"Martin K. R." wrote:
Maybe this is a shot in the dark, but I’ll try anyway:
I’m looking for a Photoshop plug-in (or maybe a separate program) capable of reckognizing and enhancing VERY faded – almost invisible – handwritten text on old documents (150-200 years old).
I’m aware of a filter plug-in from Reindeer Graphics (the Adaptive Equalization filter), which is a step in the right direction, and I can manually fiddle with the Gamma curves and contrast/brightness controls in Photoshop. This enhances the individual pixels a bit, but I need something to ‘connect the dots’ or to show that ‘these pixels could be part of this line’. Maybe a bit like an OCR program, but more simple – only detecting fractions of lines and curves or similar (because it’s handwriting, not printed text).
You don’t really want to go this route — fiddling with curves, levels, and brightness/contrast on a scan that has almost no contrast to begin with will introduce a lot of digitally induced artifacts amplified in a "threshold" effect…
Does such a plug-in or program exist?
You can probably create actions out of the tips below…
Links to plug-ins/programs that could point me in the right direction are also highly appreciated.
Thanks in advance,
Martin
3 simple, non-destructive ways to enhance "faded" details:
1)
double-click on the foreground/background color swatch in the main tool palette and restore black/white colors.
at the bottom of the layers palette, click on the half-light/half-dark circle (new adjustment layer) and select "Gradient Map" (NOT Gradient)
from the gradient map popup — click on the gradient itself to pop up the gradient editor
around the gradient, there will be 4 "stops" — one at each corner… click and drag the bottom left stop far to the right and release — observe the effect on the image… keep adjusting until you have a desired setting…
click out of the popups…
You should be able to find the detail you’re looking for… and your original is not altered in any way.
if you can only get the faded text to "come up a little" — then duplicate the gradient map by dragging the layer onto the new layer icon — the difference should be very dramatic.
2)
set the foreground color to black
create a new layer in "front" — set the blend mode to Color Burn
paint over the area (scribble, select & fill, etc…) to bring up the text [option delete on a mac or (probably) ctrl-delete on a pc will fill the layer with the foreground color…you don’t have to select anything]
3)
(similar, but less ugly)–
set the foreground color to black
create a new layer in front — set the blend mode to overlay
paint (or fill) over the area
The effect will be subtle, so…
click on the overlay layer in the layers palette and drag it onto the New Layer icon at the bottom of the pallete… this will produce an exact copy of the overlay layer… Repeat this process until you achieve your desired result.
more tips:
You can combine the multiple duplicates of the adjustment layers by clicking on one in the layers palettes and linking the rest… then from the palette menu, select Merge Linked… If you’re satisfied with the result and want to alter the original image, you can link it in as well.
Instead of increasing the contrast of your original, and if you need to "sharpen" the text a little [or increase a "focus" effect]:
duplicate the original scan layer [drag the layer onto the new layer icon]. Go to Filter/Other/High Pass.
in the popup, start with a value of 1.4 (approximately the square root of 2 — this is the BEST first guess) [or type into the text box:
1.4142]. click okay…
change the blend mode of the layer to overlay… duplicate this layer until you have acquired better edges sharpness (this is very subjective).
You can (and probabaly should) do this step after the adjustment layer trick above and place these layers below the adjustment layers in the "stack".
Using these techniques, you should have considerably LESS threshold-like artifacts in the final image.
if all else fails:
you may need to rescan your images and adjust the hardware (scanner settings) so that the exposure light doesn’t "fade out" the text as much
[this may mean an overall darker original].