COMPMID-344 Updated doxygen

Change-Id: I32f7b84daa560e460b77216add529c8fa8b327ae

1 files changed, 651 insertions, 0 deletions

diff --git a/src/core/NEON/kernels/NEWarpKernel.cpp b/src/core/NEON/kernels/NEWarpKernel.cpp
new file mode 100644
index 0000000000..6c90a334af
--- /dev/null
+++ b/src/core/NEON/kernels/NEWarpKernel.cpp
@@ -0,0 +1,651 @@
+/*
+ * Copyright (c) 2016, 2017 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/core/NEON/kernels/NEWarpKernel.h"
+
+#include "arm_compute/core/AccessWindowStatic.h"
+#include "arm_compute/core/Coordinates.h"
+#include "arm_compute/core/Error.h"
+#include "arm_compute/core/Helpers.h"
+#include "arm_compute/core/ITensor.h"
+#include "arm_compute/core/TensorInfo.h"
+#include "arm_compute/core/Validate.h"
+#include "arm_compute/core/Window.h"
+
+#include <cstddef>
+
+using namespace arm_compute;
+
+namespace
+{
+inline uint8_t nearest_interpolation(const uint8_t *in_ptr, int x, int y, size_t stride)
+{
+    return in_ptr[x + y * stride];
+}
+} // namespace
+
+INEWarpKernel::INEWarpKernel()
+    : _func(nullptr), _input(nullptr), _output(nullptr), _constant_border_value(0), _matrix(nullptr)
+{
+}
+
+void INEWarpKernel::run(const Window &window)
+{
+    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
+    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(INEKernel::window(), window);
+    ARM_COMPUTE_ERROR_ON(_func == nullptr);
+
+    (this->*_func)(window);
+}
+
+void INEWarpKernel::configure(const ITensor *input, ITensor *output, const float *matrix, BorderMode border_mode, uint8_t constant_border_value)
+{
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(input, 1, DataType::U8);
+    ARM_COMPUTE_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(output, 1, DataType::U8);
+    ARM_COMPUTE_ERROR_ON(nullptr == matrix);
+
+    _matrix                = matrix;
+    _constant_border_value = constant_border_value;
+
+    switch(border_mode)
+    {
+        case BorderMode::UNDEFINED:
+            _func = &INEWarpKernel::warp_undefined;
+            break;
+        case BorderMode::CONSTANT:
+            _func = &INEWarpKernel::warp_constant;
+            break;
+        case BorderMode::REPLICATE:
+            _func = &INEWarpKernel::warp_replicate;
+            break;
+        default:
+            ARM_COMPUTE_ERROR("Border mode not supported");
+            break;
+    }
+
+    _input  = input;
+    _output = output;
+
+    // Configure kernel window
+    Window win = calculate_max_window(*output->info(), Steps(1U));
+
+    const ValidRegion &input_valid_region = input->info()->valid_region();
+
+    // Reads can occur within the valid region of the input
+    AccessWindowStatic input_access(input->info(),
+                                    input_valid_region.anchor[0], input_valid_region.anchor[1],
+                                    input_valid_region.anchor[0] + input_valid_region.shape[0],
+                                    input_valid_region.anchor[1] + input_valid_region.shape[1]);
+    AccessWindowHorizontal output_access(output->info(), 0, 1);
+
+    update_window_and_padding(win, input_access, output_access);
+
+    output_access.set_valid_region(win, ValidRegion(Coordinates(), output->info()->tensor_shape()));
+
+    INEKernel::configure(win);
+}
+
+template <InterpolationPolicy interpolation>
+void NEWarpAffineKernel<interpolation>::warp_undefined(const Window &window)
+{
+    // Don't increment in X and Y direction for the input tensor
+    // A pointer to the start of this plane is needed as base for the precomputed offsets
+    Window win_in(window);
+    win_in.set(Window::DimX, Window::Dimension(0, 0, 0));
+    win_in.set(Window::DimY, Window::Dimension(0, 0, 0));
+
+    Iterator in(_input, win_in);
+    Iterator out(_output, window);
+
+    const int    min_x  = _input->info()->valid_region().anchor[0];
+    const int    max_x  = min_x + _input->info()->valid_region().shape[0];
+    const int    min_y  = _input->info()->valid_region().anchor[1];
+    const int    max_y  = min_y + _input->info()->valid_region().shape[1];
+    const size_t stride = _input->info()->strides_in_bytes()[1];
+
+    // x0 = M01 * x + M01 * y + M02
+    // y0 = M11 * x + M11 * y + M12
+    const float M00 = _matrix[0];
+    const float M10 = _matrix[1];
+    const float M01 = _matrix[0 + 1 * 2];
+    const float M11 = _matrix[1 + 1 * 2];
+    const float M02 = _matrix[0 + 2 * 2];
+    const float M12 = _matrix[1 + 2 * 2];
+
+    // "M00 * x" and "M10 * x", when x = window.x.start
+    const float start_x0 = M00 * window.x().start();
+    const float start_y0 = M10 * window.x().start();
+
+    // Current row
+    int y_cur = window.y().start();
+
+    // const_x0 and const_y0 are the constant parts of x0 and y0 during the row processing
+    float const_x0 = M01 * y_cur + M02;
+    float const_y0 = M11 * y_cur + M12;
+
+    // Affine warp coordinates
+    float x0 = start_x0 + const_x0;
+    float y0 = start_y0 + const_y0;
+
+    execute_window_loop(window, [&](const Coordinates & id)
+    {
+        // Check if we are processing a new row. If so, update the current row (y_cur), x0 and y0
+        if(y_cur != id.y())
+        {
+            y_cur = id.y();
+
+            const_x0 = M01 * y_cur + M02;
+            const_y0 = M11 * y_cur + M12;
+
+            x0 = start_x0 + const_x0;
+            y0 = start_y0 + const_y0;
+        }
+
+        // Only write to output if x0 and y0 are within the valid region.
+        // Otherwise the read value would be undefined.
+        if((min_y <= y0) && (y0 < max_y) && (min_x <= x0) && (x0 < max_x))
+        {
+            switch(interpolation)
+            {
+                case InterpolationPolicy::NEAREST_NEIGHBOR:
+                    *out.ptr() = nearest_interpolation(in.ptr(), x0, y0, stride);
+                    break;
+                case InterpolationPolicy::BILINEAR:
+                    *out.ptr() = pixel_bilinear_c1u8(in.ptr(), stride, x0, y0);
+                    break;
+                default:
+                    ARM_COMPUTE_ERROR("Interpolation not supported");
+            }
+        }
+
+        x0 += M00;
+        y0 += M10;
+    },
+    in, out);
+}
+
+template <InterpolationPolicy interpolation>
+void NEWarpAffineKernel<interpolation>::warp_constant(const Window &window)
+{
+    // Don't increment in X and Y direction for the input tensor
+    // A pointer to the start of this plane is needed as base for the precomputed offsets
+    Window win_in(window);
+    win_in.set(Window::DimX, Window::Dimension(0, 0, 0));
+    win_in.set(Window::DimY, Window::Dimension(0, 0, 0));
+
+    Iterator in(_input, win_in);
+    Iterator out(_output, window);
+
+    const int    min_x  = _input->info()->valid_region().anchor[0];
+    const int    max_x  = min_x + _input->info()->valid_region().shape[0];
+    const int    min_y  = _input->info()->valid_region().anchor[1];
+    const int    max_y  = min_y + _input->info()->valid_region().shape[1];
+    const size_t stride = _input->info()->strides_in_bytes()[1];
+
+    // x0 = M01 * x + M01 * y + M02
+    // y0 = M11 * x + M11 * y + M12
+    const float M00 = _matrix[0];
+    const float M10 = _matrix[1];
+    const float M01 = _matrix[0 + 1 * 2];
+    const float M11 = _matrix[1 + 1 * 2];
+    const float M02 = _matrix[0 + 2 * 2];
+    const float M12 = _matrix[1 + 2 * 2];
+
+    // "M00 * x" and "M10 * x", when x = window.x.start
+    const float start_x0 = M00 * window.x().start();
+    const float start_y0 = M10 * window.x().start();
+
+    // Current row
+    int y_cur = window.y().start();
+
+    // const_x0 and const_y0 are the constant parts of x0 and y0 during the row processing
+    float const_x0 = M01 * y_cur + M02;
+    float const_y0 = M11 * y_cur + M12;
+
+    // Affine warp coordinates
+    float x0 = start_x0 + const_x0;
+    float y0 = start_y0 + const_y0;
+
+    execute_window_loop(window, [&](const Coordinates & id)
+    {
+        // Check if we are processing a new row. If so, update the current row (y_cur), x0 and y0
+        if(y_cur != id.y())
+        {
+            y_cur = id.y();
+
+            const_x0 = M01 * y_cur + M02;
+            const_y0 = M11 * y_cur + M12;
+
+            x0 = start_x0 + const_x0;
+            y0 = start_y0 + const_y0;
+        }
+
+        // Only use input values if x0 and y0 are within the valid region.
+        // Otherwise write the constant border value.
+        if((min_y <= y0) && (y0 < max_y) && (min_x <= x0) && (x0 < max_x))
+        {
+            switch(interpolation)
+            {
+                case InterpolationPolicy::NEAREST_NEIGHBOR:
+                    *out.ptr() = nearest_interpolation(in.ptr(), x0, y0, stride);
+                    break;
+                case InterpolationPolicy::BILINEAR:
+                    *out.ptr() = pixel_bilinear_c1u8(in.ptr(), stride, x0, y0);
+                    break;
+                default:
+                    ARM_COMPUTE_ERROR("Interpolation not supported");
+            }
+        }
+        else
+        {
+            *out.ptr() = _constant_border_value;
+        }
+
+        x0 += M00;
+        y0 += M10;
+    },
+    in, out);
+}
+
+template <InterpolationPolicy interpolation>
+void NEWarpAffineKernel<interpolation>::warp_replicate(const Window &window)
+{
+    // Don't increment in X and Y direction for the input tensor
+    // A pointer to the start of this plane is needed as base for the precomputed offsets
+    Window win_in(window);
+    win_in.set(Window::DimX, Window::Dimension(0, 0, 0));
+    win_in.set(Window::DimY, Window::Dimension(0, 0, 0));
+
+    Iterator in(_input, win_in);
+    Iterator out(_output, window);
+
+    const int    min_x  = _input->info()->valid_region().anchor[0];
+    const int    max_x  = min_x + _input->info()->valid_region().shape[0];
+    const int    min_y  = _input->info()->valid_region().anchor[1];
+    const int    max_y  = min_y + _input->info()->valid_region().shape[1];
+    const size_t stride = _input->info()->strides_in_bytes()[1];
+
+    // Current row
+    int y_cur = window.y().start();
+
+    const float M00 = _matrix[0];
+    const float M10 = _matrix[1];
+    const float M01 = _matrix[0 + 1 * 2];
+    const float M11 = _matrix[1 + 1 * 2];
+    const float M02 = _matrix[0 + 2 * 2];
+    const float M12 = _matrix[1 + 2 * 2];
+
+    // "M00 * x" and "M10 * x", when x = window.x.start
+    const float start_x0 = M00 * window.x().start();
+    const float start_y0 = M10 * window.x().start();
+
+    // const_x0 and const_y0 are the constant parts of x0 and y0 during the row processing
+    float const_x0 = M01 * y_cur + M02;
+    float const_y0 = M11 * y_cur + M12;
+
+    float x0 = start_x0 + const_x0;
+    float y0 = start_y0 + const_y0;
+
+    execute_window_loop(window, [&](const Coordinates & id)
+    {
+        // Check if we are processing a new row. If so, update the current row (y_cur), x0 and y0
+        if(y_cur != id.y())
+        {
+            y_cur = id.y();
+
+            const_x0 = M01 * y_cur + M02;
+            const_y0 = M11 * y_cur + M12;
+
+            x0 = start_x0 + const_x0;
+            y0 = start_y0 + const_y0;
+        }
+
+        // Only load from (x0, y0) if the point is within the valid region.
+        // Otherwise load from the edge of the valid region.
+        if((min_y <= y0) && (y0 < max_y) && (min_x <= x0) && (x0 < max_x))
+        {
+            switch(interpolation)
+            {
+                case InterpolationPolicy::NEAREST_NEIGHBOR:
+                    *out.ptr() = nearest_interpolation(in.ptr(), x0, y0, stride);
+                    break;
+                case InterpolationPolicy::BILINEAR:
+                    *out.ptr() = pixel_bilinear_c1u8(in.ptr(), stride, x0, y0);
+                    break;
+                default:
+                    ARM_COMPUTE_ERROR("Interpolation not supported");
+            }
+        }
+        else
+        {
+            // Clamp coordinates
+            const auto xi = clamp<int>(x0, min_x, max_x - 1);
+            const auto yi = clamp<int>(y0, min_y, max_y - 1);
+
+            *out.ptr() = *(in.ptr() + xi + yi * stride);
+        }
+
+        x0 += M00;
+        y0 += M10;
+    },
+    in, out);
+}
+
+template <InterpolationPolicy interpolation>
+void NEWarpPerspectiveKernel<interpolation>::warp_undefined(const Window &window)
+{
+    // Don't increment in X and Y direction for the input tensor
+    // A pointer to the start of this plane is needed as base for the precomputed offsets
+    Window win_in(window);
+    win_in.set(Window::DimX, Window::Dimension(0, 0, 0));
+    win_in.set(Window::DimY, Window::Dimension(0, 0, 0));
+
+    Iterator in(_input, win_in);
+    Iterator out(_output, window);
+
+    const int    min_x  = _input->info()->valid_region().anchor[0];
+    const int    max_x  = min_x + _input->info()->valid_region().shape[0];
+    const int    min_y  = _input->info()->valid_region().anchor[1];
+    const int    max_y  = min_y + _input->info()->valid_region().shape[1];
+    const size_t stride = _input->info()->strides_in_bytes()[1];
+
+    // x0 = M00 * x + M01 * y + M02
+    // y0 = M10 * x + M11 * y + M12
+    // z0 = M20 * x + M21 * y + M22
+    // xn = x0 / z0
+    // yn = y0 / z0
+    const float M00 = _matrix[0];
+    const float M10 = _matrix[1];
+    const float M20 = _matrix[2];
+    const float M01 = _matrix[0 + 1 * 3];
+    const float M11 = _matrix[1 + 1 * 3];
+    const float M21 = _matrix[2 + 1 * 3];
+    const float M02 = _matrix[0 + 2 * 3];
+    const float M12 = _matrix[1 + 2 * 3];
+    const float M22 = _matrix[2 + 2 * 3];
+
+    // "M00 * x", "M10 * x" and "M20 * x", when x = window.x.start
+    const float start_x0 = M00 * window.x().start();
+    const float start_y0 = M10 * window.x().start();
+    const float start_z0 = M20 * window.x().start();
+
+    // Current row
+    int y_cur = window.y().start();
+
+    // const_x0, const_y0 and const_z0 are the constant parts of x0, y0 and z0 during the row processing
+    float const_x0 = M01 * y_cur + M02;
+    float const_y0 = M11 * y_cur + M12;
+    float const_z0 = M21 * y_cur + M22;
+
+    // Perspective warp coordinates
+    float x0 = start_x0 + const_x0;
+    float y0 = start_y0 + const_y0;
+    float z0 = start_z0 + const_z0;
+
+    execute_window_loop(window, [&](const Coordinates & id)
+    {
+        // Check if we are processing a new row. If so, update the current processed row (y_cur), x0, y0 and z0
+        if(y_cur != id.y())
+        {
+            y_cur = id.y();
+
+            const_x0 = M01 * y_cur + M02;
+            const_y0 = M11 * y_cur + M12;
+            const_z0 = M21 * y_cur + M22;
+
+            x0 = start_x0 + const_x0;
+            y0 = start_y0 + const_y0;
+            z0 = start_z0 + const_z0;
+        }
+
+        const float xn = x0 / z0;
+        const float yn = y0 / z0;
+
+        // Only write to output if xn and yn are within the valid region.
+        // Otherwise the read value would be undefined.
+        if((min_y <= yn) && (yn < max_y) && (min_x <= xn) && (xn < max_x))
+        {
+            switch(interpolation)
+            {
+                case InterpolationPolicy::NEAREST_NEIGHBOR:
+                    *out.ptr() = nearest_interpolation(in.ptr(), xn, yn, stride);
+                    break;
+                case InterpolationPolicy::BILINEAR:
+                    *out.ptr() = pixel_bilinear_c1u8(in.ptr(), stride, xn, yn);
+                    break;
+                default:
+                    ARM_COMPUTE_ERROR("Interpolation not supported");
+            }
+        }
+
+        x0 += M00;
+        y0 += M10;
+        z0 += M20;
+    },
+    in, out);
+}
+
+template <InterpolationPolicy interpolation>
+void NEWarpPerspectiveKernel<interpolation>::warp_constant(const Window &window)
+{
+    // Don't increment in X and Y direction for the input tensor
+    // A pointer to the start of this plane is needed as base for the precomputed offsets
+    Window win_in(window);
+    win_in.set(Window::DimX, Window::Dimension(0, 0, 0));
+    win_in.set(Window::DimY, Window::Dimension(0, 0, 0));
+
+    Iterator in(_input, win_in);
+    Iterator out(_output, window);
+
+    const int    min_x  = _input->info()->valid_region().anchor[0];
+    const int    max_x  = min_x + _input->info()->valid_region().shape[0];
+    const int    min_y  = _input->info()->valid_region().anchor[1];
+    const int    max_y  = min_y + _input->info()->valid_region().shape[1];
+    const size_t stride = _input->info()->strides_in_bytes()[1];
+
+    // x0 = M00 * x + M01 * y + M02
+    // y0 = M10 * x + M11 * y + M12
+    // z0 = M20 * x + M21 * y + M22
+    // xn = x0 / z0
+    // yn = y0 / z0
+    const float M00 = _matrix[0];
+    const float M10 = _matrix[1];
+    const float M20 = _matrix[2];
+    const float M01 = _matrix[0 + 1 * 3];
+    const float M11 = _matrix[1 + 1 * 3];
+    const float M21 = _matrix[2 + 1 * 3];
+    const float M02 = _matrix[0 + 2 * 3];
+    const float M12 = _matrix[1 + 2 * 3];
+    const float M22 = _matrix[2 + 2 * 3];
+
+    // "M00 * x", "M10 * x" and "M20 * x", when x = window.x.start
+    const float start_x0 = M00 * window.x().start();
+    const float start_y0 = M10 * window.x().start();
+    const float start_z0 = M20 * window.x().start();
+
+    // Current row
+    int y_cur = window.y().start();
+
+    // const_x0, const_y0 and const_z0 are the constant parts of x0, y0 and z0 during the row processing
+    float const_x0 = M01 * y_cur + M02;
+    float const_y0 = M11 * y_cur + M12;
+    float const_z0 = M21 * y_cur + M22;
+
+    // Perspective warp coordinates
+    float x0 = start_x0 + const_x0;
+    float y0 = start_y0 + const_y0;
+    float z0 = start_z0 + const_z0;
+
+    execute_window_loop(window, [&](const Coordinates & id)
+    {
+        // Check if we are processing a new row. If so, update the current row (y_cur), x0, y0 and z0
+        if(y_cur != id.y())
+        {
+            y_cur = id.y();
+
+            const_x0 = M01 * y_cur + M02;
+            const_y0 = M11 * y_cur + M12;
+            const_z0 = M21 * y_cur + M22;
+
+            x0 = start_x0 + const_x0;
+            y0 = start_y0 + const_y0;
+            z0 = start_z0 + const_z0;
+        }
+
+        const float xn = x0 / z0;
+        const float yn = y0 / z0;
+
+        // Only use input values if xn and yn are within the valid region.
+        // Otherwise write the constant border value.
+        if((min_y <= yn) && (yn < max_y) && (min_x <= xn) && (xn < max_x))
+        {
+            switch(interpolation)
+            {
+                case InterpolationPolicy::NEAREST_NEIGHBOR:
+                    *out.ptr() = nearest_interpolation(in.ptr(), xn, yn, stride);
+                    break;
+                case InterpolationPolicy::BILINEAR:
+                    *out.ptr() = pixel_bilinear_c1u8(in.ptr(), stride, xn, yn);
+                    break;
+                default:
+                    ARM_COMPUTE_ERROR("Interpolation not supported");
+            }
+        }
+        else
+        {
+            *out.ptr() = _constant_border_value;
+        }
+
+        x0 += M00;
+        y0 += M10;
+        z0 += M20;
+    },
+    in, out);
+}
+
+template <InterpolationPolicy interpolation>
+void NEWarpPerspectiveKernel<interpolation>::warp_replicate(const Window &window)
+{
+    // Don't increment in X and Y direction for the input tensor
+    // A pointer to the start of this plane is needed as base for the precomputed offsets
+    Window win_in(window);
+    win_in.set(Window::DimX, Window::Dimension(0, 0, 0));
+    win_in.set(Window::DimY, Window::Dimension(0, 0, 0));
+
+    Iterator in(_input, win_in);
+    Iterator out(_output, window);
+
+    const int    min_x  = _input->info()->valid_region().anchor[0];
+    const int    max_x  = min_x + _input->info()->valid_region().shape[0];
+    const int    min_y  = _input->info()->valid_region().anchor[1];
+    const int    max_y  = min_y + _input->info()->valid_region().shape[1];
+    const size_t stride = _input->info()->strides_in_bytes()[1];
+
+    // Current row
+    int y_cur = window.y().start();
+
+    // x0 = M00 * x + M01 * y + M02
+    // y0 = M10 * x + M11 * y + M12
+    // z0 = M20 * x + M21 * y + M22
+    // xn = x0 / z0
+    // yn = y0 / z0
+    const float M00 = _matrix[0];
+    const float M10 = _matrix[1];
+    const float M20 = _matrix[2];
+    const float M01 = _matrix[0 + 1 * 3];
+    const float M11 = _matrix[1 + 1 * 3];
+    const float M21 = _matrix[2 + 1 * 3];
+    const float M02 = _matrix[0 + 2 * 3];
+    const float M12 = _matrix[1 + 2 * 3];
+    const float M22 = _matrix[2 + 2 * 3];
+
+    // "M00 * x", "M10 * x" and "M20 * x", when x = window.x.start
+    const float start_x0 = M00 * window.x().start();
+    const float start_y0 = M10 * window.x().start();
+    const float start_z0 = M20 * window.x().start();
+
+    // const_x0, const_y0 and const_z0 are the constant parts of x0, y0 and z0 during the row processing
+    float const_x0 = M01 * y_cur + M02;
+    float const_y0 = M11 * y_cur + M12;
+    float const_z0 = M21 * y_cur + M22;
+
+    // Perspective warp coordinates
+    float x0 = start_x0 + const_x0;
+    float y0 = start_y0 + const_y0;
+    float z0 = start_z0 + const_z0;
+
+    execute_window_loop(window, [&](const Coordinates & id)
+    {
+        // Check if we are processing a new row. If so, update the current row (y_cur), x0, y0 and z0
+        if(y_cur != id.y())
+        {
+            y_cur = id.y();
+
+            const_x0 = M01 * y_cur + M02;
+            const_y0 = M11 * y_cur + M12;
+            const_z0 = M21 * y_cur + M22;
+
+            x0 = start_x0 + const_x0;
+            y0 = start_y0 + const_y0;
+            z0 = start_z0 + const_z0;
+        }
+
+        const float xn = x0 / z0;
+        const float yn = y0 / z0;
+
+        // Only load from (x0, y0) if the point is within the valid region.
+        // Otherwise load from the edge of the valid region.
+        if((min_y <= yn) && (yn < max_y) && (min_x <= xn) && (xn < max_x))
+        {
+            switch(interpolation)
+            {
+                case InterpolationPolicy::NEAREST_NEIGHBOR:
+                    *out.ptr() = nearest_interpolation(in.ptr(), xn, yn, stride);
+                    break;
+                case InterpolationPolicy::BILINEAR:
+                    *out.ptr() = pixel_bilinear_c1u8(in.ptr(), stride, xn, yn);
+                    break;
+                default:
+                    ARM_COMPUTE_ERROR("Interpolation not supported");
+            }
+        }
+        else
+        {
+            // Clamp coordinates
+            const auto xi = clamp<int>(x0, min_x, max_x - 1);
+            const auto yi = clamp<int>(y0, min_y, max_y - 1);
+
+            *out.ptr() = *(in.ptr() + xi + yi * stride);
+        }
+
+        x0 += M00;
+        y0 += M10;
+        z0 += M20;
+    },
+    in, out);
+}
+
+template class arm_compute::NEWarpAffineKernel<InterpolationPolicy::NEAREST_NEIGHBOR>;
+template class arm_compute::NEWarpAffineKernel<InterpolationPolicy::BILINEAR>;
+template class arm_compute::NEWarpPerspectiveKernel<InterpolationPolicy::NEAREST_NEIGHBOR>;
+template class arm_compute::NEWarpPerspectiveKernel<InterpolationPolicy::BILINEAR>;