Originally posted by Thermo Klein
Mara Zebest is no pseudo expert
she's the one who wrote the book, LITERALLY, on how to use PhotoShop. She verified the document from
White House .gov is in 5-layer PhotoShop format with obvious changes to several different areas.
Mara Zebest wrote
a book about
Photoshop...her and a gazillion other folks.
The Birth Certificate that the President released for internet purposes was an
Adobe Acrobat PDF file, which Mara seems to know nothing about.
Specuifically how Adobe compresses imagery.
Her unqualified analysis has been debunked by several people who actually do have expertise with Adobe Acrobat.
This person suummed it up well, but there are plenty of other identical debunkings by genuine Adobe experts for anyone willing to shake the birther
fog from their mind..
When we look at all of these elements together, we can make a few guesses about what sort of artifacts we would expect in the PDF. First, we note that
it is quite possible that parts of the text may be represented by different encoding schemes. In figure 5, for example, Zebest points out that the
'4' and the '1' in the serial number appear to be different. Zebest is here comparing apples and oranges - the '1' was assigned to the color
layer, and is encoded using a multi-bit color mapping, while the '4' was compressed with JBIG, and is thus monochrome. The 'noise' that Zebest is
talking about exists only in her mind.
We would also expect that some symbols would be repeated. In figure 6, she notes that the 'i' is identical despite appearing in two different
places. As we have seen, this is due to the compression algorithm deciding that they are similar enough to represent with the same symbol. This
phenomenon occurs quite frequently in the compressed image - even the '1st' and '2nd' checkboxes in section 4 of the document were replaced with
the same symbol, but the '3rd' was not. This strongly indicates that the duplicate detection was done via software rather than a human agency.
In short, by being ignorant of the manner in which image compression works in PDFs, Zebest's analysis is completely useless. Most of her points are
irrelevant, and thus the "forgery" accusation remains unproven.
www.amazon.com...