I had not planned to write about the birth certificate controversy until later in the week, but a post in No Quarter
forced the matter. In essence, Obama's critics have argued that the COB (certificate of birth) must be a fake, since it lacks the embossed seal and the stamped signature visible on a real COB and mandated by law.
Obama's defenders argue that edge detection software has found just such a seal.
The problem is this: Someone at Kos pulled a fast one. Without telling the reader, they replaced their original scan of the COB with a new scan.
The original -- which I saved to my system the day it first appeared -- is 1024 pixels by 1000 pixels in size. It was saved with a very lossy compression scheme, which is why you can see all sorts of jpg artifacts surrounding the letters. (Those artifacts tend to cluster in areas of high contrast and around the color red.) You can find the original scan
here.
Kos has subtly replaced this scan with a
much larger one, 2427 pixels by 2369 pixels. The new scan is much less lossy, so you'll see far fewer jpg artifacts.

The new scan has the same name as the original: BO_birth_certificate.jpg. The original Kos post -- the one which introduced this COB to the world -- now points to the
new scan, without telling readers that the image has been replaced.
Very sneaky. And indefensible.
According to the No Quarter story, the seal (but not the stamped signature) is now visible on this new scan. To see it, they suggest using the free image software GIMP.
Now, GIMP is an extraordinary piece of freeware, and it does allow one to achieve professional results. However, the industry standard is Photoshop.
Using that software, I've been able to attain a clearer view of the "occulted" embossed seal, simply by using the "Find Edges" filter under "Filter/Stylize." The results are here.
Using the same technique, one can also see the fold in the paper, which runs through the state seal at the top. This fold indicates that we are, in fact, dealing with a scan of a piece of paper, as opposed to an image that was created electronically.
Yeah, but...The writer at No Quarter, TexasDarlin, considers the fact that we are dealing with a
new scan to be a "red flag." As indeed it is.
We all know that Kos and the Obama campaign have achieved an obscene closeness. How do we know that they have not tossed a ringer at us? How do we know that the new 2427 x 2369 scan isn't an extremely clever fake?
TexasDarlin applied the same GIMP software to the ORIGINAL scan. And guess what?
No seal.
Is that it? Have we proven that the Kos crowd has tried to fake us out?
I am very sorry to report that the answer is
no.

As noted above, GIMP is not the industry standard. As noted above, the original 1024 x 1000 scan is smaller and lossier. It is MUCH harder to pull "hidden" information out of a small, heavily compressed image. So let's subject this image -- the original image -- to Photoshop.
If you use the filter described above ("Find Edges"), you'll get nothing new. So you have to use another filter, called Glowing Edges. This allows you to play with three slider controls. After experimenting, I found that these settings worked best:
Edge width 1, Edge brightness 9, Smoothness 1
Et voila! You do see a very faint, but definitely CIRCULAR impression. In the exact same spot. In the ORIGINAL Kos scan. (To increase visibility, I also adjusted the Image Levels.)
I am a little limited as to what I can display here, since Blogger will shrink images if they are larger than 400 x 400. But I'm not asking anyone to take my word on faith here. Many people have Photoshop and they can repeat the experiment.

I also was able to see evidence of the fold in the original scan.
Have we answered all questions? No. Here are some lingering mysteries:
1. Genuine Hawaiian COBs also have a stamped signature on the back. None appears on Obama's COB. Why?
2. How can Kos excuse replacing the image with a more detailed scan -- and not telling readers what he has done?

3. Obviously, the physical piece of paper must exist. Someone placed it on a scanner. Where is it, who has it, and why is it not available for independent examination?
I hope that I've explained the situation clearly. In the past, when this blog has tried to discuss technical matters, a few readers have wildly (willfully?) misinterpreted my arguments. I encourage people who own copies of Photoshop to repeat the steps taken here.
UPDATE: You can in fact see the seal in the original using GIMP (the freeware program anyone can
download). Go to "Edge Detect" and then use the "Roberts" filter. You'll have to play with the amount to get the best result. It is VERY faint, but you can see it.