diff --git a/components/image-preview.tsx b/components/image-preview.tsx
index 45275de..da33459 100644
--- a/components/image-preview.tsx
+++ b/components/image-preview.tsx
@@ -78,26 +78,38 @@ export function ImagePreview({
     let is4K = false;
     let parsed = false;
 
+    const applySizeInfo = (rawSize?: string) => {
+      if (!rawSize) return;
+      const normalized = rawSize.trim().toLowerCase();
+
+      if (normalized === "4k") {
+        is4K = true;
+        maxWidth = 500;
+        return;
+      }
+      if (normalized === "2k") {
+        is4K = false;
+        maxWidth = 400;
+        return;
+      }
+      if (normalized === "1k") {
+        is4K = false;
+        maxWidth = 300;
+        return;
+      }
+
+      // 仅纯数字时才按像素宽度解析，避免 "2k" 被 parseInt 误解析成 2
+      if (/^\d+$/.test(normalized)) {
+        maxWidth = parseInt(normalized, 10);
+      }
+    };
+
     // 最新格式：使用 ||| 分隔 (不会与 LaTeX 数学公式或 Markdown 表格冲突)
     if (alt && alt.includes("thumb|||")) {
       const content = alt.substring(alt.indexOf("thumb|||") + 8);
       const parts = content.split("|||");
       originalUrl = parts[0];
-      const extraInfo = parts[1];
-      
-      if (extraInfo === "4K") {
-        is4K = true;
-        maxWidth = 500; // 4K 图片显示 500px 宽
-      } else if (extraInfo === "2K") {
-        // 2K 是高质量图片，显示较大尺寸
-        is4K = false;
-        maxWidth = 400; // 2K 图片显示 400px 宽
-      } else if (extraInfo === "1K") {
-        is4K = false;
-        maxWidth = 300; // 1K 图片显示 300px 宽
-      } else if (extraInfo && !isNaN(parseInt(extraInfo, 10))) {
-        maxWidth = parseInt(extraInfo, 10);
-      }
+      applySizeInfo(parts[1]);
       parsed = true;
       console.log("[ImagePreview] Parsed with ||| format:", { originalUrl: originalUrl?.substring(0, 80), is4K });
     }
@@ -106,20 +118,7 @@ export function ImagePreview({
       const content = alt.substring(alt.indexOf("thumb$$") + 7);
       const parts = content.split("$$");
       originalUrl = parts[0];
-      const extraInfo = parts[1];
-      
-      if (extraInfo === "4K") {
-        is4K = true;
-        maxWidth = 500;
-      } else if (extraInfo === "2K") {
-        is4K = false;
-        maxWidth = 400;
-      } else if (extraInfo === "1K") {
-        is4K = false;
-        maxWidth = 300;
-      } else if (extraInfo && !isNaN(parseInt(extraInfo, 10))) {
-        maxWidth = parseInt(extraInfo, 10);
-      }
+      applySizeInfo(parts[1]);
       parsed = true;
       console.log("[ImagePreview] Parsed with $$ format:", { originalUrl: originalUrl?.substring(0, 80), is4K });
     }
@@ -128,20 +127,7 @@ export function ImagePreview({
       const content = alt.substring(alt.indexOf("thumb|") + 6);
       const parts = content.split("|");
       originalUrl = parts[0];
-      const extraInfo = parts[1];
-      
-      if (extraInfo === "4K") {
-        is4K = true;
-        maxWidth = 500;
-      } else if (extraInfo === "2K") {
-        is4K = false;
-        maxWidth = 400;
-      } else if (extraInfo === "1K") {
-        is4K = false;
-        maxWidth = 300;
-      } else if (extraInfo && !isNaN(parseInt(extraInfo, 10))) {
-        maxWidth = parseInt(extraInfo, 10);
-      }
+      applySizeInfo(parts[1]);
       parsed = true;
       console.log("[ImagePreview] Parsed with | format:", { originalUrl: originalUrl?.substring(0, 80), is4K });
     }