From 81290b07376c5abb4988a492dda70913bb90133d Mon Sep 17 00:00:00 2001
From: AlexeyAB <alexeyab84@gmail.com>
Date: Mon, 2 Mar 2020 17:36:08 +0300
Subject: [PATCH] Fixed label_smoothing for Detector

---
 src/gaussian_yolo_layer.c | 16 ++++++++++++++--
 src/yolo_layer.c          | 16 ++++++++++++++--
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/gaussian_yolo_layer.c b/src/gaussian_yolo_layer.c
index 7e9efb21..101005ee 100644
--- a/src/gaussian_yolo_layer.c
+++ b/src/gaussian_yolo_layer.c
@@ -371,13 +371,25 @@ void delta_gaussian_yolo_class(float *output, float *delta, int index, int class
 {
     int n;
     if (delta[index]){
-        delta[index + stride*class_id] = (1 - label_smooth_eps) - output[index + stride*class_id];
+        if (label_smooth_eps > 0) {
+            float out_val = output[index + stride*class_id] * (1 - label_smooth_eps) + 0.5*label_smooth_eps;
+            delta[index + stride*class_id] = 1 - out_val;
+        }
+        else {
+            delta[index + stride*class_id] = 1 - output[index + stride*class_id];
+        }
         if (classes_multipliers) delta[index + stride*class_id] *= classes_multipliers[class_id];
         if(avg_cat) *avg_cat += output[index + stride*class_id];
         return;
     }
     for(n = 0; n < classes; ++n){
-        delta[index + stride*n] = ((n == class_id) ? (1 - label_smooth_eps) : (0 + label_smooth_eps/classes)) - output[index + stride*n];
+        if (label_smooth_eps > 0) {
+            float out_val = output[index + stride*class_id] * (1 - label_smooth_eps) + 0.5*label_smooth_eps;
+            delta[index + stride*n] = ((n == class_id) ? 1 : 0) - out_val;
+        }
+        else {
+            delta[index + stride*n] = ((n == class_id) ? 1 : 0) - output[index + stride*n];
+        }
         if (classes_multipliers && n == class_id) delta[index + stride*class_id] *= classes_multipliers[class_id];
         if(n == class_id && avg_cat) *avg_cat += output[index + stride*n];
     }
diff --git a/src/yolo_layer.c b/src/yolo_layer.c
index 86a78895..d80dcc1d 100644
--- a/src/yolo_layer.c
+++ b/src/yolo_layer.c
@@ -257,7 +257,13 @@ void delta_yolo_class(float *output, float *delta, int index, int class_id, int
 {
     int n;
     if (delta[index + stride*class_id]){
-        delta[index + stride*class_id] = (1 - label_smooth_eps) - output[index + stride*class_id];
+        if (label_smooth_eps > 0) {
+            float out_val = output[index + stride*class_id] * (1 - label_smooth_eps) + 0.5*label_smooth_eps;
+            delta[index + stride*class_id] = 1 - out_val;
+        }
+        else {
+            delta[index + stride*class_id] = 1 - output[index + stride*class_id];
+        }
         if (classes_multipliers) delta[index + stride*class_id] *= classes_multipliers[class_id];
         if(avg_cat) *avg_cat += output[index + stride*class_id];
         return;
@@ -285,7 +291,13 @@ void delta_yolo_class(float *output, float *delta, int index, int class_id, int
     else {
         // default
         for (n = 0; n < classes; ++n) {
-            delta[index + stride*n] = ((n == class_id) ? (1 - label_smooth_eps) : (0 + label_smooth_eps/classes)) - output[index + stride*n];
+            if (label_smooth_eps > 0) {
+                float out_val = output[index + stride*class_id] * (1 - label_smooth_eps) + 0.5*label_smooth_eps;
+                delta[index + stride*n] = ((n == class_id) ? 1 : 0) - out_val;
+            }
+            else {
+                delta[index + stride*n] = ((n == class_id) ? 1 : 0) - output[index + stride*n];
+            }
             if (classes_multipliers && n == class_id) delta[index + stride*class_id] *= classes_multipliers[class_id];
             if (n == class_id && avg_cat) *avg_cat += output[index + stride*n];
         }