Thank you akros. you did a good job considering it is an old photo (1970's) and not a digital.

Sorry, no success.
Attached is the result of my script, no tuning enhanced it appropriately; it's not really -imo- a question of "stretching"

@SallyAnne

nothing to do with the script
a little exercise to improve -my way- your photo

Hi dinasset, I wish you luck in your project with the script. Because I know we all will be able to benefit from it so much. In my opinion it's already a very good script.

Thanks, Issabella.
Still playing.
Attached is one of your photo, for an evening glamour.



ps: I'm not changing the horizon line, I'm sure you'll be able to do it yourself, but if you prefer me to do, let me know

Thank you dinasset, much appreciated.

Thank you so much dinasset, I like it as it is. You improved it much more I could wait for. Good job

Looking at the histogram, it is obvious that there is no way you can stretch the color s on the "light" side. There is a bit of room in the darks, but mostly the white are completely burned out, and this creates "sensor blooming" (the haze around the white shirts). You can do something with curves, but it's far from automatic.

SallyAnne: thanks, my outcome is not at a really acceptable level, I'm not very expert on adjusting critical old images (also my old images look -after editing- not very nicer than the originals...). Here around there are better photo "manipulators", but it seems that about photo manipulation there is some scarcity in Gimp-chat postings (compared to text manipulation, for instance...)

Issabella: it was my pleasure to "simulate" a coming evening while stretching, it looks always somehow "romantic..."
but, just in case you prefer a "night-is-coming" view, here it is....

Ofnuts
Yes, it was also my feeling that -talking here of a script which only uses values and colors stretching- nothing better could have been done.
Maybe, in the future, other techniques may be exploited, but -exactly as you say- curve is not an easy field for automatisms

It's a pity really because I would give photos a go at retouching if people wanted them done. Gimp is able to do it but it seems (as you said) there is some scarcity even for photo manipulation.

SallyAnne,
I can try to do something for your photos, if they are in a ... little better state as the one you posted here for my stress test!

Stretching color is a fairly rare correction since it implies that the whole range of possible colors isn't used in the original picture. But in general, the problem is that the original scene has a bigger dynamic range than what can be captured by the sensor (on 12 or 14 bits fro good cameras) and even more so when the output is a JPEG (8 bits) (like the group of African people above). What you want to lose to fit the sensor dynamic has to be chose when the picture is taken, so the best place to obtain a good photo is the camera. Nothing beats adequate exposure measurement and paying attention to lighting details when taking the picture. Pro photographers also use DSLRs for a reason. The much bigger sensor, where each photosite has about 10 times the area of what you get in a compact camera (and even more compared to a smartphone) has a much greater dynamic range.

Thank you so much dinasset, I appreciate much your new version on the photo. I love it in that way too. It seems to be getting dark really! Wow, you can do to be day or night. Well done!

Sallyanne, has been a pleasure!
I always confuse the Sallyanne and Issabella. You girls guys are sisters?
I do not remember who posted what or who said this or that. Must always go check out.

Issabela, my attempt,

Nice picture with beautiful smiles!

..they are nice girls (not guys) ... hehehe

Thx dinasset,
I thought "guys" could be used for both.
Thanks for alerting me!

Akros, we are not sisters but we get along great. , well, to be honest I must say that Sallyanne has much more artistic talent than me.
Your try is very good. I like it very much. Thank you so much.

Hay is this what I'm looking for?

Is the value stretching disable-able?
And is the amount of colour stretching customisable?

Sorry if I'm asking too much I don't know how long you have been developing for, and don't claim knowledge of scripting, are these planed if not implemented yet?

Just ideas and praise
Danny

Dinasset, I think the effect of your script on Akros's picture is more than acceptable. It really made a difference in the richness of the colors. With the last picture, the improvement is not as much, but it was a bad picture and had already had some changes made on it. Looks like a good script!