# Ultralytics 🚀 AGPL-3.0 License - https://ultralytics.com/license

# Ultralytics YOLO11 object detection model with P3/8 - P5/32 outputs
# Model docs: https://docs.ultralytics.com/models/yolo11
# Task docs: https://docs.ultralytics.com/tasks/detect

# Parameters
nc: 4 # number of classes
scales: # model compound scaling constants, i.e. 'model=yolo11n.yaml' will call yolo11.yaml with scale 'n'
  # [depth, width, max_channels]
  n: [0.50, 0.25, 1024] # summary: 181 layers, 2624080 parameters, 2624064 gradients, 6.6 GFLOPs
#  s: [0.50, 0.50, 1024] # summary: 181 layers, 9458752 parameters, 9458736 gradients, 21.7 GFLOPs
#  m: [0.50, 1.00, 512] # summary: 231 layers, 20114688 parameters, 20114672 gradients, 68.5 GFLOPs
#  l: [1.00, 1.00, 512] # summary: 357 layers, 25372160 parameters, 25372144 gradients, 87.6 GFLOPs
#  x: [1.00, 1.50, 512] # summary: 357 layers, 56966176 parameters, 56966160 gradients, 196.0 GFLOPs

# YOLO11n backbone
backbone:
  # [from, repeats, module, args]
  - [-1, 1, Conv, [64, 3, 2]] # 0-P1/2
  - [-1, 1, Conv, [128, 3, 2]] # 1-P2/4
  - [-1, 2, C3k2, [256, False, 0.25]]
  - [-1, 1, Conv, [256, 3, 2]] # 3-P3/8
  - [-1, 2, C3k2, [512, False, 0.25]]
  - [-1, 1, Conv, [512, 3, 2]] # 5-P4/16
  - [-1, 2, C3k2, [512, True]]
  - [-1, 1, Conv, [1024, 3, 2]] # 7-P5/32
  - [-1, 2, C3k2, [1024, True]]
  - [-1, 1, SPPF, [1024, 5]] # 9
  - [-1, 2, C2PSA, [1024]] # 10

# YOLO11n head
#head:
#  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
#  - [[-1, 6], 1, Concat, [1]] # cat backbone P4
#  - [-1, 2, C3k2, [512, False]] # 13
#
#  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
#  - [[-1, 4], 1, Concat, [1]] # cat backbone P3
#  - [-1, 2, C3k2, [256, False]] # 16 (P3/8-small)
#
#  - [-1, 1, Conv, [256, 3, 2]]
#  - [[-1, 13], 1, Concat, [1]] # cat head P4
#  - [-1, 2, C3k2, [512, False]] # 19 (P4/16-medium)
#
#  - [-1, 1, Conv, [512, 3, 2]]
#  - [[-1, 10], 1, Concat, [1]] # cat head P5
#  - [-1, 2, C3k2, [1024, True]] # 22 (P5/32-large)
#
#  - [[16, 19, 22], 1, Detect, [nc]] # Detect(P3, P4, P5)

# YOLO11-P2 head
head:
  # ---------------- P5 -> P4 ----------------
  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 6], 1, Concat, [1]]        # cat backbone P4
  - [-1, 2, C3k2, [512, False]]      # P4

  # ---------------- P4 -> P3 ----------------
  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 4], 1, Concat, [1]]        # cat backbone P3
  - [-1, 2, C3k2, [256, False]]      # P3

  # ---------------- P3 -> P2 (新增) ----------------
  - [-1, 1, nn.Upsample, [None, 2, "nearest"]]
  - [[-1, 1], 1, Concat, [1]]        # cat backbone P2
  - [-1, 2, C3k2, [128, False]]      # P2 (x-small)

  # ---------------- P2 -> P3 ----------------
  - [-1, 1, Conv, [128, 3, 2]]
  - [[-1, 16], 1, Concat, [1]]       # cat head P3
  - [-1, 2, C3k2, [256, False]]      # P3

  # ---------------- P3 -> P4 ----------------
  - [-1, 1, Conv, [256, 3, 2]]
  - [[-1, 13], 1, Concat, [1]]       # cat head P4
  - [-1, 2, C3k2, [512, False]]      # P4

  # ---------------- P4 -> P5 ----------------
  - [-1, 1, Conv, [512, 3, 2]]
  - [[-1, 10], 1, Concat, [1]]       # cat head P5
  - [-1, 2, C3k2, [1024, True]]      # P5

  # ---------------- Detect ----------------
  - [[19, 22, 25, 28], 1, Detect, [nc]]  # Detect(P2, P3, P4, P5)