Weird 1-pixel images

Hi Aspose,

I faced with unclear situation and need your explanation. I have scanned document with some weird images - Adobe Acrobat shows boxes around them:
boxes.png (5.9 KB)

Aspose.PDF also detects 4 images. But when I want to extract them via Adobe Acrobat, it says following:
noimagestoextract.png (5.5 KB)

After deep investigation I’ve noticed they are 1-pixel transparent images, so assume Adobe skips them because of this.

Please explain what they are. This is sample document (72.0 KB)

Best regards,
Alex Shloma

@licenses

Thank you for contacting support.

We have been able to notice same images in shared PDF document. A ticket with ID PDFNET-45822 has been logged in our issue management system for further investigations. The ticket ID has been linked with this thread so that you will receive notification as soon as the ticket is resolved.

We are sorry for the inconvenience.