dialog for adjusting colors in selection (HSL, brightness/contrast,etc)

[Fishb8]

Often I find that the colors I'm using for different
shapes are not quite what I want. The problem though is
not so much to do with the color of a single object,
but the image as a whole, or at least multiple objects.

Going through and changing the individual color
settings is a pain, and since my output is usually a
raster image, I just finish up and then adjust the
color of the image as a whole using color tools in
Gimp. This is nice because it gives me the type of
control I need. But it comes back to bite me in the ass
when I find that I need to change something in the
origional vector image because then I have to go
through that whole process again.

Inkscape needs color tools (Hugh-Saturation,
Brightness-Contrast, Curves, Levels, etc.) that adjusts
everything at once in whatever objects are selected.

This may be absolute heresy for people working with
color pallets, but I think most people would find it
very useful when they are trying to adjust the colors
of the image as a whole.

[Horkana-users (horkana-users)]

I vaguely recall other programs like Adobe Illustrator have
various colour tools, I suspect they work a little
differently than colour tools in programs like GIMP or other
photo manipulation software. If you could specify how other
vector programs present this functionality it might prove
helpful to developers and designers when they come to
implement it in Inkscape. I'm fairly confident this would
be a lot of interest in features like these but as you have
described yourself inkscape users are quite good at working
around the problem, so I think only when these features are
implemented will people realise quite what they have been
missing.

> Inkscape needs color tools (Hugh-Saturation,
Brightness-Contrast, Curves, Levels, etc.)

it might also help if you could be more specific and maybe
help developer decide what they should work on first.
(sorry for being so vague, essentially i think this is a
good idea and I encourage you to provide more information to
make it as easy as possible for developers to get started on
something)

[Fishb8 (fishb8)]

Well the concept is the same as color tools in raster
programs, And I think the math involved would be similar as
well. It's just that instead of adjusting the colors of a
bunch of pixels, you would be adjusting the colors chosen
for fills, strokes, gradients, (others?).

Imagine if you would that of the objects you select, each
fill color, stroke color, and gradient key color, is a
"vector pixel". The color tools would manipulate and scale
these "vector pixels" in relation to each other in the same
way that raster tools do with the color of pixels in raster
images. You would use the exact same type of controls. (And
you could even have it work with alpha values as well!)

With this type of paradigm, you could probably borrow
algorithms from GIMP's color tools and apply it to "vector
pixels" without too much work.

>it might also help if you could be more specific and maybe
help developer decide what they should work on first.

The order probably doesn't matter. The four that I listed
are IMO the most useful in adjusting images as a whole.
There are other color tools available in raster programs,
but I don't think they are used nearly as much as these four.

[Fishb8 (fishb8)]

Sorry for the double post. :P

[Horkana-users (horkana-users)]

Macromedia Freehand includes a feature called "Colour
Tables" (Ctrl+U) which helps users manage colours for
target devices, be it different types of screens or printers
or other devices. It seems to provide some sort of
automatic colour management to restrict the colours used,
and possibly functionality to restrict the colours of an
existing image for certain uses. (sorry I cannot provide
more detail, I dont have a working copy of Freehand just
documentation.)

freehand also includes a color mixer:
Color Mixer panel to define colors, to adjust hue,
lightness, and saturation, and to select colors from the
System Color dialog box.

I would go on but Freehand includes a crapload of color
features. This isn't entirely surprising given how many
people would rather use a Vector graphics software and only
go to raster graphics as a last resort (see also macromedia
fireworks, it has some vector features which are better than
freehand. same applies to Microsoft Expression, ostensibly
a vector graphics program but they have rebranded it as a
raster graphics program but with lots of vector features).
Paintscape anyone?

Having said that being very specific about the features you
want should make things easier for developers, especially if
you can break things down into smaller more managable chunks.

[Fishb8 (fishb8)]

>Having said that being very specific about the features you
want should make things easier for developers, especially if
you can break things down into smaller more managable chunks.

I don't think it can be broken down to be any more specific
or in smaller chunks. :) These color tools are very common
and have a very specific use, so I don't think there would
be any confusion about what they are susposed to do or how
they are susposed to work.

It requires the following steps:

1) Gather all color values (fill, stroke, and gradient keys)
from the selected objects.

2) Send the values to be manipulated by a color tool.

3) The color values are manipulated the same way pixel color
values are manipulated in raster programs. (The only
difference I can think of is if you are working with a
restricted color pallet, the color values would need to be
"snapped" to the closest value available in the pallet)

4) The display is updated in real time so that the changes
can be previewed

5) If accepted, the new color values are applied to the objects.

6) There can be all kinds of color tools eventually created,
but the most important are: Hugh-Saturation,
Brightness-Contrast, Curves and Levels. (GIMP provides a
good source code reference for this functionality)

[Horkana-users (horkana-users)]

no worries, it is hardly worth wasting a comment to apologize
now I'm doing it too :P

it is all too easy to double submit things in Web browsers
especially if you have a strong double click habit

[Michael-gr (grosberg-michael)]

That is a very nice idea, I've often thought of the need to
have such a tool while working on Adobe Illustrator files.
For example, I'd be creating a set of icons with a reddish
color palette, and then get a request to do a similar icon
set in green. Other than change every shade manually, the
only option I got was to export to photoshop and change the
colors on a raster output. Now, Illustrator does have
something similar but it doesn't work on gradients, for some
reason. Not on CS1 anyway.

One point worth mentioning is that some selected shapes may
be using gradients that are also shared by other objects
outside the selection. In this case, Inkscape should
duplicate said gradients before working on them, so that
objects outside the selection don't have their colors
changed as well.

[ScislaC (scislac)]

Originator: NO

I know that Bulia is planning on adding at least a few of these features
in the future. In the meantime he had committed some color manipulation
effects for the next release (0.45), which can be found in the Effects menu
in our development version. The biggest issue you will probably run into
with the effects though is that they aren't realtime.

[Bug Importer (bug-importer)]

I was also thinking this too would be nice. What if you make a complete
drawing and later you noticed that the light areas are too light, or that
the entire picture is too dark, or that the blues are too green, or that
the reds are too bright?

In the new 0.45, there are some of these brightness and color controls,
but they are very inefficient. You should be able to use sliders and
equalizers.

[vonHalenbach (lustik)]

This is a good idea. I don't know how hard it would be to implement.

[bbyak (buliabyak)]

right now most of this is doable by the tweak tool, see 0.46 release notes

but i'm leaving tis open as a wishlist for a more conventional slider-controlled dialog working on selection

[Courtney Miles (cmiles)]

I just wanted to voice some support for this request, especially now with the Tweak Tool.

I've found that using the Tweak Tool to jitter the lightness of a array of objects can't produce enough contrast for my liking--even if you start with light colours, or dark colours, the lightness shifts towards the centre of the spectrum and doesn't approach the extremes (even with maximum pressure).

The ability to jitter lightness, then apply an overall contrast change would solve the issue. As it is, I don't believe there is any practical way to achieve a greater contrast across a selection of a multiple (many hundred) items after jittering them--but I would love to hear otherwise.

Attached is an example of what I can achieve using the tweak tool on the left, and the effect I would like to be able to achieve on the right.

[Pablo Trabajos (pajarico)]

Courtney: what channels are you tweaking with the tool? the example at the right has a lot of lightness contrast but the light blues seems to have a lot of saturation too, so working on the saturation may help. Perceived "lightness" is not just light but saturation too (in this system).

[Courtney Miles (cmiles)]

Hey Pablo. That left image is actually the result of playing with saturation also. But it certainly appears the saturation became a lot stronger when I changed it's contrast in GIMP--that wasn't really expected.

[Rena Kunisaki (i-am-inuyasha)]

Currently, it's possible to select several objects, and their average fill/stroke colour is displayed in the Fill and Stroke window. However, adjusting the colour sets all objects to the same colour. The most obvious fix to me is to have the adjustment be performed relative to the current colour. (This however has issues described in Bug #555017.)

[su_v (suv-lp)]

ScislaC wrote on 2006-12-15:
> In the meantime he had committed some color manipulation effects (…)

Related:
New module added in trunk for 'Extensions > Color': HSL Adjust
Allows to modify selection (or drawing) by adjusting Hue (360°, wraps around), Saturation (%) and Lightness (%)

Bug #979208 “New: Extensions > Color > HSL Adjust”
<https://bugs.launchpad.net/inkscape/+bug/979208>