Can't extract masks for this pdf

[foranuj]

I have a PDF that contains four images and I can use the apis to retrieve all the necessary image information as well as manage to extract the full images.

However, I am not able to retrieve the mask information for the page.

doc.get_page_images(0)
[(6, 0, 4772, 3183, 8, 'ICCBased', '', 'Im1', 'DCTDecode'), (7, 0, 4032, 2688, 8, 'ICCBased', '', 'Im2', 'DCTDecode'), (8, 0, 4032, 2688, 8, 'ICCBased', '', 'Im3', 'DCTDecode'), (9, 0, 4032, 2688, 8, 'ICCBased', '', 'Im4', 'DCTDecode')]

Each of these images are suggesting that the smask is 0.

sample4.pdf

Wondering what am I missing.

[JorjMcKie]

An smask value of 0 means there exists not SMask.
Which relates to the fact, that xref numbers always are > 0.