How to colorize cobbled road

[Thomasson]

Hello everybody  
I'm interested in colorization of old photos. Sometimes I encounter a problem with cobbled roads/streets. For example this photo taken in 1930s. How to automatically colorize it without laborius selecting some stones and makinh them reddish and others bluish? Like in this color photo? https://www.dreamstime.com/ancient-windi...e103076500

[rich2005]

Depends how you are going to colorize the image. I am[ no expert, there are Gimp users around who do great work.

This using the gimp_gmic_qt plugin  http://www.gmic.eu There is a Windows installer. One of the filters is a photographic colorize, which takes an overlay of color swatches.

I tried taking a small sample, a select & copy, of your paving and used the clone tool which will paint a pattern, In this case like this + other colours.

   

In gmic

   

And the result, the cobbles not as good as hoped for but maybe with a little more effort...

   

[sallyanne]

You could select the whole area of cobblestones. Adding another transparent layer, fill it with the main colour. Then adding another transparent layer using your brush put brush strokes where you would like different colour.
Or blur squiggly marks to be quicker. the first layer would need to have opacity turned down and then put in LCH colour layer mode.

[sallyanne]

This is a initial quicky result of what I mentioned
[attachment=9457]
Colours are yours to choose. I did it with red and blue
Plus the XCF

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To give the cobblestones more definition you could also sharpen the selection (Many different ways this could be done), or copy the selection, paste as a new layer and bump (Harsher).

[Thomasson]

I did it manually. I have prepared a separate layer "Stones". Using Quick Mask and paintbrush (random selection of stones) i divided into reddish stones, blueish stones and ground between them.
   

[PixLab]

(02-28-2023, 09:25 AM)Thomasson Wrote: I did it manually. I have prepared a separate layer "Stones". Using Quick Mask and paintbrush (random selection of stones) i divided into reddish stones, blueish stones and ground between them.

Yes the stones' color look natural
If you colorize it like @rich2005 did show you, the result on a new layer, your can play with blending mode as well (this what I do) on the B&W original, just a tip if it can help

[Thomasson]

It could look mora natural but I spent only a few minutes on it. I think somebody should prepare a plugin (e.g. in G'Mic) to color the stones easy, fast and beautifully

[sallyanne]

Well done Thomasson