Questions tagged [curves]

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2answers
71 views

Do curves in GIMP have “targeted adjustments” like in Photoshop?

Is there a targeted adjustment feature in the curves settings of GIMP. To set colour curves. Like in Photoshop?
2
votes
1answer
89 views

What change does tone curve make in pixels in a colored image in Photoshop and Lightroom? [duplicate]

As I understand it, when I make a change in the tone curve in Adobe Photoshop (or Lightroom) and have selected the RGB Channel option, the following happens: For every pixel in the image, if any of ...
2
votes
2answers
146 views

Why does Photoshop Curves in 16 bit color depth still use tonal range 0 - 255?

I am wondering why does Photoshop use tonal values in range 0 - 255 while i'm working on an image of 16 bit bit depth, because in this case each color channel doesn't use 256 tonal values but 65536. ...
2
votes
1answer
143 views

What is the difference between Photoshop RGB Curve and Lightroom RGB Tone Curve?

I am very confused with the following situation, let's say we have an image with two colors: (RGB 0,60,60) and (RGB 255,0,0). I have noticed that the tone curve in Adobe Lightroom works differently ...
4
votes
1answer
165 views

What does “normalizing the curve” mean?

A colleague mentioned a course in digital signal processing where he remembered the expression "normalizing the curve" or "normalizing the image" to make it as accurate as possible and get better ...
0
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2answers
210 views

Is it possible to simulate any color-only filter with curves?

In this question it was asked whether it was possible to reproduce any color-only change to an image using just curves. In my answer, I said that there were color-only changes such as conversion to ...
3
votes
2answers
202 views

How to find curve that correspond to a given transformation?

I am having a little bit of a mathematical approach here... I suppose that all the transformation we can make to an image which operate on one pixel per time (for example levels, saturation, color ...
3
votes
3answers
9k views

What's the best method to change colours in a photo to another specific color?

What is the best way to change the colours in a photo to a specific colour? Specifically, how can we change the colours using Curves or Levels Layer? Here are few examples for understanding: orange ...
9
votes
3answers
896 views

What is the difference between levels, curves and contrast settings in post processing?

I have found and read a lot of tutorials that speak individually about curves, levels and contrast in post-processing but no luck so far about finding something that compares them. It is my ...
0
votes
1answer
103 views

Programming curves tool how to work with RGB (combined) channel

I'm working on a Curves tool and i need to adjust all three channels at once using one curve. (RGB Curve) Internally, the class i created for the counting gets a set of control points the curve ...
4
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2answers
1k views

How to fix the exposure of a snow scene which came out gray?

I’ve got a video and a photo shot in the same day and same place. But my camera (GoPro Hero 3, 720p) doesn’t allow to customise settings and video is very poor quality. I tried to fix this using ...
12
votes
3answers
815 views

How are the levels and curves tools related?

I started to use levels and curves tools quite recently and now I mostly use the second one. Mostly this is due to the fact that I understand the underlied mathematics of curves better than levels. My ...
6
votes
2answers
159 views

How do objects in the dark come up when post processing?

I took one shot of oil lamps. Partial metering mode was used and I focused on the bright yellow light, as expected the image was captured with only the light and its immediate surroundings visible. ...
0
votes
4answers
554 views

Does the curves tool in Photoshop (or any software) do anti-aliasing?

I'm not talking about drawing smooth curves here, but rather the curves tool used for adjusting color levels. An illustration will be worth a thousand words, here. This is an adjustment in Gimp: ...
5
votes
2answers
2k views

What is a “Slanted S” in a curves layer?

I am trying to do a Photoshop tutorial, seems easy, but I can't understand one phrase: `First, I add a curves layer and create a slanted S. What does slanted S mean? Maybe I should "write" S in curves ...
4
votes
2answers
886 views

How to interpret various curves present in post-processing applications?

Could anyone to explain me or point me to some resource which explains how to interpret various curves in post-processing applications ? I'm using UFRaw, and RawStudio.
2
votes
2answers
2k views

Is there a way to get Gimp to use color curves from a Technicolor CineStyle S-curve lookup table?

Is there a way to import a Technicolor CineStyle S-curve lookup table in Gimp->Color->Curves? The lookup table is just a text file with 256 lines, with a numeric value (0..255) on each line: 0 .....
2
votes
1answer
1k views

How exactly do RGB curves work and interact w/each other in Photoshop?

So I understand how a single curve works: If you create a curve such that R100 (in) becomes R50 (out), every pixel that has an R value of R100 becomes R50. Similar deal with the RGB curve: if you ...
9
votes
1answer
2k views

In ufraw, how to use the two curves?

I have a basic understanding of curves. That is, I know the mathematical concept behind them, and I have an idea what happens when I change them. But this knowledge came from sources which assumed ...
13
votes
2answers
4k views

How does the Curves tool work in GIMP?

I started using GIMP recently, and came across an option called Curves under the Colors menu. What does this tool do, and how do I use it correctly? I get some good colors if I make a graph in 'S' ...
10
votes
2answers
313 views

Preserving texture in shadows with levels/curves

I have the following image, and I would like to preserve a little bit of texture in the shadows. As you can see (hopefully), the darkest parts of the image have gone to a solid black. There is some ...