Color management: RGB values

Working mass production with Aerial Photography. 8 bit color, scanline tifs
Client request RGB values of light gray areas be within 5 of each other. For example: Red 130, Green 132, Blue 135.
Need batch routine to run on 15,000 images. If it is even possible. Looking for options in CS3 or any other program.

Most automated processes are not able to recognize which objects should be
true gray. For example, PS's auto color or auto levels would make a blue
lake to gray.
I'd recommend a combined manual and batch process. The operator would
check a known gray area on about every 100th image, convert the image to
Lab mode, and define a set of curves that would correct the color cast.
Then use a batch operation to apply that curve to 100 images centered on
that image. This would take 150 manual operations.
If the weather is constant, you may be able to increase the batch size
considerably. By the same token, for changing sun angle, cloud cover or
other situations that affect the color, you may need to increase the number
of manual checks.

Similar Messages

Is it possible to alter a Color's RGB value ?

I'd like the Color references I'm using to stay referring to the same object when I change the color values. So ideally I'd like to change the RGB values of these Colors, since making new Color objects is obviously not what I want.
Neither Color nor ColorSpace have anything to offer, and googling hasn't turned up much.
I have to do it this way, because several classes all have their own reference to the Color, so creating a new Color for one reference won't change them all.
Any suggestions?

Cheers for the blog post Kirill ;o) That's a really neat trick :)
Since every inbuilt Java class I know of uses
getRGB(), this is all that's needed :o)
No worries about the Java classes you don't know of,
or whether anyone else on your project might use
"getRed()" etc? And you've ditched alpha information
too.No-one else is working on my project mate ;o) And despite your sarcasm, you are right - there aren't any worries about Java classes I 'don't know of', since the colours I'm using are only read for rendering; nothing more. Every method I have that affects the colours deal with WebColor, so that's fine. Graphics.setColor(WebColor wc) works fine too, with my 'nasty hack', as you call it. So I'm more than happy, I assure you.
If it was me doing a nasty hack like that I'd at
least override everything so it was a stable nasty
hack instead of an unstable one ;o)Well that's the difference between us then; I don't do work that I know won't be needed :D
I'm just being facetious, because I was slightly offended by your taunting tone, itchy :oP I know you're right, of course. What I've said above is true, but obviously I agree that a stable class that can be used generically is far better than my case-specific code. I'll be changing my class to kilrillg's nifty code right now :o)
Thanks again Kirill.

Why does my cell table not display color but RGB value

Could somebody please suggest me.
What I wanted is to let one collumn of a table display colors, but now they display the RGB values of the color not the colors.
Please suggest me how I should do to get this done.
Thanks.

The renderer displays the toString() value of the Object stored in the table by default. If you want to display something else then you need to use a custom renderer
The Swing tutorial on [url http://java.sun.com/docs/books/tutorial/uiswing/misc/keybinding.html]How to Use Tables explains what a renderer is and has an example that displays a color in a column.

When I open a jpg file in Firefox, it has different RGB values than when I open it in Microsoft Paint or Picture and Fax Viewer. What kind of color management does Firefox apply to jpg files?

In Firefox, the RGB values are 50, 255, and 25. In Paint, they are 81, 171 and 67. These colors look quite different. I suspect Firefox is doing something with the

Does Firefox use the embedded color profile if there is one? How can I tell if there is one in a jpg and what it is?

RGB Color management between Illustrator and Photoshop

Hi,
I have a color management issue when exporting JPGs from Illustrator and opening them in Photoshop:
In Illustrator (file is in RGB mode), I have a logo which has the color RGB 0/0/153 and I export a JPG. When I open the file in Photoshop, the color is RGB 1/0154.
I have activated Adobe CC Color Manegement via Adobe Bridge (option "Europe, Universal 3"), which should produce consistent results in all Adobe applications.
So which is the color that is actually in the file? And what do I have to do to get the color I want (0/0/153) actually exported from Illustrator? I need this color to comply with corporate design specifications of my client.
Since I have to produce a lot of files it is not possible to readjust all colors in Photoshop ...
Thank you!
Michael

First, check to make sure that the RGB working colorspace is the same for both Illustrator and Photoshop.
When exporting the jpeg from Illustrator make sure the 'embed' color profile is selected, and it is the color profile that is required for your client. If this is for web use, then sRGB is your best choice.
When you open the exported image in Photoshop, make sure that the color settings for Photoshop are set to 'Preserve Embedded Profiles'. After you open the image in Photoshop, you can double check by going to Edit > Convert to Profile... The source profile should match the embedded exported profile from Illustrator. If these match, your RGB color values from Illustrator and Photoshop should also match.
If the source profile does not match, cancel out of the 'Convert to Profile" and go to 'Assign Profile". Assign the profile that you embedded when exporting from Illustrator. Now Photoshop should have the same values as Illustrator.

Background Color - RGB Value

Hello,
I have embedded a video in this post. I have a FCP background color RGB Value 102, 151, 202. YOu can see the bad results in the video. The text almost starts out gray, then fades into white - which it should just simply fade in.
If I place the background in Motion - I don't have this issue - but I use Motion for titling.
Keep in mind, this is simply a test project, not the real project i was working with, but I replicated the issue. Any help would be greatly appreciated.
http://web.mac.com/chris.ducasse/mtest/test.mp4

This is probably bug 777312. Call Support for the latest info on this bug and for help getting it fixed.

How to find the RGB Values of a Color for Hyperion

When customizing your Hyperion forms, we come across situations where we need the exact RGB value of a given color. This article explains a simple technique to find the RGB values using MS Paint and the Calculator applications that come as standard applications with your operating system.
Here are the steps to find the exact RGB value of a given color.
1) View your Hyperion form using IE, scroll down until you see the color you want to find the RGB value and press the "Print Screen" button (in your keyboard).
2) Open MS Paint and click Edit -> Paste or simply Ctrl+V. What you saw in the browser will be copied as a new untitled image.
3) Select the Color Picker tool and click on an area that has the color you want to match.
4) Now go to Edit Colors... option and click on the "Define Custom Colors >>" button. The color you picked will be selected on this palette. At the bottom right hand corner you will see the Red, Green and Blue values you need. Note down the R,G,B values (given in decimal).
5) Now we need to find out the hexa-decimal values that correspond to those decimal values. This is where we use the simple Calculator. Open the Calculator application from Program -> Accessories. Switch to the scientific mode by clicking View ->Scientific.
6) By default it will be in the decimal number mode. Enter the R value (238 in this example) and click on the Hex radio button. The corresponding hexa-decimal value (EE in this case) will be shown in the dial.
The selected color in this case has the same value for R, G and B. (In fact, all shades of gray has the same values for R, G and B.) Therefore, the RGB value of the background color that we need is #eeeeee. Repeat step 6 to find out the hex value for the Green and Blue elements, if they are different.
Tip:
If you find it difficult to pick a color, zoom the image by pressing Ctrl+PageDown or using View -> Zoom -> Custom... option.

These tips are to find the RGB color of HFM default row where row is text and text lines in data columns are also visible to business users as Yellow as an input cell. By applying the same RGB color you can apply the same color to your data cells or rows. This post shows how to identify color from any web view-able object.
Regards,
Manaf

How to change the text color of a label by using RGB values without changing the background colour?

xCode interface builder:
When I try to change the color property of a label's text by using the RGB values, the background color also changes to the same value automatically.
in other words:
While setting the RGB values for text colour of labels, the background colour also changes unless we use the sliders.
How to make sure that only the color of text changes and not the background?

You can simply do this.
[labelname setTextColor:[UIColor colorWithRed:38/255.0f green:171/255.0f blue:226/255.0f alpha:1.0f]];

Legalities of color-and why are my RGB values inconsistent?

Hi there,
I have a client who is trying to trademark their logo and the RGB values. I have sent them the files and corresponding RGB values, but when they check the files in their mac Digital Color Meter they come up with different values. On my own computer, the values are consistent in the DCM and Photoshop, although I opened it on another computer and found that while the values were still correct when I open the files in Photoshop, the DCM values were incorrect there too.
Does anybody have any history with this? Should I just tell them to ignore their DCM and that Photoshop is correct, or am I doing something wrong with profiles or something? It wouldn't be such a big deal but for the legal implications behind it...
Thanks for any help!!
Eli

I was referring to "Scene Referred" CCchart Lab reference numbers derived from measurements taken of this chart from a spectrophotometer. You'll note the black patch is at L20 according to X-rite. The white patch is quite easy to attain L96 without clipping during exposure of the CCchart to build the profile from using DNG Profile Editor.
What's not easy to control during exposure is the contrast ratio recorded by the camera. Adjusting the middle slider in Levels or the Contrast slider in ACR will show just how much contrast affects hue and saturation viewed on a display. Reality doesn't behave this way.
Contrast/Luminance ratio's are disregarded or barely adjusted for in the DNG CCchart Wizard to come up with proper hue/saturation levels for each of the 18 color patches. The contrast adjusts required to get all 24 patches to match exactly (especially black at L20) makes the image not look right or follow a normal human visual response or perception.
You can adjust contrast in the image after applying the new profile to get a reasonably correct look but quite a few of the 24 patches go off the charts according to the X-rite reference Lab numbers. The whole reason for going by the Lab numbers in profiling a device like a DSLR in the first place is to maintain consistency image to image by using measured results. As you can see this is not possible to achieve in a photograph except maybe in a controlled studio environment, but it does work when trying to match single spot colors that aren't influenced by the surround effect that affects human perception inherent in a photographed scene. A pleasing photograph is not about accurate numbers.
A spectrophotometer is a static device that only reads and measures color wave lengths from color patches and converts them to Lab numbers. It's not a constantly adjusting device like our eyes which adapts to hue, saturation, color temp and contrast levels in any given scene.
I'm going to post three images of a CCchart exposed under a high noon sun that I used to build two different DNG profiles. The first is using ACR default DNG converted source image and doing a straight dual illuminant table profile according to instructions. They're screenshots that include Apple's DCM to show how the black patch changes to accommodate exact Lab numbers as opposed to achieving a pleasing look. You'll note the more the image is made to "pop" the less accurate the Lab readouts and appearance.

System colors do not give correct RGB values

When using the IMAQ integer to color value function, I get correct RGB values for colors chosen via a color box control - except if the colors are selected from the “system colors”. Is this supposed to happen? The RGB values for the system "White" is: 0, 0, 9.
Attachments:
ScreenShot010.jpg ‏21 KB

That function does look at the most significant byte. Try wiring the system color to a "Split Number" (numerics "Dat manipulation) to split the I32 to two I16 and then again to get four I8s.
You will find that the "other" bytes has a "1".
System colors are special.
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Need to uncheck the box labeled Preserve RGB Numbers in Color Management

I am trying to set up my color settings for dye sub and the guide I was given for my printer settings shows that in Color Management, the box next to Preserve RGB Numbers should be unchecked. However, in my settings, this is grayed out with the box checked so I am unable to change it. Anyone know how to get around this? Thank you so much!!

Well I'm printing from my RICOH printer onto dye sub paper to be transferred onto ceramic ornaments and the color is never consistent. I'm using the Sawgrass Ink Palette in RGB that's recommended with dye sub so I'm wondering if that little box being checked when it's supposed to be unchecked is the issue

How to use color picker or RGB values in the hue-saturation colorize adjustment

I have a monochromatic adornment that I want to match to the color of a logo. I am attempting to use the colorize option of a hue saturation adjustment layer to match color. But I cannot quite get the colors to match. I know the RGB values of the color, but how do these translate into the Hue/Sat/Lightness numbers of the adjustment dialog? I tried using the correlating H/S/B values fro9m the color picker but that did not work.
Any suggestions?

Thanks Zeno. Creating a layer with the color and using the blend mode worked fine. But as I stated in the original post, using the H/S/B (there is no HSL) values from the color picker does not work when you place them into the H/S/L values in the hue-adjustment layer with (or without) the colorize box checked. But your first suggestion worked like a charm. Thank you.

NEF to DNG 6.5 results in different number of unique colors, pixels and RGB values

I took pictures from my old Nikon D40. I converted them with the standard settings from NEF to DNG.
I then used UFRAW under Linux and saw that the pixel size increased from 3039x2040 in NEF to 3040x2040 in the DNG - and that the live view RGB values were about 5% higher for NEF that for DNG.
"FastStone Image Viewer" shows the same increase in pixel size. Additionally, it shows that the DNG has roughly 93,000 unique colors compare to 90,000 for the NEF file.
More pixel, different RGB values, different counted unique colors - what's going on here? This doesn't look like a 1:1 conversion?

Not exactly sure what you're comparing. For raw data you need to be comparing the original mosaic data values (not some converted result, or even partially converted result like demosaiced result). Are you sure that's what you're doing?

How do I get hexadecimal code or rgb values of the color in a selection?

I have a color. I need to know what its hexadecimal code is or what its rgb values are. I cannot find any tool or interface element in Photoshop that discovers the hexadecimal code or rgb values of a color in a selected area.
I have searched in the User Guide on every phrase I can think of, and not one gets a hit.
Any help will be appreciated.
Thanks,
Jeff

Easiest way is to click on the foreground colour which opens the Color Picker dialog box, and changes the cursor to the eye dropper. Now click on the colour. If it is crucial that it uses your selected area, copy the selection to a new layer. I have no idea if you want a point sample, or average of entire selection or what though?

RGB values of current terminal color settings?

The colors displayed for different ANSI escape codes are configurable via .Xdefaults or directly on the command line via other ANSI escapes.
Is there any way to dump the current values from a terminal? For example, given the ANSI escape code "\033[31m", I would like to know the current RGB values used to display it.
Obviously this will depend on the terminal (e.g. urxvt can have different settings from xterm), but I'm hoping that there is some obscure tool to do this.

Coincidentally, I recently wrote a script to do exactly this: query all the color values from a terminal emulator and show them in a nice table. I was planning to make a thread for this, but this thread is perfect. In my opinion, the strategy of querying colors from the terminal itself is superior (when it is supported by the terminal) to mucking around with .Xresources, .Xdefaults, or "xrdb --query", which only work in pretty limited situations. The drawbacks of my approach are: (1) it can be challenging to make the same code work on different terminal emulators, and (2) you have to use it from the terminal you want to query, and not from within a screen or tmux session. (I think there may be partial workarounds for (2), but I haven't implemented them.) I've tested my code on a number of terminals, and the upshot is that xterm and urxvt are supported flawlessly, and VTE-based terminals like gnome-terminal and XFCE's "Terminal" are almost fully supported. (I wasn't able to query the default foreground and background colors, but everything else seems to work.) Most other X terminals don't seem to support this method of querying color values.
Here's an example of what the script produces:
Obviously, that's a heavily formatted table, but I think the code has enough comments that you can take what you need from it. It works under python 3 or python 2.7.
Edit: This version is superseded by the one in post #27, which is structured better. I'm leaving this here since some of the future replies refer to it.
#!/usr/bin/python
This is a Python script to show off your terminal ANSI colors (or more
colors, if your terminal has them). It works on both Python 2.7 and
Python 3.
This script must be run from the terminal whose colors you want to
showcase. Not all terminal types are supported (see below). At the
very minimum, 16-color support is required.
Fully supported terminals:
xterm
urxvt
For these terminals, this script can show a color table with correct RGB
values for each color. It queries the RGB values from the terminal
itself, so it works even if you change the colors after starting the
terminal.
Mostly supported terminals: pretty much all VTE-based terminals. This
includes:
vte
Terminal (XFCE)
gnome-terminal
terminator
tilda
and many more. These are on "mostly" status because I don't know how to
query their foreground and background colors. Everything else works,
though, albeit with noticeable slowness (which may be beyond this
script's control).
Somewhat supported terminals: pretty much all other X-client terminals
I've tried. These include:
konsole (KDE)
terminology (Enlightenment)
Eterm (Enlightenment)
(etc.)
For these terminals, the script can output a color table just fine, but
without RGB values.
Unsupported terminals:
ajaxterm
Linux virtual console (i.e., basic TTY without X-windows)
Warning: do not run this script on the Linux virtual console unless you
want a garbled TTY! That said, you can still type `tput reset<Enter>'
afterward to get back to a usable console. :-) The situation with
ajaxterm is similar, but not as bad.
If a terminal isn't mentioned here, I probably haven't tried it. Attempt
at your own risk!
Note regarding screen/tmux: this script can theoretically be run from a
screen or tmux session, but you will not get any RGB values in the
output (indeed, a screen session can be opened on multiple terminals
simultaneously, so there typically isn't a well defined color value for
a given index). However, it's interesting to observe that screen and
tmux emulate a 256 color terminal independently of the terminal(s)
to which they are attached, which is very apparent if you run the script
with 256-color output on a screen session attached to a terminal with 8-
or 16-color terminfo (or with $TERM set to such).
This code is licensed under the terms of the GNU General Public License:
http://www.gnu.org/licenses/gpl-3.0.html
and with absolutely no warranty. All use is strictly at your own risk.
from sys import stdin, stdout, stderr
import re
import select
import termios
from collections import defaultdict
from argparse import (ArgumentParser, ArgumentError)
# Operating system command
osc = "\033]"
# String terminator
# ("\033\\" is another option, but "\007" seems to be understood by
# more terminals. Terminology, for example, doesn't seem to like
# "\033\\".)
st = "\007"
# Control sequence introducer
csi = "\033["
# ANSI SGR0
reset = csi + 'm'
# Errors that may be raised by rgb_query
num_errors = 0
class InvalidResponseError(Exception):
The terminal's response couldn't be parsed.
def __init__(self, q, r):
global num_errors
num_errors += 1
Exception.__init__(self, "Couldn't parse response " + repr(r) +
" to query " + repr(q))
class NoResponseError(Exception):
The terminal didn't respond, or we were too impatient.
def __init__(self, q):
global num_errors
num_errors += 1
Exception.__init__(self, "Timeout on query " + repr(q))
# Wrappers for xterm & urxvt operating system controls.
# These codes are all common to xterm and urxvt. Their responses aren't
# always in the same format (xterm generally being more consistent), but
# the regular expression used to parse the responses is general enough
# to work for both.
# Note: none of these functions is remotely thread-safe.
def get_fg(timeout):
Get the terminal's foreground (text) color as a 6-digit
hexadecimal string.
return rgb_query([10], timeout)
def get_bg(timeout):
Get the terminal's background color as a 6-digit hexadecimal
string.
return rgb_query([11], timeout)
def get_color(a, timeout):
Get color a as a 6-digit hexadecimal string.
return rgb_query([4, a], timeout)
def test_fg(timeout):
Return True if the terminal responds to the "get foreground" query
within the time limit and False otherwise.
return test_rgb_query([10], timeout)
def test_bg(timeout):
Return True if the terminal responds to the "get background" query
within the time limit and False otherwise.
return test_rgb_query([11], timeout)
def test_color(timeout):
Return True if the terminal responds to the "get color 0" query
within the time limit and False otherwise.
return test_rgb_query([4, 0], timeout)
def test_rgb_query(q, timeout):
Determine if the terminal supports query q.
Arguments: `q' and `timeout' have the same interpretation as in
rgb_query().
Return: True if the terminal gives a valid response within the
time limit and False otherwise.
This function will not raise InvalidResponseError or
NoResponseError, but any other errors raised by rgb_query will
be propagated.
try:
rgb_query(q, timeout)
return True
except (InvalidResponseError, NoResponseError):
return False
# String to use for color values that couldn't be determined
rgb_placeholder = '??????'
# This is what we expect the terminal's response to a query for a color
# to look like. If we didn't care about urxvt, we could get away with a
# simpler implementation here, since xterm and vte seem to give pretty
# consistent and systematic responses. But I actually use urxvt most of
# the time, so....
ndec = "[0-9]+"
nhex = "[0-9a-fA-F]+"
crgb = ("\033\\]({ndec};)+rgba?:" +
"({nhex})/({nhex})/({nhex})(/({nhex}))?").format(**vars())
re_response = re.compile(crgb)
# The problem I'm attempting to work around with this complicated
# implementation is that if you supply a terminal with a query that it
# does not recognize or does not have a good response to, it will simply
# not respond *at all* rather than signaling the error in any way.
# Moreover, there is a large variation in how long terminals take to
# respond to valid queries, so it's difficult to know whether the
# terminal has decided not to respond at all or it needs more time.
# This is why rgb_query has a user-settable timeout.
P = select.poll()
P.register(stdin.fileno(), select.POLLIN)
def flush_input():
Discard any input that can be read at this moment.
repeat = True
while repeat:
evs = P.poll(0)
if len(evs) > 0:
stdin.read()
repeat = True
else:
repeat = False
def rgb_query(q, timeout=-1):
Query a color-valued terminal parameter.
Arguments:
q: The query code as a sequence of nonnegative integers, i.e.,
[q0, q1, ...] if the escape sequence in pseudo-Python is
"\033]{q0};{q1};...;?\007"
timeout: how long to wait for a response. (negative means
wait indefinitely if necessary)
Return: the color value as a 6-digit hexadecimal string.
Errors:
NoResponseError will be raised if the query times out.
InvalidResponseError will be raised if the terminal's
response can't be parsed.
See
http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
("Operating System Controls") to see the various queries
supported by xterm. Urxvt supports some, but not all, of them,
and has a number of its own (see man -s7 urxvt).
Warning: before calling this function, make sure the terminal is
in noncanonical, non-blocking mode.
query = osc + ';'.join([str(k) for k in q]) + ';?' + st
flush_input()
stdout.write(query)
stdout.flush()
# This is addmittedly flawed, since it assumes the entire response
# will appear in one shot. It seems to work in practice, though.
evs = P.poll(timeout)
if len(evs) == 0:
raise NoResponseError(query)
r = stdin.read()
m = re_response.search(r)
if not m:
raise InvalidResponseError(query, r)
# (possibly overkill, since I've never seen anything but 4-digit RGB
# components in responses from terminals, in which case `nd' is 4
# and `u' is 0xffff, and the following can be simplified as well
# (and parse_component can be eliminated))
nd = len(m.group(2))
u = int('f'*nd, 16)
# An "rgba"-type reply (for urxvt) is apparently actually
# rgba:{alpha}/{alpha * red}/{alpha * green}/{alpha * blue}
# I opt to extract the actual RGB values by eliminating alpha. (In
# other words, the alpha value is discarded completely in the
# reported color value, which is a compromise I make in order to get
# an intuitive and compact output.)
if m.group(5):
# There is an alpha component
alpha = float(int(m.group(2), 16))/u
idx = [3, 4, 6]
else:
# There is no alpha component
alpha = 1.0
idx = [2, 3, 4]
c_fmt = '%0' + ('%d' % nd) + 'x'
components = [int(m.group(i), 16) for i in idx]
t = tuple(parse_component(c_fmt % (c/alpha)) for c in components)
return "%02X%02X%02X" % t
def parse_component(s):
Take a string representation of a hexadecimal integer and transorm
the two most significant digits into an actual integer (or double
the string if it has only one character).
n = len(s)
if n == 1:
s += s
elif n > 2:
s = s[:2]
return int(s, 16)
def test_num_colors(timeout):
Attempt to determine the number of colors we are able to query from
the terminal. timeout is measured in milliseconds and has the same
interpretation as in rgb_query. A larger timeout is safer but will
cause this function to take proportionally more time.
if not test_color(timeout):
return 0
a = 0
b = 1
while test_rgb_query([4, b], timeout):
a = b
b += b
while b - a > 1:
c = (a + b)>>1
if test_rgb_query([4, c], timeout):
a = c
else:
b = c
return b
class ColorDisplay(object):
Class for producing a colored display of terminal RGB values.
def __init__(self, timeout=100, color_level=3, do_query=True):
timeout: same interpretation as in rgb_query. A larger timeout
will be used a small number of times to test the
capabilities of the terminal.
color_level: how much color should be in the output. Use 0 to
suppress all color and 3 or greater for maximum coloredness.
do_query: whether to attempt to query RGB values from the
terminal or just use placeholders everywhere
self.timeout=timeout
self.color_level=color_level
# try getting the rgb value for color 0 to decide whether to
# bother trying to query any more colors.
self.do_query = do_query and test_color(self.timeout*5)
def none_factory():
return None
# colors for highlighting
self.hi = defaultdict(none_factory)
self.hi['['] = 10
self.hi[']'] = 10
self.hi['+'] = 9
self.hi['/'] = 9
for c in '0123456789ABCDEF':
self.hi[c] = 12
def show_ansi(self):
Show the 16 ANSI colors (colors 0-15).
color_order = [0, 1, 3, 2, 6, 4, 5, 7]
names = [' Black ', ' Red ', ' Green ', ' Yellow ',
' Blue ', ' Magenta', ' Cyan ', ' White ']
stdout.write(self.fgcolor('15', 3))
for k in range(8):
a = color_order[k]
stdout.write(names[a])
stdout.write('\n')
stdout.write(self.fgcolor(None, 3))
c = None
for k in range(8):
a = color_order[k]
c = self.hiprint(' [%X/%X] ' % (a, 8 + a), c)
stdout.write('\n')
self.show_color_table([0,8], color_order)
def show_color_cube(self, n):
Show the "RGB cube" (xterm colors 16-231 (256-color) or 16-79
(88-color)). The cube has sides of length 6 or 4 (for 256-color
or 88-color, respectively).
base = {256:6, 88:4}[n]
c = None
c = self.hiprint('[ + ] ', c)
for w in range(base):
c = self.hiprint('[%X] ' % w, c)
stdout.write('\n\n' + self.fgcolor(None, 3))
for u in range(base):
for v in range(base):
stdout.write(' '*v)
x = (u*base + v)*base
self.hiprint(' [%02X] ' % (16 + x))
for w in range(base):
self.show_color(x + w + 16)
stdout.write('\n')
stdout.write('\n\n')
def show_grayscale_ramp(self, end):
Show the "grayscale ramp" (xterm colors 232-255 (256-color) or
80-87 (88-color)).
start = {256:232, 88:80}[end]
n = end - start
vals = [self.get_color(a) for a in range(start, end)]
#stdout.write(reset)
c = None
c = self.hiprint('[ ', c)
for v in range(n):
c = self.hiprint('%02X ' % (start + v), c)
c = self.hiprint(']\n', c)
stdout.write('\n ' + self.fgcolor(None, 3))
for v in range(n):
stdout.write(' ' + self.block(start + v, 2))
stdout.write('\n ')
for u in range(3):
for v in range(n):
stdout.write(' ')
stdout.write(self.fgcolor(start + v, 2))
stdout.write(vals[v][2*u : 2*(u + 1)])
stdout.write(self.fgcolor(None, 2))
stdout.write('\n ')
stdout.write('\n')
def show_colors(self, n):
Make a table showing colors 0 through n-1.
self.show_color_table(range(0,n,8), range(8), n, True)
def show_color_table(self, rows, cols, stop=-1, label=False):
Make a color table with all possible color indices of the form
rows[k] + cols[j] that are less than `stop' (if `stop' is not
negative). If label is True, then print row and column labels.
if label:
self.hiprint('[ + ]')
stdout.write(self.fgcolor(None, 3))
for a in cols:
stdout.write(' ' + self.octal(a) + ' ')
stdout.write('\n')
if label:
stdout.write(' ')
stdout.write('\n')
for b in rows:
if label:
stdout.write(self.octal(b) + ' ')
for a in cols:
c = a + b
if stop < 0 or c < stop:
self.show_color(b + a)
else:
stdout.write(' ')
stdout.write('\n')
stdout.write('\n')
def show_color(self, a):
Make a pretty display of color number `a', showing a block of
that color followed by the 6-character hexadecimal code for the
color.
stdout.write(' ' + self.block(a) + ' ')
stdout.write(self.fgcolor(a, 2) + (self.get_color(a)))
stdout.write(self.fgcolor(None, 2))
def hiprint(self, s, last_color=-1):
Print s to stdout, highlighting digits, brackets, etc. if the
color level allows it.
Arguments:
s: the string to print.
last_color: the current terminal foreground color. This
should be `None' if no color is set, or the current
color index, or something else (like a negative integer)
if the color isn't known. (The last option is always
safe and will force this function to do the right
thing.)
Return: the current foreground color, which can be passed as
last_color to the next call if the color isn't changed in
between.
for c in s:
if c == ' ':
color = last_color
else:
color = self.hi[c]
if color != last_color:
stdout.write(self.fgcolor(color, 3))
stdout.write(c)
last_color = color
return last_color
def octal(self, x):
Return a base-8 string for the integer x, highlighted if the
color level allows it.
return self.fgcolor(self.hi['+'], 3) + '0' + \
self.fgcolor(self.hi['0'], 3) + ('%03o' % x)
def block(self, c, n=1):
Return a string that prints as a block of color `c' and size `n'.
return self.bgcolor(c, 1) + ' '*n + self.bgcolor(None, 1)
# Changing the foreground and background colors.
# While the 38;5 and 48;5 SGR codes are less portable than the usual
# 30-37 and 40-47, these codes seem to be fairly widely implemented (on
# X-windows terminals, screen, and tmux) and support the whole color
# range, as opposed to just colors 0-8. They also make it very easy to
# set the background to a given color without needing to mess around
# with bold or reverse video (which are hardly portable themselves).
# This is useful even for the 16 ANSI colors.
def fgcolor(self, a=None, level=-1):
Return a string designed to set the foreground color to `a' when
printed to the terminal. None means default.
if self.color_level >= level:
if a is None:
return csi + '39m'
else:
return csi + '38;5;' + str(a) + 'm'
else:
return ''
def bgcolor(self, a=None, level=-1):
Return a string designed to set the background color to `a' when
printed to the terminal. None means default.
if self.color_level >= level:
if a is None:
return csi + '49m'
else:
return csi + '48;5;' + str(a) + 'm'
else:
return ''
def get_color(self, a):
if self.do_query:
try:
return get_color(a, timeout=self.timeout)
except (InvalidResponseError, NoResponseError):
return rgb_placeholder
else:
return rgb_placeholder
# Command-line arguments
timeout_dft = 200
parser = ArgumentParser(
description="Python script to show off terminal colors.",
epilog="Run this script from the terminal whose colors " +
"you want to showcase. " +
"For a brief synopsis of which terminal types are " +
"supported, see the top of the source code.")
mode_group = parser.add_mutually_exclusive_group()
p_choices = [16, 88, 256]
arg_p = mode_group.add_argument(
'-p', '--pretty',
action='store_true', default=False,
help="show colors 0 through N-1 in a pretty format. " +
("N must belong to %r. " % p_choices) +
"If N > 16, it should be the actual number of colors " +
"supported by the terminal, or the output will almost " +
"certainly not be pretty.")
mode_group.add_argument(
'-f', '--flat',
action='store_true', default=False,
help="show a simple table with colors 0 through N-1. ")
parser.add_argument(
'n', nargs='?', metavar='N',
type=int, default=16,
help="number of colors to show. " +
"Unless you explicitly supply -p/--pretty or -f/--flat, " +
"--pretty is used if possible and --flat is used " +
"otherwise. " +
"N defaults to 16, showing the ANSI colors 0-15. " +
"If N is 0, the script will attempt to determine the " +
"maximum number of colors automatically " +
"(which may be slow).")
parser.add_argument(
'--no-fgbg',
action='store_false', dest='fgbg', default=True,
help="suppress display of foreground/background colors.")
parser.add_argument(
'--no-query',
action='store_false', dest='do_query', default=True,
help="don't try to query any RGB values from the terminal " +
"and just use placeholders.")
parser.add_argument(
'-t', '--timeout', metavar='T',
type=int, default=timeout_dft,
help="how long to wait for the terminal to "
"respond to a query, in milliseconds " +
"[default: {0}]. ".format(timeout_dft) +
"If your output has '?' characters " +
"instead of RGB values " +
"or junk printed after the script runs, " +
"increasing this value may or may not " +
"help, depending on the terminal. " +
"A negative T will behave like infinity.")
parser.add_argument(
'-l', '--level', metavar='L',
type=int, default=3,
help="choose how much color to use in the output. " +
"(0 = no color; 3 = most color [default])")
if __name__ == '__main__':
args = parser.parse_args()
assert not (args.pretty and args.flat)
if args.pretty:
if args.n not in p_choices:
raise ArgumentError(
arg_p,
"N must belong to %r" % p_choices)
tc_save = None
try:
tc_save = termios.tcgetattr(stdout.fileno())
tc = termios.tcgetattr(stdout.fileno())
# Don't echo the terminal's responses
tc[3] &= ~termios.ECHO
# Noncanonical mode (i.e., disable buffering on the terminal
# level)
tc[3] &= ~termios.ICANON
# Make input non-blocking
tc[6][termios.VMIN] = 0
tc[6][termios.VTIME] = 0
termios.tcsetattr(stdout.fileno(), termios.TCSANOW, tc)
if args.n == 0:
args.n = test_num_colors(args.timeout)
# We are guaranteed to have failed some queries now, but
# that isn't meaningful.
num_errors = 0
if not (args.pretty or args.flat):
if args.n in p_choices:
args.pretty = True
else:
args.flat = True
if args.level >= 1:
stdout.write(reset)
if args.fgbg:
if args.do_query:
try:
bg = get_bg(timeout=args.timeout)
except (InvalidResponseError, NoResponseError):
bg = rgb_placeholder
try:
fg = get_fg(timeout=args.timeout)
except (InvalidResponseError, NoResponseError):
fg = rgb_placeholder
else:
bg = rgb_placeholder
fg = rgb_placeholder
stdout.write("\n Background: %s\n" % bg)
stdout.write(" Foreground: %s\n\n" % fg)
C = ColorDisplay(args.timeout, args.level, args.do_query)
if args.pretty:
assert args.n in p_choices
stdout.write('\n ANSI colors:\n\n')
C.show_ansi()
if args.n > 16:
stdout.write('\n RGB cube:\n\n')
C.show_color_cube(args.n)
stdout.write(' Grayscale ramp:\n\n')
C.show_grayscale_ramp(args.n)
else:
C.show_colors(args.n)
if num_errors > 0:
stderr.write("Warning: not all queries succeeded\n" +
"Warning: (output contains " +
"placeholders and may be inaccurate)\n")
finally:
if args.level >= 1:
stdout.write(reset)
flush_input()
if tc_save != None:
termios.tcsetattr(stdout.fileno(),
termios.TCSANOW, tc_save)
Run it as
python showcolors.py -h
to get an overview of the functionality.
TL;DR: you can echo a string like "\033]4;13;?\007" to an xterm, and it will output the RGB value of color #13 to itself in the form "\033]4;13;rgb:rrrr/gggg/bbbb\007", which you can then read and parse. To try it out:
$ echo -en "\033]4;13;?\007"
There are some subtleties if you want this to work on other terminals like urxvt; for that you can experiment yourself or read the code.
Further reading: http://invisible-island.net/xterm/ctlseqs/ctlseqs.html (heading "Operating System Controls").
Xyne, regarding determining the number of colors: I don't know how to do that completely reliably. You can try simply
tput colors
but this relies on the value of $TERM and its terminfo and thus may be unreliable. A kludgy but workable way to do this using the "rgb_query" function in my script is to query color values using binary search to find the highest color value the terminal will allow you to query. The main problem with this is that if you query an invalid color index, then the terminal just won't respond at all, and if you query a valid index, it will respond but after a somewhat unpredictable delay, so it's hard to know for sure which one is the case. Like I said, it's kludgy but workable.
Edit: I went ahead and added that functionality to my script. Try running it as
python showcolors.py 0
or look at the function "test_num_colors".
Last edited by Lux Perpetua (2012-10-22 11:18:21)

Color management: RGB values

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