diff --git a/dlibrary/dlibrary.py b/dlibrary/dlibrary.py
index a862737..82cf74f 100755
--- a/dlibrary/dlibrary.py
+++ b/dlibrary/dlibrary.py
@@ -441,10 +441,18 @@ def is_single_image(page):
     blocks = page.get_text('blocks')
     return len(blocks) == 1 and blocks[0][6] == 1
 
+def extract_image(pdf, xref):
+    image = pdf.extract_image(xref)
+    if f'.{image["ext"]}' in IMAGE_FILE_EXTENSIONS:
+        return image
+    print(f'Converting image from {image["ext"]} to png')
+    pix = fitz.Pixmap(pdf, xref)
+    return { 'ext': 'png', 'image': pix.tobytes('png') }
+
 def pdf_images(pdf, force=False):
     images_by_page = [(page.get_images(), is_single_image(page)) for page in pdf]
     if all(len(images) == 1 and single for (images, single) in images_by_page):
-        return (pdf.extract_image(images[0][0]) for (images, _) in images_by_page)
+        return (extract_image(pdf, images[0][0]) for (images, _) in images_by_page)
 
     print("Checking PDF images the quick way failed, trying the slow way")
     def xref_or_image_generator():
@@ -456,7 +464,7 @@ def pdf_images(pdf, force=False):
                 if xref_mode:
                     yield xref
                 else:
-                    yield pdf.extract_image(xref)
+                    yield extract_image(pdf, xref)
             else:
                 if xref_mode:
                     raise ValueError
@@ -476,7 +484,7 @@ def pdf_images(pdf, force=False):
         print('\nFailed')
         return None
     print('Success')
-    return (pdf.extract_image(xref) for xref in xrefs)
+    return (extract_image(pdf, xref) for xref in xrefs)
 
 def nfc(s):
     return unicodedata.normalize('NFC', s)