diff --git a/bun.lockb b/bun.lockb
index 4dcb909..0741acf 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/package.json b/package.json
index 15e026f..46e0cf4 100644
--- a/package.json
+++ b/package.json
@@ -17,6 +17,7 @@
     "tsx": "^4.20.5"
   },
   "dependencies": {
-    "pdf-lib": "^1.17.1"
+    "pdf-lib": "^1.17.1",
+    "pptxgenjs": "^4.0.1"
   }
 }
diff --git a/skills/baoyu-slide-deck/scripts/merge-to-pdf.ts b/skills/baoyu-slide-deck/scripts/merge-to-pdf.ts
index 6ba342c..5edccdc 100644
--- a/skills/baoyu-slide-deck/scripts/merge-to-pdf.ts
+++ b/skills/baoyu-slide-deck/scripts/merge-to-pdf.ts
@@ -73,8 +73,8 @@ async function createPdf(slides: SlideInfo[], outputPath: string) {
 
   for (const slide of slides) {
     const imageData = readFileSync(slide.path);
-    const ext = slide.filename.toLowerCase();
-    const image = ext.endsWith(".png")
+    const isPng = imageData[0] === 0x89 && imageData[1] === 0x50 && imageData[2] === 0x4e && imageData[3] === 0x47;
+    const image = isPng
       ? await pdfDoc.embedPng(imageData)
       : await pdfDoc.embedJpg(imageData);