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Ridgerunner
03-29-2018, 06:26 AM
I saw this article (https://www.livescience.com/62153-oldest-human-footprints-in-north-america.html) and one of the photos looked like a thermal image. It did say digitally enhanced so maybe it was not. I was wondering if a thermal camera or some other modern device could help read badly weathered text on old stone gravestones?

fjk
03-29-2018, 08:36 AM
I would doubt that thermal imaging would work. There would have to be a temperature difference and I don’t see any reason for such a difference.

That said, digital manipulation seems very reasonable. There could be very slight color or brightness differences that are not visible to the eye but can be brought out by playing with color mapping, etc.

If you do try, take RAW photos to get & save the most information. Phones & similar cameras usually don’t have a RAW option. Compressing to jpeg can throw away a lot of those sub-visible differences.

A.K. Boomer
03-29-2018, 09:18 AM
How could Hosies sister have gotten way over on this side of the pond without nobody knowing? and then sneak back?

I don't think so probably just a plant with leaves shaped like a huge grotesque foot...

mattthegamer463
03-29-2018, 09:42 AM
Probably an artificially coloured output from a 3D photogrammetry rig. Using a handheld 3D scanner which tracks its own position with internal/external sensors and uses two imagers to sample laser light fired at the subject, it uses math to create a 3D topographical model of the item/surface it is passed over. The results can be manipulated for visual purposes such as in this case to accentuate the topography of the footprint.

Stuff like this;
https://3dscanexpert.com/beginners-guide-3d-scanning-photogrammetry/

Similar things can be done with a single camera and specialized lighting to capture shadows at many angles, then compute the topography of the object with special software.

Reflective Transformation Imaging is really interesting stuff but I've yet to find a HSM use/excuse to build one

https://hackaday.io/project/11951-affordable-reflectance-transformation-imaging-dome

sasquatch
03-29-2018, 03:22 PM
I alway have to chuckle some at some of these age predictions. Like if they can accuretly say these are 3000 years old or whatever, (you see these predictions posted as accurate facts with stuff like mummmies etc too, ) then if these are that good, instead of exactly 3000 years old, why not 2290, or 2051? Lol

danlb
03-29-2018, 03:33 PM
I saw this article (https://www.livescience.com/62153-oldest-human-footprints-in-north-america.html) and one of the photos looked like a thermal image. It did say digitally enhanced so maybe it was not. I was wondering if a thermal camera or some other modern device could help read badly weathered text on old stone gravestones?

That's a good question. I have a FLIR camera for my cell phone. If you can think of a way to test it, I'll try to get it done. I'm thinking that maybe a heat lamp that is offset might provide heating based on elevation. Probably not. :(

If nothing else, I can drop by the old cemetery and see what I can pull up from the 1800s era headstones.

Dan

MattiJ
03-29-2018, 04:39 PM
That's a good question. I have a FLIR camera for my cell phone. If you can think of a way to test it, I'll try to get it done. I'm thinking that maybe a heat lamp that is offset might provide heating based on elevation. Probably not. :(

If nothing else, I can drop by the old cemetery and see what I can pull up from the 1800s era headstones.

Dan

Thermal imager is just turning the black-and-white image to rainbow color palette in software. Pseudocolor high contrast presentation of black and white picture. Thermal imager photos are "colorless" without extra processing.

I did this lathe picture by just clicking "thermal effect" :
https://i.imgur.com/ax5kfY9.jpg (https://lunapic.com)

MattiJ
03-29-2018, 04:45 PM
added bit of contrast to the original picture and turned on "thermal effect on lunapic online photo editor:
https://i.imgur.com/uLuAtns.jpg (https://lunapic.com)

Peter.
03-29-2018, 05:05 PM
I alway have to chuckle some at some of these age predictions. Like if they can accuretly say these are 3000 years old or whatever, (you see these predictions posted as accurate facts with stuff like mummmies etc too, ) then if these are that good, instead of exactly 3000 years old, why not 2290, or 2051? Lol

Because 2051 suggests that they claim to be accurate to 1 year and 2290 to 10, whereas 3000 suggests "about 3 millenia".

danlb
03-29-2018, 05:11 PM
Thermal imager is just turning the black-and-white image to rainbow color palette in software.

Well, that's one way to do it.

I have a thermal imaging camera that will take a picture using the infrared spectrum and then map that image in several different ways for interpretation. FLIR is Forward Looking InfraRed .

Your lathe picture shows your compound as hotter than the headstock. What are you doing to that poor lathe?

Dan

MattiJ
03-29-2018, 05:58 PM
Well, that's one way to do it.

I have a thermal imaging camera that will take a picture using the infrared spectrum and then map that image in several different ways for interpretation. FLIR is Forward Looking InfraRed .

Dan

Yeah, but the point was that the thermal imager image is originally monochrome just like black-and white pictures are. (compared to color cameras that take images at 3 wavelenghts.)

lakeside53
03-29-2018, 06:01 PM
Well, that's one way to do it.

I have a thermal imaging camera that will take a picture using the infrared spectrum and then map that image in several different ways for interpretation. FLIR is Forward Looking InfraRed .

Your lathe picture shows your compound as hotter than the headstock. What are you doing to that poor lathe?

Dan

He has a heated brake bar for his poor feet too ;)

MattiJ
03-29-2018, 06:01 PM
Your lathe picture shows your compound as hotter than the headstock. What are you doing to that poor lathe?

Dan

If that would be a real thermal image I would interpret it as a reflection in highly polished aluminium compound parts from something hotter in surrounding. ;)

Edit: brake bar has to be polished shiny with thousands of small chips embedded in the soles :rolleyes:

Ridgerunner
03-29-2018, 06:47 PM
Thanks for the replies. You guys are terrific. Mattthegamer463's links sent me down the internet road to finding that Carnegie Mellon University in Pittsburgh, Pa was doing this work in 2007 from this BBC article (http://news.bbc.co.uk/2/hi/technology/7024672.stm). I don't know if their work ended in a commercial product or not, but from the pictures it looked pretty impressive.