posted on Nov, 4 2015 @ 12:08 PM
originally posted by: trifecta
originally posted by: AdmireTheDistance
I don't see anything of interest in the areas you circled....
I've begun to realize that unfortunately. That's why I'm hoping some good digital/forensic filters could do the job in bringing out the reds and
purples.
Hiya.
The reds and purples that you're maybe looking at are the result of color channels. Is a lot better places and people to learn off thank Pinke, but
lay person crash course:
Imagine your image consisting of three layers: red, green and blue aka RGB. These layers are separate and then are merged together. Your camera
captures a different amount of data within each layer. Not all layers capture the same ratio of data. So you might capture 4 parts red to 2 parts
green to 1 parts blue for example. To write this as a ratio we would say 4:2:1.
In this case:
Red Channel:
Green Channel:
Blue Channel
The purple part of your image is due to the combination of blue and red channels. Blue channel is noisy, red has picked up some light, green doesn't
care. Purple happens. Your camera is not your eye and vice versa so oddness ensues.
originally posted by: trifecta
a reply to: AdmireTheDistance
I too have photo shop and various image editors between my PC and phone. It needs specific hardware and/or programs for the white glove
treatment.
Photoshop is actually admissible in court with the proper preparation.
The maths used in forensics programs aren't 'special maths' for the most part. Photoshop usually has more tools than forensics applications, and the
tools that are shared often use similar or even same maths. Forensics applications for the most part streamline processes, automate reports, idiot
proof, and cut down on the clutter.
The reason certain tools or formula don't reach Photoshop in their current state isn't because the tools are secret. They are often open source. It is
because:
1. Forensics don't care if there are artefacts, Photoshop users do
2. Photoshop users are in the market of using the clone stamp, not detecting it
3. Photoshop users don't care about DCT / PRNU / statistical analysis of their pixels
Hope it helps.