Palimpsest reading

[Konstantinos_Terzopoulos]

Hi!

I have photos of a 8th/13th palimpsest that I would like to decipher

Can I use Photoshop to make the letters in the background more pronounced?

Or, alternately, make the black letters in the foreground fade away?

Thanks!

k

[bzareenk]

Both the yellow and black text are overlapped on each other which will make it very difficult to read, you can try increasing the saturation of the yellow text and decreasing the blacks.

something like this.

[Konstantinos_Terzopoulos]

raising the saturation of the yellows is very helpful, but I don't know how to decrease the blacks(?)

also, when I try to use Select Color Range, there are points in the preview box where the background text goes white and everything else is darker. when I click OK from there, though, it is all gone and not knowing Photoshop hardly at all I don't know how to recreate that.

[davescm]

You can take the black out and reveal what is behind it. However you can bring out the contrast of the yellow whilst reducing that of the black so that the parts of the yellow lettering that are visible are more easily seen.

Try the following

Make a copy of the red channel (which brings out the contrast of the black against the rest).

Switch that channel so it is the only one visible.

Increase the contrast with curves then set a brush to Overlay blending mode at 50% opacity and brush with Black then white. This will sharpen up the image

Now make a selection from that channel and add a color fill layer with the color set to white and that selection as a mask. That will turn the black letters white.

Now switch to the blue channel and make a copy of that channel.

Switch to the duplicate blue channel and adjust the curves and use the same black and white painting technique. this will bring out the yellow lettering as black

Make a selection from the blue channel

Now do the same with the curves and overlay brush that you did on the red channel.

Not perfect but it may help alongside the original

I hope that helps get you started

Dave

[Konstantinos_Terzopoulos]

I don't know what contrast with curves means!

[davescm]

https://forums.adobe.com/people/Konstantinos+Terzopoulos  wrote

I don't know what contrast with curves means!

Use a curves adjustment (image - adjustment - curves) click on the line to add points and drag them. The steeper you make the curve the higher the contrast

[Konstantinos_Terzopoulos]

okay, now you say make a selection from that channel.

do you mean with the marquee tool?

what am I selecting?

[davescm]

Hi

With the channels panel open and a channel selected  Click on the dotted sircle at the bottom of the panel to turn the channel into a selection

Dave

[Konstantinos_Terzopoulos]

Okay. Thanks.

Got the curves.

But when I chose brush, overlay, opacity 50%, but I only get a circle with a line through it!

[davescm]

Can you show a snapshot of your layers and channels panels when you are trying to use your brush

Dave

[Konstantinos_Terzopoulos]

[davescm]

That screenshot shows you are trying to paint with the history brush

With the channel selected in the channels panel use a normal brush (click and hold on the pencil tool and you will see the brush shares the same slot).

Dave

[Konstantinos_Terzopoulos]

okay. found the brush, but i don't see how to set the color to white for the color fill layer?

[davescm]

Hi

That menu selection is just to pick the color for the layer panel not for the color area in the image:

You want menu  Layer > New Fill Layer > Solid Color

At the dialogue leave color set at none and click OK

The color picker will open where you can choose white

Dave

[Konstantinos_Terzopoulos]

Okay. Now the color fill layer I get under Layer>New Fill Layer?

[davescm]

Hi

Yes, use Layer - New Fill Layer - Solid Color

Dave

[Konstantinos_Terzopoulos]

do i check "Use Previous Layer to Create Clipping Mask"?

[davescm]

No, don't check that. As long as you have you selection made then the mask will be added based on the selection.

Dave

[Konstantinos_Terzopoulos]

Well. Somehow I've ended up with the exact opposite result!

[davescm]

The result is visible if you turn off all channels except "Blue copy".

To make that into a separate layer  which is visible at all times:

Add an empty layer at the top

Switch channels so only blue copy is switched on and click on the Load channel as selection icon

The rest of the channels by cicking on RGB

Go to your new empty layer

Edit -Fill - Black

Select - Inverse to invert the selection

Edit Fill White

You will now have a new layer that you can view without switching the channels on and off

I sent you a PM with a link to the PSD file I created when I did the posts above - hopefully it will help you

Dave

[Konstantinos_Terzopoulos]

I'll try that, although I think it sounds like what I did anyway.

In the mean time, as it is obviously you know how to use Photoshop (I am simply a researcher working with ancient texts), could you please tell me how I can simply emphasis the color of the underlying letters?

I tried using Color Range, which gives me great previews (!!), but once I click Okay I am left with some selected areas.

Believe it or not, the best results have been reading off these previews. I'm attaching some of these in the hopes you can tell me how I can actually achieve this and save them as images without having to work with previews, which are lost once I click out.

All best,

k

[davescm]

If you can make a selection of what you want (using color range or channels or whatever other tools you choose):

Create a new empty layer.
Make your selection using whatever tools you want

Switch to the empty layer

Use Shift+F5 and fill your selection with black

Invert the selection (Shift+Ctrl+I)

Use Shift+F5 again but this time fill with white.

That will give you a new layer based on the selection you made

Dave.

[Konstantinos_Terzopoulos]

I don't know how to "make the selection I want".

Once I click okay in the Color Range weird stuff, random parts, some of the letters and parts of the folio are selected.

The point is, as you can see from the images I sent you, while I am in the preview of the Color Range options I see the entire image exactly as I need it to read.

Why can't I recreate and save the image just as they look in those preview images?

[davescm]

Hi

You can. Color Range is just making a selection.

To use that selection and make a black and white image layer from it use the steps I gave you in the last post which was to fill an empty layer using your selection from color range with one colour e.g. black then invert the selection and fill with the opposite colour i.e. white. That will fill the layer with pixels ranging from black to white according to the selection you made with the color range tool.

Dave