doc: add ControlNet example

Signed-off-by: Xin Liu <[email protected]>

examples/control_net.md

@@ -0,0 +1,93 @@
+# ControlNet
+
+This example demonstrates how to use the `sd-api-server` to generate images using the stable diffusion model with the openpose control model.
+
+## Setup
+
+- Install WasmEdge v0.14.1
+
+  ```bash
+  curl -sSf https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install_v2.sh | bash -s -- -v 0.14.1
+  ```
+
+  If the installation is successful, WasmEdge will be installed in `$HOME/.wasmedge`.
+
+- Deploy `wasmedge_stablediffusion` plugin
+
+  > [!NOTE]
+  > For the purpose of demonstration, we will use the stable diffusion plugin for Mac Apple Silicon. You can find the plugin for other platforms [Releases/0.14.1](https://github.com/WasmEdge/WasmEdge/releases/tag/0.14.1)
+
+  ```bash
+  # Download stable diffusion plugin for Mac Apple Silicon
+  curl -LO https://github.com/WasmEdge/WasmEdge/releases/download/0.14.1/WasmEdge-plugin-wasmedge_stablediffusion-metal-0.14.1-darwin_arm64.tar.gz
+
+  # Unzip the plugin to $HOME/.wasmedge/plugin
+  tar -xzf WasmEdge-plugin-wasmedge_stablediffusion-metal-0.14.1-darwin_arm64.tar.gz -C $HOME/.wasmedge/plugin
+
+  rm $HOME/.wasmedge/plugin/libwasmedgePluginWasiNN.dylib
+  ```
+
+## Run sd-api-server
+
+- Download stable-diffusion model
+
+  ```bash
+  curl -LO https://huggingface.co/second-state/stable-diffusion-v-1-4-GGUF/resolve/main/stable-diffusion-v1-4-Q4_0.gguf
+  ```
+
+- Download openpose control model
+
+  ```bash
+  curl -LO https://huggingface.co/webui/ControlNet-modules-safetensors/resolve/main/control_openpose-fp16.safetensors
+  ```
+
+- Run sd-api-server
+
+  ```bash
+  wasmedge --dir .:. \
+    sd-api-server.wasm \
+    --model-name sd-v1.4 \
+    --model stable-diffusion-v1-4-Q8_0.gguf \
+    --control-net control_openpose-fp16.safetensors \
+    --task text2image
+  ```
+
+## Usage
+
+- Download the control image
+
+  ```bash
+  curl -LO https://huggingface.co/webui/ControlNet-modules-safetensors/resolve/main/control_2.png
+  ```
+
+- Send a POST request to the server to generate an image
+
+  ```bash
+  curl --location 'http://localhost:10086/v1/images/generations' \
+  --form 'control_image=@"control_2.png"' \
+  --form 'prompt="1girl, high quality, masterpiece, anime style, white dress, sun hat"' \
+  --form 'cfg_scale="7"' \
+  --form 'sample_method="euler_a"' \
+  --form 'steps="20"' \
+  --form 'seed="-1"'
+  ```
+
+  If the request is handled successfully, the server will respond with a JSON object containing the URL of the generated image.
+
+  ```json
+  {
+    "created": 1728910462,
+    "data": [
+        {
+            "url": "/archives/file_cb247eeb-2507-4a95-9a78-2f4c02a6300e/output.png",
+            "prompt": "1girl, high quality, masterpiece, anime style, white dress, sun hat"
+        }
+    ]
+  }
+  ```
+
+  The generated image looks like this:
+
+  <div align=center>
+  <img src="../image/girl_controlnet.png" alt="1girl, high quality, masterpiece, anime style, white dress, sun hat" width="60%" />
+  </div>