Function rgb_to_luminance

tests/AssetsLibrary.cpp:55–70

{
template <typename T, typename std::enable_if<std::is_integral<T>::value, int>::type = 0>
void rgb_to_luminance(const RawTensor &src, RawTensor &dst)
{
    // Ensure in/out tensors have same image dimensions (independent of element size and number of channels)
    ARM_COMPUTE_ERROR_ON_MSG(src.num_elements() != dst.num_elements(),
                             "Input and output images must have equal dimensions");

    const size_t num_elements = dst.num_elements();

    // Currently, input is always RGB888 (3 U8 channels per element). Output can be U8, U16/S16 or U32
    // Note that src.data()[i] returns pointer to first channel of element[i], so RGB values have [0,1,2] offsets
    for (size_t i = 0, j = 0; j < num_elements; i += 3, ++j)
    {
        reinterpret_cast<T *>(dst.data())[j] =
            0.2126f * src.data()[i] + 0.7152f * src.data()[i + 1] + 0.0722f * src.data()[i + 2];
    }
}

void extract_r_from_rgb(const RawTensor &src, RawTensor &dst)
{