Thoughts on how to enhance an image Options

[PFK]

Folks
This is certainly unrelated to UMSF (and I assume therefore not best placed in the image processing sub forum) but on the other hand is something that the massive collective experience and prowess of this place should be able to provide pertinent thoughts on (indeed I'm kicking myself for not thinking of asking earlier, having spent so long marvelling at the images generated here).
Take the following image:



It's actually faint text, and in fact should read the football results thus:
Arsenal 0 Sunderland 0
Aston Villa 0 Chelsea 1
So my question would be what techniques might best be used to manipulate such an image to make it as legible as possible?
The limit of my Photoshop ability is a simple contrast enhancement, but presumably we could be much smarter than that?
Why? I hear you ask....well it harks back to work we published in Chemical Communications last December where we showed that polymerisation of disulfur dinitride is stimulated by inkjet traces. Thus minute amounts of the latter prompt the formation of the dark polymer (SN)x; minute amounts such as the residue on the inside of an envelope which has contained an inkjet printed page. Thus in the above case the results from one saturday were printed out, placed in an envelope and then sent to ourselves. Upon opening the envelope and discarding the printed page, the inside of the envelope was exposed, part of which gave the image shown (which I have reversed from the actual mirror image generated).
This is one of the poorer examples, but I guess that makes it even more useful to work on.
Any thoughts welcome!
Thanks
PFK
PS What's even spookier is when you can image the contents of the envelope without opening it thanks to the even more minute amounts of inkjet diffusing right through - but that's another story

[Juramike]

Here is a difference image between Mark8c and Marck9. (Looks like a chunk shifted down and to the right between 8c and 9)

[Juramike]

Animated GIF cycling through original (darker)-->Mark8c-->Mark9:

(click to animate)

-Mike

[Juramike]

And now, one last blink comparing the (B&W converted and contrast stretched) original lettering, with my processing from mark9 hi-res:

(click to animate)

The "V" is definitely visible, the "illa" and "0" can be seen with some imagination, and the "d" in Sunderland is also evident.

Spooky.

[PFK]

Excellent stuff Mike, thank you !

[PDP8E]

Here is the second high res image (converted to grayscale)

Same technique - all images done the same way:
* adaptive rank order filter to median-out serious outlier pixels in a kernel
* then a few different sizes of a histo-equal filters run over the image to do smart contrast
* summed in the output image and finally averaged by pixel -
* run time is 2 secs per big image on an old laptop,
* using just a home brew c++ program to do the processing
* the 'gray edges' are the original image at the bottom of the average stack.




Mike: awesome blinks !
Jekbradbury: nice color work - I like the de-correlation stretch maneuver - I am looking into that....!
I invite anyone to further process my images in this thread if they want to - hopefully some one can pull something more out of them

PFK: thanks for the interesting background story and challenge.

Cheers

[jekbradbury]

I wonder how useful it would be to apply one of these greyscale techniques in conjunction with a decorrelation stretch; there is definitely a significant amount of information hidden in the differences between the color bands, but noise-removal techniques would help bring this out. PDP8E, could you try applying your technique to all three bands of the input image separately and see what happens, either in RGB or YCbCr space?

[PDP8E]

jekbradbury,

I am on it!
back in a day or two....

[PDP8E]

OK...I took the last big color image and took it apart into color bands (RGB)
* I applied the same technique above (noise reduction, and then histo-equal via stochastic stamping) to each band independently
* then put the RGBs back together in one image



and then I did the same without the noise reduction



cheers

[PFK]

again, fascinating stuff - thank you!