COMPMID-661: issue# 23 Scale border fix (#26)

Changes in CL and reference in terms of border handling.

Change-Id: I5bed95b1f4c308629d7113455dc8a55d74500bcd
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/95742
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>

2 files changed, 26 insertions, 21 deletions

diff --git a/tests/validation/CPP/Scale.cpp b/tests/validation/CPP/Scale.cpp
index 74489aaa96..0da7497277 100644
--- a/tests/validation/CPP/Scale.cpp
+++ b/tests/validation/CPP/Scale.cpp
@@ -50,6 +50,9 @@ SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, I
     const auto width  = static_cast<int>(in.shape().x());
     const auto height = static_cast<int>(in.shape().y());
 
+    // Determine border size
+    const int border_size = (border_mode == BorderMode::UNDEFINED) ? 0 : 1;
+
     // Area interpolation behaves as Nearest Neighbour in case of up-sampling
     if(policy == InterpolationPolicy::AREA && wr <= 1.f && hr <= 1.f)
     {
@@ -75,30 +78,17 @@ SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, I
                 id.set(1, y_src);
 
                 // If coordinates in range of tensor's width or height
-                if(x_src >= -1 || y_src >= -1 || x_src <= width || y_src <= height)
+                if(is_valid_pixel_index(x_src, y_src, width, height, border_size))
                 {
                     out[element_idx] = tensor_elem_at(in, id, border_mode, constant_border_value);
                 }
-                else
-                {
-                    if(border_mode == BorderMode::CONSTANT)
-                    {
-                        out[element_idx] = constant_border_value;
-                    }
-                    else if(border_mode == BorderMode::REPLICATE)
-                    {
-                        id.set(0, clamp(static_cast<int>(x_src), 0, width - 1));
-                        id.set(1, clamp(static_cast<int>(y_src), 0, height - 1));
-                        out[element_idx] = in[coord2index(in.shape(), id)];
-                    }
-                }
                 break;
             }
             case InterpolationPolicy::BILINEAR:
             {
                 id.set(0, std::floor(x_src));
                 id.set(1, std::floor(y_src));
-                if(x_src >= -1 || y_src >= -1 || x_src <= width || y_src <= height)
+                if(is_valid_pixel_index(x_src, y_src, width, height, border_size))
                 {
                     out[element_idx] = bilinear_policy(in, id, x_src, y_src, border_mode, constant_border_value);
                 }
@@ -127,14 +117,14 @@ SimpleTensor<T> scale(const SimpleTensor<T> &in, float scale_x, float scale_y, I
                 const int yi     = std::floor(y_src);
 
                 // Clamp position to borders
-                x_src = std::max(-1.f, std::min(x_src, static_cast<float>(width)));
-                y_src = std::max(-1.f, std::min(y_src, static_cast<float>(height)));
+                x_src = std::max(-static_cast<float>(border_size), std::min(x_src, static_cast<float>(width - 1 + border_size)));
+                y_src = std::max(-static_cast<float>(border_size), std::min(y_src, static_cast<float>(height - 1 + border_size)));
 
                 // Clamp bounding box offsets to borders
-                x_from = ((x_src + x_from) < -1) ? -1 : x_from;
-                y_from = ((y_src + y_from) < -1) ? -1 : y_from;
-                x_to   = ((x_src + x_to) > width) ? (width - x_src) : x_to;
-                y_to   = ((y_src + y_to) > height) ? (height - y_src) : y_to;
+                x_from = ((x_src + x_from) < -border_size) ? -border_size : x_from;
+                y_from = ((y_src + y_from) < -border_size) ? -border_size : y_from;
+                x_to   = ((x_src + x_to) >= (width + border_size)) ? (width - 1 + border_size) : x_to;
+                y_to   = ((y_src + y_to) >= (height + border_size)) ? (height - 1 + border_size) : y_to;
                 ARM_COMPUTE_ERROR_ON((x_to - x_from + 1) == 0 || (y_to - y_from + 1) == 0);
 
                 float sum = 0;
diff --git a/tests/validation/CPP/Utils.h b/tests/validation/CPP/Utils.h
index 0733411462..2aa77c6ff7 100644
--- a/tests/validation/CPP/Utils.h
+++ b/tests/validation/CPP/Utils.h
@@ -41,6 +41,21 @@ namespace test
 {
 namespace validation
 {
+/** Checks if a pixel has valid coordinates
+ *
+ * @param x            X coordinate
+ * @param y            Y coordinate
+ * @param width        Width of the image
+ * @param height       Height of the image
+ * @param border_size  Border size
+ *
+ * @return True if pixel is valid else false
+ */
+inline bool is_valid_pixel_index(int x, int y, int width, int height, int border_size)
+{
+    return ((x >= -border_size) && (y >= -border_size) && (x < (width + border_size)) && (y < height + border_size));
+}
+
 // Return a tensor element at a specified coordinate with different border modes
 template <typename T>
 T tensor_elem_at(const SimpleTensor<T> &src, Coordinates coord, BorderMode border_mode, T constant_border_value)