COMPMID-661: Fix scale border issue (#38)

Change-Id: If1dcca724e5e5f5ab363ffc16b0ef8c943e0b657
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/110105
Tested-by: BSG Visual Compute Jenkins server to access repositories on http://mpd-gerrit.cambridge.arm.com <bsgcomp@arm.com>
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>

3 files changed, 29 insertions, 9 deletions

diff --git a/tests/validation/CPP/GaussianPyramidHalf.cpp b/tests/validation/CPP/GaussianPyramidHalf.cpp
index 18d3daa288..0a68dedaee 100644
--- a/tests/validation/CPP/GaussianPyramidHalf.cpp
+++ b/tests/validation/CPP/GaussianPyramidHalf.cpp
@@ -51,7 +51,8 @@ std::vector<SimpleTensor<T>> gaussian_pyramid_half(const SimpleTensor<T> &src, B
         const SimpleTensor<T> out_gaus5x5 = reference::gaussian5x5(dst[i - 1], border_mode, constant_border_value);
 
         // Scale down by 2 with nearest interpolation
-        const SimpleTensor<T> out = reference::scale(out_gaus5x5, SCALE_PYRAMID_HALF, SCALE_PYRAMID_HALF, InterpolationPolicy::NEAREST_NEIGHBOR, border_mode, constant_border_value, true);
+        const SimpleTensor<T> out = reference::scale(out_gaus5x5, SCALE_PYRAMID_HALF, SCALE_PYRAMID_HALF, InterpolationPolicy::NEAREST_NEIGHBOR, border_mode, constant_border_value, SamplingPolicy::CENTER,
+                                                     true);
 
         dst.push_back(out);
     }
diff --git a/tests/validation/CPP/Scale.cpp b/tests/validation/CPP/Scale.cpp
index c368fa277a..727325f675 100644
--- a/tests/validation/CPP/Scale.cpp
+++ b/tests/validation/CPP/Scale.cpp
@@ -26,6 +26,7 @@
 
 #include "Scale.h"
 #include "Utils.h"
+#include "support/ToolchainSupport.h"
 
 namespace arm_compute
 {
@@ -36,7 +37,8 @@ namespace validation
 namespace reference
 {
 template <typename T>
-SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, T constant_border_value, bool ceil_policy_scale)
+SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, T constant_border_value,
+                      SamplingPolicy sampling_policy, bool ceil_policy_scale)
 {
     // Add 1 if ceil_policy_scale is true
     const size_t round_value = ceil_policy_scale ? 1U : 0U;
@@ -66,8 +68,23 @@ SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, I
         Coordinates id    = index2coord(out.shape(), element_idx);
         int         idx   = id.x();
         int         idy   = id.y();
-        float       x_src = (idx + 0.5f) * wr - 0.5f;
-        float       y_src = (idy + 0.5f) * hr - 0.5f;
+        float       x_src = 0;
+        float       y_src = 0;
+
+        switch(sampling_policy)
+        {
+            case SamplingPolicy::TOP_LEFT:
+                x_src = idx * wr;
+                y_src = idy * hr;
+                break;
+            case SamplingPolicy::CENTER:
+                x_src = (idx + 0.5f) * wr - 0.5f;
+                y_src = (idy + 0.5f) * hr - 0.5f;
+                break;
+            default:
+                ARM_COMPUTE_ERROR("Unsupported sampling policy.");
+                break;
+        }
 
         switch(policy)
         {
@@ -152,12 +169,13 @@ SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, I
 }
 
 template SimpleTensor<uint8_t> scale(const SimpleTensor<uint8_t> &src, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, uint8_t constant_border_value,
-                                     bool ceil_policy_scale);
+                                     SamplingPolicy sampling_policy, bool ceil_policy_scale);
 template SimpleTensor<int16_t> scale(const SimpleTensor<int16_t> &src, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, int16_t constant_border_value,
-                                     bool ceil_policy_scale);
-template SimpleTensor<half> scale(const SimpleTensor<half> &src, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, half constant_border_value, bool ceil_policy_scale);
+                                     SamplingPolicy sampling_policy, bool ceil_policy_scale);
+template SimpleTensor<half> scale(const SimpleTensor<half> &src, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, half constant_border_value,
+                                  SamplingPolicy sampling_policy, bool ceil_policy_scale);
 template SimpleTensor<float> scale(const SimpleTensor<float> &src, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, float constant_border_value,
-                                   bool ceil_policy_scale);
+                                   SamplingPolicy sampling_policy, bool ceil_policy_scale);
 } // namespace reference
 } // namespace validation
 } // namespace test
diff --git a/tests/validation/CPP/Scale.h b/tests/validation/CPP/Scale.h
index 87af2fd204..566e30af10 100644
--- a/tests/validation/CPP/Scale.h
+++ b/tests/validation/CPP/Scale.h
@@ -35,7 +35,8 @@ namespace validation
 namespace reference
 {
 template <typename T>
-SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, T constant_border_value = 0, bool ceil_policy_scale = false);
+SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, InterpolationPolicy policy, BorderMode border_mode, T constant_border_value = 0,
+                      SamplingPolicy sampling_policy = SamplingPolicy::CENTER, bool ceil_policy_scale = false);
 } // namespace reference
 } // namespace validation
 } // namespace test