Fix Chinese font rendering in Streamlit charts

app.py

@@ -10,7 +10,9 @@ import json
 from pathlib import Path
 from typing import Dict, List, Sequence, Tuple
 
+import matplotlib as mpl
 import matplotlib.pyplot as plt
+from matplotlib import font_manager
 import numpy as np
 import streamlit as st
 
@@ -73,6 +75,46 @@ CUSTOM_CSS = """
 """
 
 
+def configure_matplotlib_cjk_font() -> None:
+    """配置 Matplotlib 中文字体。
+
+    Streamlit 自身用浏览器字体渲染中文，通常没有问题；Matplotlib 图像会走
+    后端字体管理，如果默认 DejaVu Sans 不含中文字形，就会显示成方块。
+    """
+
+    candidate_paths = [
+        "/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc",
+        "/usr/share/fonts/opentype/noto/NotoSansCJK-Bold.ttc",
+        "/usr/share/fonts/truetype/droid/DroidSansFallbackFull.ttf",
+    ]
+    candidate_names = [
+        "Noto Sans CJK SC",
+        "Noto Sans CJK JP",
+        "Droid Sans Fallback",
+        "WenQuanYi Micro Hei",
+        "Source Han Sans SC",
+        "SimHei",
+    ]
+
+    discovered_names: List[str] = []
+    for path_str in candidate_paths:
+        path = Path(path_str)
+        if not path.exists():
+            continue
+        try:
+            font_manager.fontManager.addfont(str(path))
+            discovered_names.append(font_manager.FontProperties(fname=str(path)).get_name())
+        except Exception:
+            continue
+
+    mpl.rcParams["font.family"] = "sans-serif"
+    mpl.rcParams["font.sans-serif"] = [*discovered_names, *candidate_names, "DejaVu Sans"]
+    mpl.rcParams["axes.unicode_minus"] = False
+
+
+configure_matplotlib_cjk_font()
+
+
 def _require_nibabel():
     try:
         import nibabel as nib  # type: ignore
@@ -199,7 +241,7 @@ def render_image(image: np.ndarray, caption: str, cmap: str = "gray") -> None:
     ax.imshow(orient_for_display(image), cmap=cmap, interpolation="nearest")
     ax.set_title(caption, fontsize=10)
     ax.axis("off")
-    st.pyplot(fig, use_container_width=True)
+    st.pyplot(fig, width="stretch")
     plt.close(fig)
 
 
@@ -208,7 +250,7 @@ def render_rgb(image: np.ndarray, caption: str) -> None:
     ax.imshow(orient_for_display(image), interpolation="nearest")
     ax.set_title(caption, fontsize=10)
     ax.axis("off")
-    st.pyplot(fig, use_container_width=True)
+    st.pyplot(fig, width="stretch")
     plt.close(fig)
 
 
@@ -220,7 +262,7 @@ def render_heatmap_overlay(base_slice: np.ndarray, mag_slice: np.ndarray, alpha:
     ax.set_title(caption, fontsize=10)
     ax.axis("off")
     fig.colorbar(im, ax=ax, fraction=0.046, pad=0.02)
-    st.pyplot(fig, use_container_width=True)
+    st.pyplot(fig, width="stretch")
     plt.close(fig)
 
 
@@ -321,7 +363,7 @@ def render_metric_charts(fixed_xyz: np.ndarray, moving_xyz: np.ndarray, warped_x
     axes[1].set_xlabel("Slice")
     axes[1].grid(alpha=0.22)
     axes[1].legend(frameon=False)
-    st.pyplot(fig, use_container_width=True)
+    st.pyplot(fig, width="stretch")
     plt.close(fig)
 
     if ddf_xyz is not None:
@@ -332,7 +374,7 @@ def render_metric_charts(fixed_xyz: np.ndarray, moving_xyz: np.ndarray, warped_x
         ax.set_xlabel("mm")
         ax.set_ylabel("Voxel count")
         ax.grid(axis="y", alpha=0.2)
-        st.pyplot(fig2, use_container_width=True)
+        st.pyplot(fig2, width="stretch")
         plt.close(fig2)
 
 
@@ -370,7 +412,7 @@ def main() -> None:
         out_dir = st.text_input("输出目录", value=str(INFERENCE_DIR))
         display_max_voxels = st.slider("Web显示体素上限", 2_000_000, 30_000_000, 14_000_000, 1_000_000)
 
-        start = st.button("开始推理", type="primary", use_container_width=True)
+        start = st.button("开始推理", type="primary", width="stretch")
         if start:
             with st.spinner("推理运行中"):
                 try: