) : 0.f;
+    float ratio_h = 0.f;
+    float ratio_w = 0.f;
+    if (out_h > 1) {
+      ratio_h = (align_corners) ? static_cast<float>(in_h - 1) / (out_h - 1)
+                                : static_cast<float>(in_h) / out_h;
+    }
+    if (out_w > 1) {
+      ratio_w = (align_corners) ? static_cast<float>(in_w - 1) / (out_w - 1)
+                                : static_cast<float>(in_w) / out_w;
+    }
 
     if (in_h == out_h && in_w == out_w) {
       framework::TensorCopy(*output_grad, ctx.GetPlace(), input_grad);
@@ -270,12 +318,12 @@ class InterpolateGradOpCUDAKernel : public framework::OpKernel<T> {
       KeNearestNeighborInterpBw<
           T><<<grid_dim, 512, 0, ctx.cuda_device_context().stream()>>>(
           input_grad_data, in_h, in_w, n, in_chw, output_grad_data, out_h,
-          out_w, n, out_chw, c, ratio_h, ratio_w);
+          out_w, n, out_chw, c, ratio_h, ratio_w, align_corners);
     } else if ("bilinear" == interp_method) {
       KeBilinearInterpBw<
           T><<<grid_dim, 512, 0, ctx.cuda_device_context().stream()>>>(
           input_grad_data, in_h, in_w, n, in_chw, output_grad_data, out_h,
-          out_w, n, out_chw, c, ratio_h, ratio_w);
+          out_w, n, out_chw, c, ratio_h, ratio_w, align_corners, align_mode);
     }
   }
 };

paddle/fluid/operators/interpolate_op.h

@@ -26,14 +26,17 @@ template <typename T>
 static void NearestNeighborInterpolate(const Tensor& input, Tensor* output,
                                        const float ratio_h, const float ratio_w,
                                        const int n, const int c,
-                                       const int out_h, const int out_w) {
+                                       const int out_h, const int out_w,
+                                       const bool align_corners) {
   auto input_t = EigenTensor<T, 4>::From(input);
   auto output_t = EigenTensor<T, 4>::From(*output);
   for (int k = 0; k < out_h; k++) {  // loop for images
-    int in_k = static_cast<int>(ratio_h * k + 0.5);
+    int in_k = (align_corners) ? static_cast<int>(ratio_h * k + 0.5)
+                               : static_cast<int>(ratio_h * k);
 
     for (int l = 0; l < out_w; l++) {
-      int in_l = static_cast<int>(ratio_w * l + 0.5);
+      int in_l = (align_corners) ? static_cast<int>(ratio_w * l + 0.5)
+                                 : static_cast<int>(ratio_w * l);
 
       for (int i = 0; i < n; i++) {    // loop for batches
         for (int j = 0; j < c; j++) {  // loop for channels
@@ -48,20 +51,29 @@ template <typename T>
 static void BilinearInterpolation(const Tensor& input, Tensor* output,
                                   const float ratio_h, const float ratio_w,
                                   const int in_h, const int in_w, const int n,
-                                  const int c, const int out_h,
-                                  const int out_w) {
+                                  const int c, const int out_h, const int out_w,
+                                  const bool align_corners,
+                                  const bool align_mode) {
   auto input_t = EigenTensor<T, 4>::From(input);
   auto output_t = EigenTensor<T, 4>::From(*output);
+  bool align_flag = (align_mode == 0 && !align_corners);
   for (int k = 0; k < out_h; k++) {  // loop for images
-    int y_n = static_cast<int>(ratio_h * k);
+    int y_n = align_flag ? static_cast<int>(ratio_h * (k + 0.5) - 0.5)
+                         : static_cast<int>(ratio_h * k);
+    y_n = (y_n > 0) ? y_n : 0;
     int y_s = (y_n + 1) < (in_h - 1) ? (y_n + 1) : (in_h - 1);
-    float d_n = ratio_h * k - y_n;
+    float d_n =
+        align_flag ? ratio_h * (k + 0.5) - 0.5 - y_n : ratio_h * k - y_n;
     float d_s = 1.f - d_n;
 
     for (int l = 0; l < out_w; l++) {
-      int x_w = static_cast<int>(ratio_w * l);
+      int x_w = (align_mode == 0 && !align_corners)
+                    ? static_cast<int>(ratio_w * (l + 0.5) - 0.5)
+                    : static_cast<int>(ratio_w * l);
+      x_w = (x_w > 0) ? x_w : 0;
       int x_e = (x_w + 1) < (in_w - 1) ? (x_w + 1) : (in_w - 1);
-      float d_w = ratio_w * l - x_w;
+      float d_w =
+          align_flag ? ratio_w * (l + 0.5) - 0.5 - x_w : ratio_w * l - x_w;
       float d_e = 1.f - d_w;
 
       for (int i = 0; i < n; i++) {    // loop for batches
@@ -78,19 +90,20 @@ static void BilinearInterpolation(const Tensor& input, Tensor* output,
 }
 
 template <typename T>
-static void NearestNeighborInterpolateGrad(const Tensor& output_grad,
-                                           Tensor* input_grad,
-                                           const float ratio_h,
-                                           const float ratio_w, const int n,
-                                           const int c, const int out_h,
-                                           const int out_w) {
+static void NearestNeighborInterpolateGrad(
+    const Tensor& output_grad, Tensor* input_grad, const float ratio_h,
+    const float ratio_w, const int n, const int c, const int out_h,
+    const int out_w, const bool align_corners) {
   auto input_grad_t = EigenTensor<T, 4>::From(*input_grad);
   auto output_grad_t = EigenTensor<T, 4>::From(output_grad);
+
   for (int k = 0; k < out_h; k++) {  // loop for images
-    int in_k = static_cast<int>(ratio_h * k + 0.5);
+    int in_k = (align_corners) ? static_cast<int>(ratio_h * k + 0.5)
+                               : static_cast<int>(ratio_h * k);
 
     for (int l = 0; l < out_w; l++) {
-      int in_l = static_cast<int>(ratio_w * l + 0.5);
+      int in_l = (align_corners) ? static_cast<int>(ratio_w * l + 0.5)
+                                 : static_cast<int>(ratio_w * l);
 
       for (int i = 0; i < n; i++) {    // loop for batches
         for (int j = 0; j < c; j++) {  // loop for channels
@@ -106,19 +119,28 @@ static void BilinearInterpolationGrad(const Tensor& output_grad,
                                       Tensor* input_grad, const float ratio_h,
                                       const float ratio_w, const int in_h,
                                       const int in_w, const int n, const int c,
-                                      const int out_h, const int out_w) {
+                                      const int out_h, const int out_w,
+                                      const bool align_corners,
+                                      const int align_mode) {
   auto input_grad_t = EigenTensor<T, 4>::From(*input_grad);
   auto output_grad_t = EigenTensor<T, 4>::From(output_grad);
+  bool align_flag = (align_mode == 0 && !align_corners);
   for (int k = 0; k < out_h; k++) {  // loop for images
-    int y_n = static_cast<int>(ratio_h * k);
+    int y_n = align_flag ? static_cast<int>(ratio_h * (k + 0.5) - 0.5)
+                         : static_cast<int>(ratio_h * k);
+    y_n = (y_n > 0) ? y_n : 0;
     int y_s = (y_n + 1) < (in_h - 1) ? (y_n + 1) : (in_h - 1);
-    float d_n = ratio_h * k - y_n;
+    float d_n =
+        align_flag ? ratio_h * (k + 0.5) - 0.5 - y_n : ratio_h * k - y_n;
     float d_s = 1.f - d_n;
 
     for (int l = 0; l < out_w; l++) {
-      int x_w = static_cast<int>(ratio_w * l);
+      int x_w = align_flag ? static_cast<int>(ratio_w * (l + 0.5) - 0.5)
+                           : static_cast<int>(ratio_w * l);
+      x_w = (x_w > 0) ? x_w : 0;
       int x_e = (x_w + 1) < (in_w - 1) ? (x_w + 1) : (in_w - 1);
-      float d_w = ratio_w * l - x_w;
+      float d_w =
+          align_flag ? ratio_w * (l + 0.5) - 0.5 - x_w : ratio_w * l - x_w;
       float d_e = 1.f - d_w;
 
       for (int i = 0; i < n; i++) {    // loop for batches
@@ -134,7 +156,6 @@ static void BilinearInterpolationGrad(const Tensor& output_grad,
     }
   }
 }
-
 template <typename T>
 class InterpolateKernel : public framework::OpKernel<T> {
  public:
@@ -151,6 +172,8 @@ class InterpolateKernel : public framework::OpKernel<T> {
       out_h = out_size_data[0];
       out_w = out_size_data[1];
     }
+    bool align_corners = ctx.Attr<bool>("align_corners");
+    int align_mode = ctx.Attr<int>("align_mode");
 
     const int n = input->dims()[0];
     const int c = input->dims()[1];
@@ -168,17 +191,24 @@ class InterpolateKernel : public framework::OpKernel<T> {
       return;
     }
 
-    float ratio_h =
-        (out_h > 1) ? static_cast<float>(in_h - 1) / (out_h - 1) : 0.f;
-    float ratio_w =
-        (out_w > 1) ? static_cast<float>(in_w - 1) / (out_w - 1) : 0.f;
+    float ratio_h = 0.f;
+    float ratio_w = 0.f;
+
+    if (out_h > 1) {
+      ratio_h = (align_corners) ? static_cast<float>(in_h - 1) / (out_h - 1)
+                                : static_cast<float>(in_h) / out_h;
+    }
+    if (out_w > 1) {
+      ratio_w = (align_corners) ? static_cast<float>(in_w - 1) / (out_w - 1)
+                                : static_cast<float>(in_w) / out_w;
+    }
 
     if ("bilinear" == interp_method) {
       BilinearInterpolation<T>(*input, output, ratio_h, ratio_w, in_h, in_w, n,
-                               c, out_h, out_w);
+                               c, out_h, out_w, align_corners, align_mode);
     } else if ("nearest" == interp_method) {
       NearestNeighborInterpolate<T>(*input, output, ratio_h, ratio_w, n, c,
-                                    out_h, out_w);
+                                    out_h, out_w, align_corners);
     }
   }
 };
@@ -200,6 +230,8 @@ class InterpolateGradKernel : public framework::OpKernel<T> {
       out_h = out_size_data[0];
       out_w = out_size_data[1];
     }
+    bool align_corners = ctx.Attr<bool>("align_corners");
+    int align_mode = ctx.Attr<int>("align_mode");
 
     const int n = input->dims()[0];
     const int c = input->dims()[1];
@@ -217,17 +249,26 @@ class InterpolateGradKernel : public framework::OpKernel<T> {
       return;
     }
 
-    float ratio_h =
-        (out_h > 1) ? static_cast<float>(in_h - 1) / (out_h - 1) : 0.f;
-    float ratio_w =
-        (out_w > 1) ? static_cast<float>(in_w - 1) / (out_w - 1) : 0.f;
+    float ratio_h = 0.f;
+    float ratio_w = 0.f;
+
+    if (out_h > 1) {
+      ratio_h = (align_corners) ? static_cast<float>(in_h - 1) / (out_h - 1)
+                                : static_cast<float>(in_h) / out_h;
+    }
+    if (out_w > 1) {
+      ratio_w = (align_corners) ? static_cast<float>(in_w - 1) / (out_w - 1)
+                                : static_cast<float>(in_w) / out_w;
+    }
 
     if ("bilinear" == interp_method) {
       BilinearInterpolationGrad<T>(*output_grad, input_grad, ratio_h, ratio_w,
-                                   in_h, in_w, n, c, out_h, out_w);
+                                   in_h, in_w, n, c, out_h, out_w,
+                                   align_corners, align_mode);
     } else if ("nearest" == interp_method) {
       NearestNeighborInterpolateGrad<T>(*output_grad, input_grad, ratio_h,
-                                        ratio_w, n, c, out_h, out_w);
+                                        ratio_w, n, c, out_h, out_w,
+                                        align_corners);
     }
   }
 };

python/paddle/fluid/layers/nn.py

@@ -932,7 +932,7 @@ def dynamic_gru(input,
             create ParamAttr as param_attr. If the Initializer of the param_attr
             is not set, the parameter is initialized with Xavier. Default: None.
         bias_attr (ParamAttr|bool|None): The parameter attribute for the bias
-            of GRU. Note that the bias with :math:`(1 \\times 3D)` concatenates
+            of GRU.Note that the bias with :math:`(1 \\times 3D)` concatenates
             the bias in the update gate, reset gate and candidate calculations.
             If it is set to False, no bias will be applied to the update gate,
             reset gate and candidate calculations. If it is set to None or one
@@ -1073,7 +1073,7 @@ def gru_unit(input,
             create ParamAttr as param_attr. If the Initializer of the param_attr
             is not set, the parameter is initialized with Xavier. Default: None.
         bias_attr (ParamAttr|bool|None): The parameter attribute for the bias
-            of GRU. Note that the bias with :math:`(1 \\times 3D)` concatenates
+            of GRU.Note that the bias with :math:`(1 \\times 3D)` concatenates
             the bias in the update gate, reset gate and candidate calculations.
             If it is set to False, no bias will be applied to the update gate,
             reset gate and candidate calculations. If it is set to None or one
@@ -5403,7 +5403,7 @@ def transpose(x, perm, name=None):
     Examples:
         .. code-block:: python
 
-            # use append_batch_size=False to avoid prepending extra
+            # use append_batch_size=False to avoid prepending extra
             # batch size in shape
             x = fluid.layers.data(name='x', shape=[5, 10, 15],
                             dtype='float32', append_batch_size=False)
@@ -5920,7 +5920,7 @@ def reshape(x, shape, actual_shape=None, act=None, inplace=False, name=None):
                                 than :attr:`shape`.
         act (str): The non-linear activation to be applied to the reshaped tensor
                    variable.
-        inplace(bool): Must use :attr:`False` if :attr:`x` is used in multiple
+        inplace(bool): Must use :attr:`False` if :attr:`x` is used in multiple
                        operators. If this flag is set :attr:`True`, reuse input
                        :attr:`x` to reshape, which will change the shape of
                        tensor variable :attr:`x` and might cause errors when
@@ -6581,7 +6581,9 @@ def image_resize(input,
                  scale=None,
                  name=None,
                  resample='BILINEAR',
-                 actual_shape=None):
+                 actual_shape=None,
+                 align_corners=True,
+                 align_mode=1):
     """
     **Resize a Batch of Images**
 
@@ -6594,6 +6596,80 @@ def image_resize(input,
 
         'NEAREST' : Nearest neighbor interpolation
 
+    Nearest neighbor interpolation is to perform nearest neighbor interpolation
+    in both the 3rd dimention(in height direction) and the 4th dimention(in width 
+    direction) on input tensor.
+            
+    Bilinear interpolation is an extension of linear interpolation for 
+    interpolating functions of two variables (e.g. H-direction and 
+    W-direction in this op) on a rectilinear 2D grid. The key idea is 
+    to perform linear interpolation first in one direction, and then 
+    again in the other direction.
+
+    Align_corners and align_mode are optinal parameters,the calculation method 
+    of interpolation can be selected by them.
+
+    Example:
+
+      For scale:
+      
+        if align_corners = True && out_size > 1 :
+
+          scale_factor = (in_size-1.0)/(out_size-1.0)
+        
+        else:
+          
+          scale_factor = float(in_size/out_size)
+        
+      
+      Nearest neighbor interpolation:
+      
+      if:
+          align_corners = False
+
+          input : (N,C,H_in,W_in)
+          output: (N,C,H_out,W_out) where:
+
+          H_out = \left \lfloor {H_{in} * scale_{}factor}} \right \rfloor
+          W_out = \left \lfloor {W_{in} * scale_{}factor}} \right \rfloor
+
+      else:
+          align_corners = True
+
+          input : (N,C,H_in,W_in)
+          output: (N,C,H_out,W_out) where:
+
+          H_out = round(H_{in} * scale_{factor})
+          W_out = round(W_{in} * scale_{factor})
+
+      Bilinear interpolation:
+
+      if:
+          align_corners = False , align_mode = 0
+          
+          input : (N,C,H_in,W_in)
+          output: (N,C,H_out,W_out) where:
+          
+          H_out = (H_{in}+0.5) * scale_{factor} - 0.5
+          W_out = (W_{in}+0.5) * scale_{factor} - 0.5
+
+
+      else:
+       
+          input : (N,C,H_in,W_in)
+          output: (N,C,H_out,W_out) where:
+
+          H_out = H_{in} * scale_{factor}
+          W_out = W_{in} * scale_{factor}
+
+    For details of nearest neighbor interpolation, please refer to Wikipedia: 
+    https://en.wikipedia.org/wiki/Nearest-neighbor_interpolation.
+
+    For details of bilinear interpolation, please refer to Wikipedia: 
+    https://en.wikipedia.org/wiki/Bilinear_interpolation.
+
+
+
     Args:
         input (Variable): The input tensor of image resize layer,
                           This is a 4-D tensor of the shape
@@ -6623,6 +6699,13 @@ def image_resize(input,
                                 set, otherwise errors would be occured in graph
                                 constructing stage.
                                 Default: None
+        align_corners(bool) :  An optional bool, If True, the centers of the 4 corner pixels of the 
+                               input and output tensors are aligned, preserving the values at the 
+                               corner pixels.
+                               Default: True
+        align_mode(int)  :  An optional for bilinear interpolation. can be \'0\' 
+                            for src_idx = scale*(dst_indx+0.5)-0.5 , can be \'1\' for 
+                            src_idx = scale*dst_index .
 
     Returns:
         Variable: The output is a 4-D tensor of the shape
@@ -6635,6 +6718,8 @@ def image_resize(input,
                     or 'NEAREST' currently.
         ValueError: One of out_shape and scale must not be None.
         ValueError: out_shape length should be 2.
+        TypeError: align_corners shoule be a bool value
+        ValueError: align_mode can only be '0' or '1'
 
     Examples:
         .. code-block:: python
@@ -6650,6 +6735,12 @@ def image_resize(input,
             "The 'resample' of image_resize can only be 'BILINEAR' or 'NEAREST' currently."
         )
     resample_type = resample_methods[resample]
+
+    if not isinstance(align_corners, bool):
+        raise TypeError("Attr align_corners should be a bool value")
+    if align_mode != 0 and align_mode != 1:
+        raise ValueError("align_mode can only be 0 or 1")
+
     if out_shape is None and scale is None:
         raise ValueError("One of out_shape and scale must not be None.")
     helper = LayerHelper('{}_interp'.format(resample_type), **locals())
@@ -6689,9 +6780,13 @@ def image_resize(input,
         type='{}_interp'.format(resample_type),
         inputs=inputs,
         outputs={"Out": out},
-        attrs={"out_h": out_h,
+        attrs={
+            "out_h": out_h,
             "out_w": out_w,
-               "interp_method": resample_type})
+            "interp_method": resample_type,
+            "align_corners": align_corners,
+            "align_mode": align_mode
+        })
     return out
 
 
@@ -6700,7 +6795,9 @@ def resize_bilinear(input,
                     out_shape=None,
                     scale=None,
                     name=None,
-                    actual_shape=None):
+                    actual_shape=None,
+                    align_corners=True,
+                    align_mode=1):
     """
     Resize input by performing bilinear interpolation based on given
     output shape which specified by actual_shape, out_shape and scale
@@ -6715,6 +6812,47 @@ def resize_bilinear(input,
     For details of bilinear interpolation, please refer to Wikipedia:
     https://en.wikipedia.org/wiki/Bilinear_interpolation
 
+    Align_corners and align_mode are optinal parameters,the calculation 
+    method of interpolation can be selected by them.
+
+
+    Align_corners and align_mode are optinal parameters,the calculation method 
+    of interpolation can be selected by them.
+
+    Example:
+
+      For scale:
+      
+        if align_corners = True && out_size > 1 :
+
+          scale_factor = (in_size-1.0)/(out_size-1.0)
+        
+        else:
+          
+          scale_factor = float(in_size/out_size)     
+
+    Bilinear interpolation:
+
+      if:
+          align_corners = False , align_mode = 0
+          
+          input : (N,C,H_in,W_in)
+          output: (N,C,H_out,W_out) where:
+          
+          H_out = (H_{in}+0.5) * scale_{factor} - 0.5
+          W_out = (W_{in}+0.5) * scale_{factor} - 0.5
+
+
+      else:
+
+          input : (N,C,H_in,W_in)
+          output: (N,C,H_out,W_out) where:
+
+          H_out = H_{in} * scale_{factor}
+          W_out = W_{in} * scale_{factor}
+
+
+
     Args:
         input(${x_type}): ${x_comment}.
 
@@ -6738,6 +6876,8 @@ def resize_bilinear(input,
                                 set, otherwise errors would be occured in graph
                                 constructing stage.
                                 Default: None
+        align_corners(bool): ${align_corners_comment}
+        align_mode(bool): ${align_mode_comment}
 
     Returns:
         ${out_comment}.
@@ -6748,7 +6888,8 @@ def resize_bilinear(input,
             out = fluid.layers.resize_bilinear(input, out_shape=[12, 12])
     """
 
-    return image_resize(input, out_shape, scale, name, 'BILINEAR', actual_shape)
+    return image_resize(input, out_shape, scale, name, 'BILINEAR', actual_shape,
+                        align_corners, align_mode)
 
 
 @templatedoc(op_type="nearest_interp")
@@ -6756,13 +6897,48 @@ def resize_nearest(input,
                    out_shape=None,
                    scale=None,
                    name=None,
-                   actual_shape=None):
+                   actual_shape=None,
+                   align_corners=True):
     """
     Resize input by performing nearest neighbor interpolation in both the
     3rd dimention(in height direction) and the 4th dimention(in width
     direction) based on given output shape which specified by actual_shape,
     out_shape and scale in priority order.
 
+    Example:
+
+      For scale:
+      
+        if align_corners = True && out_size > 1 :
+
+          scale_factor = (in_size-1.0)/(out_size-1.0)
+        
+        else:
+          
+          scale_factor = float(in_size/out_size)
+        
+      
+      Nearest neighbor interpolation:
+      
+      if:
+          align_corners = False
+
+          input : (N,C,H_in,W_in)
+          output: (N,C,H_out,W_out) where:
+
+          H_out = \left \lfloor {H_{in} * scale_{}factor}} \right \rfloor
+          W_out = \left \lfloor {W_{in} * scale_{}factor}} \right \rfloor
+
+      else:
+          align_corners = True
+
+          input : (N,C,H_in,W_in)
+          output: (N,C,H_out,W_out) where:
+
+          H_out = round(H_{in} * scale_{factor})
+          W_out = round(W_{in} * scale_{factor})
+
+
     For details of nearest neighbor interpolation, please refer to Wikipedia:
     https://en.wikipedia.org/wiki/Nearest-neighbor_interpolation
 
@@ -6789,6 +6965,7 @@ def resize_nearest(input,
                                 set, otherwise errors would be occured in graph
                                 constructing stage.
                                 Default: None
+        align_corners(bool): ${align_corners_comment}
 
     Returns:
         ${out_comment}.
@@ -6799,7 +6976,8 @@ def resize_nearest(input,
             out = fluid.layers.resize_nearest(input, out_shape=[12, 12])
     """
 
-    return image_resize(input, out_shape, scale, name, 'NEAREST', actual_shape)
+    return image_resize(input, out_shape, scale, name, 'NEAREST', actual_shape,
+                        align_corners)
 
 
 def image_resize_short(input, out_short_len, resample='BILINEAR'):

python/paddle/fluid/tests/unittests/test_bilinear_interp_op.py

@@ -20,7 +20,13 @@ from op_test import OpTest
 import paddle.fluid.core as core
 
 
-def bilinear_interp_np(input, out_h, out_w, out_size=None, actual_shape=None):
+def bilinear_interp_np(input,
+                       out_h,
+                       out_w,
+                       out_size=None,
+                       actual_shape=None,
+                       align_corners=True,
+                       align_mode=0):
     """bilinear interpolation implement in shape [N, C, H, W]"""
     if out_size is not None:
         out_h = out_size[0]
@@ -29,24 +35,44 @@ def bilinear_interp_np(input, out_h, out_w, out_size=None, actual_shape=None):
         out_h = actual_shape[0]
         out_w = actual_shape[1]
     batch_size, channel, in_h, in_w = input.shape
+
+    ratio_h = ratio_w = 0.0
     if out_h > 1:
+        if (align_corners):
             ratio_h = (in_h - 1.0) / (out_h - 1.0)
         else:
-        ratio_h = 0.0
+            ratio_h = 1.0 * in_h / out_h
     if out_w > 1:
+        if (align_corners):
             ratio_w = (in_w - 1.0) / (out_w - 1.0)
         else:
-        ratio_w = 0.0
+            ratio_w = 1.0 * in_w / out_w
 
     out = np.zeros((batch_size, channel, out_h, out_w))
+
     for i in range(out_h):
+        if (align_mode == 0 and not align_corners):
+            h = int(ratio_h * (i + 0.5) - 0.5)
+        else:
             h = int(ratio_h * i)
+
+        h = max(0, h)
         hid = 1 if h < in_h - 1 else 0
+        if (align_mode == 0 and not align_corners):
+            h1lambda = ratio_h * (i + 0.5) - 0.5 - h
+        else:
             h1lambda = ratio_h * i - h
         h2lambda = 1.0 - h1lambda
         for j in range(out_w):
+            if (align_mode == 0 and not align_corners):
+                w = int(ratio_w * (j + 0.5) - 0.5)
+            else:
                 w = int(ratio_w * j)
+            w = max(0, w)
             wid = 1 if w < in_w - 1 else 0
+            if (align_mode == 0 and not align_corners):
+                w1lambda = ratio_w * (j + 0.5) - 0.5 - w
+            else:
                 w1lambda = ratio_w * j - w
             w2lambda = 1.0 - w1lambda
 
@@ -66,7 +92,8 @@ class TestBilinearInterpOp(OpTest):
         input_np = np.random.random(self.input_shape).astype("float32")
 
         output_np = bilinear_interp_np(input_np, self.out_h, self.out_w,
-                                       self.out_size, self.actual_shape)
+                                       self.out_size, self.actual_shape,
+                                       self.align_corners, self.align_mode)
         self.inputs = {'X': input_np}
         if self.out_size is not None:
             self.inputs['OutSize'] = self.out_size
@@ -75,7 +102,9 @@ class TestBilinearInterpOp(OpTest):
         self.attrs = {
             'out_h': self.out_h,
             'out_w': self.out_w,
-            'interp_method': self.interp_method
+            'interp_method': self.interp_method,
+            'align_corners': self.align_corners,
+            'align_mode': self.align_mode
         }
         self.outputs = {'Out': output_np}
 
@@ -91,6 +120,8 @@ class TestBilinearInterpOp(OpTest):
         self.out_h = 2
         self.out_w = 2
         self.out_size = np.array([3, 3]).astype("int32")
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpCase1(TestBilinearInterpOp):
@@ -99,6 +130,8 @@ class TestBilinearInterpCase1(TestBilinearInterpOp):
         self.input_shape = [4, 1, 7, 8]
         self.out_h = 1
         self.out_w = 1
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpCase2(TestBilinearInterpOp):
@@ -107,6 +140,8 @@ class TestBilinearInterpCase2(TestBilinearInterpOp):
         self.input_shape = [3, 3, 9, 6]
         self.out_h = 12
         self.out_w = 12
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpCase3(TestBilinearInterpOp):
@@ -115,6 +150,8 @@ class TestBilinearInterpCase3(TestBilinearInterpOp):
         self.input_shape = [1, 1, 128, 64]
         self.out_h = 64
         self.out_w = 128
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpCase4(TestBilinearInterpOp):
@@ -124,6 +161,8 @@ class TestBilinearInterpCase4(TestBilinearInterpOp):
         self.out_h = 1
         self.out_w = 1
         self.out_size = np.array([2, 2]).astype("int32")
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpCase5(TestBilinearInterpOp):
@@ -133,6 +172,8 @@ class TestBilinearInterpCase5(TestBilinearInterpOp):
         self.out_h = 12
         self.out_w = 12
         self.out_size = np.array([11, 11]).astype("int32")
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpCase6(TestBilinearInterpOp):
@@ -142,6 +183,8 @@ class TestBilinearInterpCase6(TestBilinearInterpOp):
         self.out_h = 64
         self.out_w = 128
         self.out_size = np.array([65, 129]).astype("int32")
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpActualShape(TestBilinearInterpOp):
@@ -151,6 +194,8 @@ class TestBilinearInterpActualShape(TestBilinearInterpOp):
         self.out_h = 64
         self.out_w = 32
         self.out_size = np.array([66, 40]).astype("int32")
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpOpUint8(OpTest):
@@ -162,14 +207,17 @@ class TestBilinearInterpOpUint8(OpTest):
         input_np = np.random.randint(
             low=0, high=256, size=self.input_shape).astype("uint8")
         output_np = bilinear_interp_np(input_np, self.out_h, self.out_w,
-                                       self.out_size, self.actual_shape)
+                                       self.out_size, self.actual_shape,
+                                       self.align_corners, self.align_mode)
         self.inputs = {'X': input_np}
         if self.out_size is not None:
             self.inputs['OutSize'] = self.out_size
         self.attrs = {
             'out_h': self.out_h,
             'out_w': self.out_w,
-            'interp_method': self.interp_method
+            'interp_method': self.interp_method,
+            'align_corners': self.align_corners,
+            'align_mode': self.align_mode
         }
         self.outputs = {'Out': output_np}
 
@@ -181,6 +229,8 @@ class TestBilinearInterpOpUint8(OpTest):
         self.input_shape = [1, 3, 9, 6]
         self.out_h = 10
         self.out_w = 9
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpCase1Uint8(TestBilinearInterpOpUint8):
@@ -189,6 +239,8 @@ class TestBilinearInterpCase1Uint8(TestBilinearInterpOpUint8):
         self.input_shape = [2, 3, 128, 64]
         self.out_h = 120
         self.out_w = 50
+        self.align_corners = True
+        self.align_mode = 1
 
 
 class TestBilinearInterpCase2Uint8(TestBilinearInterpOpUint8):
@@ -198,6 +250,26 @@ class TestBilinearInterpCase2Uint8(TestBilinearInterpOpUint8):
         self.out_h = 5
         self.out_w = 13
         self.out_size = np.array([6, 15]).astype("int32")
+        self.align_corners = True
+        self.align_mode = 1
+
+
+class TestBilinearInterpOtherMethod1(TestBilinearInterpOp):
+    def set_align_mode(self):
+        self.align_corners = False
+        self.align_mode = 1
+
+
+class TestBilinearInterpWithMethod2(TestBilinearInterpOp):
+    def set_align_mode(self):
+        self.align_corners = False
+        self.align_mode = 0
+
+
+class TestBilinearInterpWithMethod3(TestBilinearInterpOp):
+    def set_align_mode(self):
+        self.align_corners = True
+        self.align_mode = 0
 
 
 if __name__ == "__main__":

python/paddle/fluid/tests/unittests/test_nearest_interp_op.py

@@ -24,7 +24,8 @@ def nearest_neighbor_interp_np(X,
                                out_h,
                                out_w,
                                out_size=None,
-                               actual_shape=None):
+                               actual_shape=None,
+                               align_corners=True):
     """nearest neighbor interpolation implement in shape [N, C, H, W]"""
     if out_size is not None:
         out_h = out_size[0]
@@ -35,17 +36,31 @@ def nearest_neighbor_interp_np(X,
     n, c, in_h, in_w = X.shape
 
     ratio_h = ratio_w = 0.0
-    if out_h > 1:
+    if (out_h > 1):
+        if (align_corners):
             ratio_h = (in_h - 1.0) / (out_h - 1.0)
-    if out_w > 1:
+        else:
+            ratio_h = 1.0 * in_h / out_h
+    if (out_w > 1):
+        if (align_corners):
             ratio_w = (in_w - 1.0) / (out_w - 1.0)
+        else:
+            ratio_w = 1.0 * in_w / out_w
 
     out = np.zeros((n, c, out_h, out_w))
+
+    if align_corners:
         for i in range(out_h):
             in_i = int(ratio_h * i + 0.5)
             for j in range(out_w):
                 in_j = int(ratio_w * j + 0.5)
                 out[:, :, i, j] = X[:, :, in_i, in_j]
+    else:
+        for i in range(out_h):
+            in_i = int(ratio_h * i)
+            for j in range(out_w):
+                in_j = int(ratio_w * j)
+                out[:, :, i, j] = X[:, :, in_i, in_j]
 
     return out.astype(X.dtype)
 
@@ -59,7 +74,8 @@ class TestNearestInterpOp(OpTest):
         input_np = np.random.random(self.input_shape).astype("float32")
 
         output_np = nearest_neighbor_interp_np(input_np, self.out_h, self.out_w,
-                                               self.out_size, self.actual_shape)
+                                               self.out_size, self.actual_shape,
+                                               self.align_corners)
         self.inputs = {'X': input_np}
         if self.out_size is not None:
             self.inputs['OutSize'] = self.out_size
@@ -68,7 +84,8 @@ class TestNearestInterpOp(OpTest):
         self.attrs = {
             'out_h': self.out_h,
             'out_w': self.out_w,
-            'interp_method': self.interp_method
+            'interp_method': self.interp_method,
+            'align_corners': self.align_corners,
         }
         self.outputs = {'Out': output_np}
 
@@ -84,6 +101,7 @@ class TestNearestInterpOp(OpTest):
         self.out_h = 2
         self.out_w = 2
         self.out_size = np.array([3, 3]).astype("int32")
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpCase1(TestNearestInterpOp):
@@ -92,6 +110,7 @@ class TestNearestNeighborInterpCase1(TestNearestInterpOp):
         self.input_shape = [4, 1, 7, 8]
         self.out_h = 1
         self.out_w = 1
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpCase2(TestNearestInterpOp):
@@ -100,6 +119,7 @@ class TestNearestNeighborInterpCase2(TestNearestInterpOp):
         self.input_shape = [3, 3, 9, 6]
         self.out_h = 12
         self.out_w = 12
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpCase3(TestNearestInterpOp):
@@ -108,6 +128,7 @@ class TestNearestNeighborInterpCase3(TestNearestInterpOp):
         self.input_shape = [1, 1, 128, 64]
         self.out_h = 64
         self.out_w = 128
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpCase4(TestNearestInterpOp):
@@ -117,6 +138,7 @@ class TestNearestNeighborInterpCase4(TestNearestInterpOp):
         self.out_h = 1
         self.out_w = 1
         self.out_size = np.array([2, 2]).astype("int32")
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpCase5(TestNearestInterpOp):
@@ -126,6 +148,7 @@ class TestNearestNeighborInterpCase5(TestNearestInterpOp):
         self.out_h = 12
         self.out_w = 12
         self.out_size = np.array([11, 11]).astype("int32")
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpCase6(TestNearestInterpOp):
@@ -135,6 +158,7 @@ class TestNearestNeighborInterpCase6(TestNearestInterpOp):
         self.out_h = 64
         self.out_w = 128
         self.out_size = np.array([65, 129]).astype("int32")
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpActualShape(TestNearestInterpOp):
@@ -144,6 +168,7 @@ class TestNearestNeighborInterpActualShape(TestNearestInterpOp):
         self.out_h = 64
         self.out_w = 32
         self.out_size = np.array([66, 40]).astype("int32")
+        self.align_corners = True
 
 
 class TestNearestInterpOpUint8(OpTest):
@@ -155,14 +180,16 @@ class TestNearestInterpOpUint8(OpTest):
         input_np = np.random.randint(
             low=0, high=256, size=self.input_shape).astype("uint8")
         output_np = nearest_neighbor_interp_np(input_np, self.out_h, self.out_w,
-                                               self.out_size, self.actual_shape)
+                                               self.out_size, self.actual_shape,
+                                               self.align_corners)
         self.inputs = {'X': input_np}
         if self.out_size is not None:
             self.inputs['OutSize'] = self.out_size
         self.attrs = {
             'out_h': self.out_h,
             'out_w': self.out_w,
-            'interp_method': self.interp_method
+            'interp_method': self.interp_method,
+            'align_corners': self.align_corners
         }
         self.outputs = {'Out': output_np}
 
@@ -174,6 +201,7 @@ class TestNearestInterpOpUint8(OpTest):
         self.input_shape = [1, 3, 9, 6]
         self.out_h = 10
         self.out_w = 9
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpCase1Uint8(TestNearestInterpOpUint8):
@@ -182,6 +210,7 @@ class TestNearestNeighborInterpCase1Uint8(TestNearestInterpOpUint8):
         self.input_shape = [2, 3, 128, 64]
         self.out_h = 120
         self.out_w = 50
+        self.align_corners = True
 
 
 class TestNearestNeighborInterpCase2Uint8(TestNearestInterpOpUint8):
@@ -191,6 +220,12 @@ class TestNearestNeighborInterpCase2Uint8(TestNearestInterpOpUint8):
         self.out_h = 5
         self.out_w = 13
         self.out_size = np.array([6, 15]).astype("int32")
+        self.align_corners = True
+
+
+class TestNearestInterpWithoutCorners(TestNearestInterpOp):
+    def set_align_corners(self):
+        self.align_corners = False
 
 
 if __name__ == "__main__":