| 53 | } |
| 54 | |
| 55 | std::vector<float> ResizeBilinearAndNormalize(const InferenceTestImage & image, |
| 56 | const unsigned int outputWidth, |
| 57 | const unsigned int outputHeight, |
| 58 | const float scale, |
| 59 | const std::array<float, 3>& mean, |
| 60 | const std::array<float, 3>& stddev) |
| 61 | { |
| 62 | std::vector<float> out; |
| 63 | out.resize(outputWidth * outputHeight * 3); |
| 64 | |
| 65 | // We follow the definition of TensorFlow and AndroidNN: the top-left corner of a texel in the output |
| 66 | // image is projected into the input image to figure out the interpolants and weights. Note that this |
| 67 | // will yield different results than if projecting the centre of output texels. |
| 68 | |
| 69 | const unsigned int inputWidth = image.GetWidth(); |
| 70 | const unsigned int inputHeight = image.GetHeight(); |
| 71 | |
| 72 | // How much to scale pixel coordinates in the output image to get the corresponding pixel coordinates |
| 73 | // in the input image. |
| 74 | const float scaleY = armnn::numeric_cast<float>(inputHeight) / armnn::numeric_cast<float>(outputHeight); |
| 75 | const float scaleX = armnn::numeric_cast<float>(inputWidth) / armnn::numeric_cast<float>(outputWidth); |
| 76 | |
| 77 | uint8_t rgb_x0y0[3]; |
| 78 | uint8_t rgb_x1y0[3]; |
| 79 | uint8_t rgb_x0y1[3]; |
| 80 | uint8_t rgb_x1y1[3]; |
| 81 | |
| 82 | for (unsigned int y = 0; y < outputHeight; ++y) |
| 83 | { |
| 84 | // Corresponding real-valued height coordinate in input image. |
| 85 | const float iy = armnn::numeric_cast<float>(y) * scaleY; |
| 86 | |
| 87 | // Discrete height coordinate of top-left texel (in the 2x2 texel area used for interpolation). |
| 88 | const float fiy = floorf(iy); |
| 89 | const unsigned int y0 = armnn::numeric_cast<unsigned int>(fiy); |
| 90 | |
| 91 | // Interpolation weight (range [0,1]) |
| 92 | const float yw = iy - fiy; |
| 93 | |
| 94 | for (unsigned int x = 0; x < outputWidth; ++x) |
| 95 | { |
| 96 | // Real-valued and discrete width coordinates in input image. |
| 97 | const float ix = armnn::numeric_cast<float>(x) * scaleX; |
| 98 | const float fix = floorf(ix); |
| 99 | const unsigned int x0 = armnn::numeric_cast<unsigned int>(fix); |
| 100 | |
| 101 | // Interpolation weight (range [0,1]). |
| 102 | const float xw = ix - fix; |
| 103 | |
| 104 | // Discrete width/height coordinates of texels below and to the right of (x0, y0). |
| 105 | const unsigned int x1 = std::min(x0 + 1, inputWidth - 1u); |
| 106 | const unsigned int y1 = std::min(y0 + 1, inputHeight - 1u); |
| 107 | |
| 108 | std::tie(rgb_x0y0[0], rgb_x0y0[1], rgb_x0y0[2]) = image.GetPixelAs3Channels(x0, y0); |
| 109 | std::tie(rgb_x1y0[0], rgb_x1y0[1], rgb_x1y0[2]) = image.GetPixelAs3Channels(x1, y0); |
| 110 | std::tie(rgb_x0y1[0], rgb_x0y1[1], rgb_x0y1[2]) = image.GetPixelAs3Channels(x0, y1); |
| 111 | std::tie(rgb_x1y1[0], rgb_x1y1[1], rgb_x1y1[2]) = image.GetPixelAs3Channels(x1, y1); |
| 112 | |