| | |
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| | | // Focal loss |
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| | | if (focal_loss) { |
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| | | // Focal Loss for Dense Object Detection: http://blog.csdn.net/linmingan/article/details/77885832 |
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| | | //printf("Used Focal-loss \n"); |
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| | | float alpha = 0.5; // 0.25 |
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| | | float gamma = 2.0; |
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| | | float alpha = 0.5; // 0.25 or 0.5 |
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| | | //float gamma = 2; // hardcoded in many places of the grad-formula |
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| | | |
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| | | int ti = index + class_id; |
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| | | float grad = -gamma * (1 - output[ti])*logf(fmaxf(output[ti], 0.0000001))*output[ti] + (1 - output[ti])*(1 - output[ti]); |
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| | | float grad = -2 * (1 - output[ti])*logf(fmaxf(output[ti], 0.0000001))*output[ti] + (1 - output[ti])*(1 - output[ti]); |
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| | | |
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| | | for (n = 0; n < classes; ++n) { |
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| | | delta[index + n] = scale * (((n == class_id) ? 1 : 0) - output[index + n]); |
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