colourising b/w photos with AI

If you would like to share some of your garden railway photographs or photos of prototypes which might inspire members, then please post them in here
Post Reply
User avatar
ge_rik
Administrator
Administrator
Posts: 7937
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

colourising b/w photos with AI

Post by ge_rik » Tue Jul 21, 2026 12:50 pm

I've been playing around with getting ChatGPT to colourise some Southwold Railway photos.

Eg
swatwenhaston-1.jpg
swatwenhaston-1.jpg (455.75 KiB) Viewed 1923 times
file_00000000ab2481f4a33d85101da737a5.png
file_00000000ab2481f4a33d85101da737a5.png (2.7 MiB) Viewed 1923 times

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
ge_rik
Administrator
Administrator
Posts: 7937
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: colourising b/w photos with AI

Post by ge_rik » Tue Jul 21, 2026 12:52 pm

I had to tell it that the loco should be GER blue
file_0000000033f481f4a54193b5ba8d4eb6.png
file_0000000033f481f4a54193b5ba8d4eb6.png (2.72 MiB) Viewed 1921 times

And then tell it to remove the GER lettering
file_000000006b1881f4a51cdb3c13cff450.png
file_000000006b1881f4a51cdb3c13cff450.png (2.66 MiB) Viewed 1921 times

Interesting it's also removed the caption from the original postcard


Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
ge_rik
Administrator
Administrator
Posts: 7937
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: colourising b/w photos with AI

Post by ge_rik » Tue Jul 21, 2026 1:29 pm

file_000000005f4082469e63f7a9c3dd233e.png
file_000000005f4082469e63f7a9c3dd233e.png (2.7 MiB) Viewed 1914 times
I wanted to change the colour of the loco in the shed but I've now exceeded my daily limit for the freebie processing

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
philipy
Moderator
Moderator
Posts: 6004
Joined: Sun Jan 30, 2011 3:00 pm
Location: South Northants

Re: colourising b/w photos with AI

Post by philipy » Tue Jul 21, 2026 4:15 pm

Looks good Rik. I did some playing with colourising back when I built the Chingford contractors loco, it wasn't bad but I think things have moved on since then. I actually used the colourising feature of "Find My Past" for that, which was the only easily available one at the time.

I notice on your first set of pictures that it has actually coloured the "green" spectacle in blue, which is of course correct but it could easily have missed that one!
Philip

User avatar
drewzero1
Administrator
Administrator
Posts: 859
Joined: Fri Apr 21, 2023 4:35 pm
Location: WI, US
Contact:

Re: colourising b/w photos with AI

Post by drewzero1 » Wed Jul 22, 2026 6:46 am

Looks good Rik, and that charming blue engine sure does look familiar in color :mrgreen:

I have occasionally seen anachronisms in AI-colorized works, probably due to modern biases in the training data. Stuff like coloring pants as blue jeans before they were commonly available. Just something to watch out for!

User avatar
ge_rik
Administrator
Administrator
Posts: 7937
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: colourising b/w photos with AI

Post by ge_rik » Wed Jul 22, 2026 7:37 am

philipy wrote: Tue Jul 21, 2026 4:15 pm I notice on your first set of pictures that it has actually coloured the "green" spectacle in blue, which is of course correct but it could easily have missed that one!
Yes, I spotted that.

But I've also just noticed that the spectacle on the far side of the signal ought to be showing green to the train. Clearly, some maintenance is needed. I must have looked at his picture dozens of times and never spotted it.

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
ge_rik
Administrator
Administrator
Posts: 7937
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: colourising b/w photos with AI

Post by ge_rik » Wed Jul 22, 2026 7:47 am

It let me have another go this morning so I asked it to colour the loco in the shed. Interesting result.
file_00000000251081f480388e37c67d4787.png
file_00000000251081f480388e37c67d4787.png (2.71 MiB) Viewed 1840 times
However, when I asked it to colour the face of the driver, it told me I'd reached my limit again and will have to wait five hours.

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
philipy
Moderator
Moderator
Posts: 6004
Joined: Sun Jan 30, 2011 3:00 pm
Location: South Northants

Re: colourising b/w photos with AI

Post by philipy » Wed Jul 22, 2026 8:01 am

ge_rik wrote: Wed Jul 22, 2026 7:47 am
However, when I asked it to colour the face of the driver, it told me I'd reached my limit again and will have to wait five hours.
I had that problem with Google Gemini when we first got involved with creating figures with Gemini and Meshy. I think its something to do with how they work, so if you ask it a question, or to do something, on a long or complicated thread, it has to reconstruct the entire sequence from the beginning to add to it. It may help, once you get back in, to save that picture, then start a new chat and load the picture back in and simply ask it to colourise the drivers face. No guarantees but doing that has helped me in the past.
Philip

Paul_in_Ricky
Trainee Fireman
Trainee Fireman
Posts: 167
Joined: Fri Dec 27, 2019 12:44 pm

Re: colourising b/w photos with AI

Post by Paul_in_Ricky » Mon Jul 27, 2026 8:59 am

philipy wrote: Wed Jul 22, 2026 8:01 amI think its something to do with how they work, so if you ask it a question, or to do something, on a long or complicated thread, it has to reconstruct the entire sequence from the beginning to add to it.
It's simply rationing your (free) use of the AI engine. If you were paying for access you'd continue and be using up your credit instead.

I'm not entirely convinced about recolouring old photos, ultimately it's just fantasy colours. Possibly worse is that in future it may be taken as authentic without an AI tag, with the added problem that when AI recolours an image it often makes other changes to the content as well as just colour.

User avatar
philipy
Moderator
Moderator
Posts: 6004
Joined: Sun Jan 30, 2011 3:00 pm
Location: South Northants

Re: colourising b/w photos with AI

Post by philipy » Mon Jul 27, 2026 9:51 am

Paul_in_Ricky wrote: Mon Jul 27, 2026 8:59 am
It's simply rationing your (free) use of the AI engine. If you were paying for access you'd continue and be using up your credit instead.
No, that is different.
I had a couple of instances a while back with a chat that went on over several days and got mega long and it was taking forever to respond. When I asked it why it said it was to do with the length and suggested I start a new chat. I asked how it would know where to continue and it gave me the wording for a new chat that would give it the essence of what had gone before. I tried that and the speed went back to what it had been initially. The only downside was that it had forgotten, or not recognised, some of the earlier stuff in the original chat and I did have to remind it of salient points from time to time.
Philip

Paul_in_Ricky
Trainee Fireman
Trainee Fireman
Posts: 167
Joined: Fri Dec 27, 2019 12:44 pm

Re: colourising b/w photos with AI

Post by Paul_in_Ricky » Mon Jul 27, 2026 11:08 am

philipy wrote: Mon Jul 27, 2026 9:51 amNo, that is different.
No, you're mixing up why responses get slow from why you get stopped dead and asked to wait hours for the next step. That's rationing.

Quite often 'chats' get bogged down as the AI makes mistakes, you correct/refine it's answer and it starts going round in circles. At that point you're better off just starting a new 'chat' to get the AI to start from scratch again.

User avatar
ge_rik
Administrator
Administrator
Posts: 7937
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: colourising b/w photos with AI

Post by ge_rik » Mon Jul 27, 2026 2:57 pm

Paul_in_Ricky wrote: Mon Jul 27, 2026 8:59 am ...... the added problem [is] that when AI recolours an image it often makes other changes to the content as well as just colour.
I noticed this. In addition to turning the loco around in the shed, it added an extra chimney to the roof of the cab. When I asked it to correct this and also to colour in the face of the driver in the nearest loco, it removed the original driver completely and added a driver which, to my mind, resembles JD Vance ...... It also removed the chimney of the foreground loco and changed the background loco into something weird. It's clearly trying to be too clever.
file_00000000922c81f480cd9cd9c293cb38.png
file_00000000922c81f480cd9cd9c293cb38.png (2.77 MiB) Viewed 55 times

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

User avatar
ge_rik
Administrator
Administrator
Posts: 7937
Joined: Sun Oct 25, 2009 10:20 pm
Location: Cheshire
Contact:

Re: colourising b/w photos with AI

Post by ge_rik » Mon Jul 27, 2026 3:00 pm

It begs the question, when they use AI to target munitions in a war situation, will it actually do as it's told, or will it try to be too clever ......

Rik
------------------------
Peckforton Light Railway - Blog Facebook Youtube

Paul_in_Ricky
Trainee Fireman
Trainee Fireman
Posts: 167
Joined: Fri Dec 27, 2019 12:44 pm

Re: colourising b/w photos with AI

Post by Paul_in_Ricky » Mon Jul 27, 2026 3:39 pm

ge_rik wrote: Mon Jul 27, 2026 2:57 pmIt's clearly trying to be too clever.
I think the expression you're looking for is AI Slop
It begs the question, when they use AI to target munitions in a war situation, will it actually do as it's told, or will it try to be too clever ......
The sort of dedicated AI used for 'serious' applications is a different beast from what the casual consumer gets to play with.

Post Reply

Who is online

Users browsing this forum: No registered users and 11 guests