U-Net Architecture

digraph unet {
  rankdir=LR;
  graph [bgcolor=transparent];
  node [shape=box, style="rounded,filled", fontname=Inter, fontsize=10];

  In [label="Input\n(H × W × 3)", fillcolor="#dbeafe"];
  E1 [label="Conv ×2\n64ch", fillcolor="#dbeafe"];
  E2 [label="Conv ×2\n128ch", fillcolor="#dbeafe"];
  E3 [label="Conv ×2\n256ch", fillcolor="#dbeafe"];
  Bot [label="Bottleneck\n512ch", fillcolor="#fef3c7"];
  D3 [label="Up + Conv\n256ch", fillcolor="#dcfce7"];
  D2 [label="Up + Conv\n128ch", fillcolor="#dcfce7"];
  D1 [label="Up + Conv\n64ch", fillcolor="#dcfce7"];
  Out [label="Output\n(H × W × C)", fillcolor="#fce7f3"];

  In -> E1 -> E2 -> E3 -> Bot -> D3 -> D2 -> D1 -> Out;
  E1 -> D1 [style=dashed, label="skip"];
  E2 -> D2 [style=dashed, label="skip"];
  E3 -> D3 [style=dashed, label="skip"];
}