Photoanalysis Question

I hope that this is the proper place to be asking this. If not, I'm sure that someone will let me know.

Anyway...

Awhile back a photo was posted in the following thread:

Thread1

When I magnified the photo and took a look at the object in question I saw that it was inside a 16x16 block of pixels. My first thought was that it must be a cut & paste job. Other members advised me that this is not necessarily indicative of a cut & paste and that it had to do with the way that JPG's render the borders between light and dark areas in 8x8 pixel segments. Thus, since this 16x16 block is a multiple of 8x8, it is just the way that JPG's are compressed.

Now we come to the photo in this thread:

Thread2

When I magnify the object in this photo I do not see it enclosed in the same kind of pixel block.

Would the reason for this simply be that the photo in Thread2 was taken with a higher quality camera? Or might there be some other reason.

Thanks in advance for any and all replies.

I actually have no definite idea. But perhaps they were compressed differently, if that is even possible? Or perhaps #1 was a cut and paste and the person who told you otherwise was incorrect.

But either way, good find and great attention to detail.

To me it's more to do with size of image or how it was sized and created. All the image is trying to do is move from light to dark, and give the best color per pixel, and at times you get blocking.

This was a big factor in the 96 Mexico city footage where all sorts of people were saying the blocking proved it a fake. What proved it a fake was poor camera matching, not the blocking. The blocking wasn't present in the film, but in the captured stills...the jpg stills.

This is why you try and get the most pristine data you can.

Originally posted by Noscitare
Would the reason for this simply be that the photo in Thread2 was taken with a higher quality camera?

Impossible to tell, since most pictures on the internet is run through some sort of Stupifying Filter (a Photoshop addon?).

People constantly post heavily compressed jpgs or portions of jpgs and go OMGWTFPROOF!!!

Well here's some news for them: ITS IMPOSSIBLE TO DO PROPER PHOTOANALYSIS ON A JPG!!!

What we want:
- RAW format (or TIFF)
- 100% crop (obviously to cut down RAW size, but a link to the original would be nice too)

And that's it, two little points. Ever seen it posted? I havent.

As an example:
Lets say you take the *perfect* shot of a UFO at point blank range, but the sun is behind it and when you look at the JPG, its all black. Well pooh. It aint ever gonna be anything but black even with manipulation, cause JPG compression has decided its black, period. The information is lost forever. With a RAW, you could try to recover that information and hopefully get detail out of the "black" zone, because RAW takes your picture at a much higher dynamic range and totally without compression.

[edit on 15-12-2007 by merka]

Thanks for that reply, merka.

I'm far from being an expert in digital imagery but I have read a bit about the RAW format. It's usually an option only on higher end cameras, correct? I've just got a little Canon A540 and as far as I've been able to tell there is no option on it to save in RAW format.

Again, thanks for the info.