Re: [Gimp-user] Changing house colour

2004-04-27 Thread Steve Litt
On Sunday 25 April 2004 03:02 am, Ken Walker wrote:
 I was asked the other day if I could change the dark brown trim on our
 house including down spouts and eavestroughs but not the roof  as shown in

 http://qblaw.ca/house.jpg

Ken -- I use the dxm theme for IceWM. It's primarily dark green with subdued 
greens and yellows. Your house photo makes the ideal background for this 
theme.

Thanks

SteveT

Steve Litt
Founder and acting president: GoLUG
http://www.golug.org

___
Gimp-user mailing list
[EMAIL PROTECTED]
http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user


Re: [Gimp-user] Changing house colour

2004-04-26 Thread Sven Neumann
Hi,

David Burren [EMAIL PROTECTED] writes:

 Adjusting the white point will scale all the colours in the image.
 For example if you had green writing on yellow paper, adjusting the
 white point like this would change the green to cyan (and red to
 magenta, but not affect any blue writing).
 Mind you, for Steve's receipts and his use of them, the final result
 in BW might be OK.
 
 Adjusting the white point is a very useful technique for colours
 _within_ an image, but it's a bit flawed as a general method for
 rendering the surrounding paper as white (unless the ink is pure
 black).

Right, unless the ink is pure black, which is very common for scanned
documents. With a scanned document, what you usually want to achieve
is to have black text on white background. Unless the scan is
perfectly adjusted, you usually have dark gray text on light gray
background. Picking the white and black points fixes this very
conveniently. If there are photos on the same page, the photo should
be handled separately from the text anyway. It's best put on a
separate layer and treated independently from the text.


Sven
___
Gimp-user mailing list
[EMAIL PROTECTED]
http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user


Re: [Gimp-user] Changing house colour

2004-04-26 Thread David Neary
Hi Ken,

Ken Walker wrote:
 I was asked the other day if I could change the dark brown trim on our house 
 including down spouts and eavestroughs but not the roof  as shown in
 from dark brown to Montana Tan as shown in

First use something like the freehand selection tool to roughly
select the eaves (that is, if you add in stuff outside, don't
worry about it).

Then copy this selection and paste it as a new layer.

Then use the colormap rotation plug-in (in Filters-Color-Map)
to map the dark brown to a lighter brown.

And if anything outside the eaves unintentionally got its colour
changed, you can use the eraser tool (with a small brush) to get
back to the original colour.

Cheers,
Dave.

-- 
   David Neary,
   Lyon, France
  E-Mail: [EMAIL PROTECTED]
___
Gimp-user mailing list
[EMAIL PROTECTED]
http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user


[Gimp-user] Changing house colour

2004-04-25 Thread Ken Walker
I was asked the other day if I could change the dark brown trim on our house 
including down spouts and eavestroughs but not the roof  as shown in

http://qblaw.ca/house.jpg

from dark brown to Montana Tan as shown in

http://qblaw.ca/paint.jpg

Doors would be Autumn haze.

I thought this would be a great exercise in learning to use The Gimp but I 
have become lost in selection modes, layers, channels and the like reading 
Grokking the Gimp and the regular docs.  I have tried to use google to find 
something appropriate to help me with this, but can't come up with the magic 
search words to get me there.

Could someone point me to some resource that will walk me through this task 
and/or give me a bit of an outline of which tools I should use to get where I 
want to go.

And while you are looking at these images, what do you think of the colour 
choice?  They aren't my choices and I have no idea about these things.



Ken
-- 
Ken Walker
http://lunar.ca
___
Gimp-user mailing list
[EMAIL PROTECTED]
http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user


Re: [Gimp-user] Changing house colour

2004-04-25 Thread Steve Litt
On Sunday 25 April 2004 03:02 am, Ken Walker wrote:
 I was asked the other day if I could change the dark brown trim on our
 house including down spouts and eavestroughs but not the roof  as shown in

 http://qblaw.ca/house.jpg

 from dark brown to Montana Tan as shown in

 http://qblaw.ca/paint.jpg

 Doors would be Autumn haze.

 I thought this would be a great exercise in learning to use The Gimp but I
 have become lost in selection modes, layers, channels and the like reading
 Grokking the Gimp and the regular docs.  I have tried to use google to find
 something appropriate to help me with this, but can't come up with the
 magic search words to get me there.

 Could someone point me to some resource that will walk me through this task
 and/or give me a bit of an outline of which tools I should use to get where
 I want to go.

 And while you are looking at these images, what do you think of the colour
 choice?  They aren't my choices and I have no idea about these things.

Hi Ken,

While you're waiting for an authoritative answer I'll give you what I know. 
I'd use the bezier selection tool to select the trim, eavesdrops and spouts, 
but not the roof, trees, etc. Then I'd Rightclick-select-bycolor, click the 
intersection radio button, use a threshold somewhere in the 10-25 area, and 
click a portion of the drawing, inside the selections, that has one of the 
lighter parts of dark brown. This will select all sorts of stuff. Then I'd 
make the foreground color a lighter shade of montana tan, and 
Rightclick-Edit-fillWithForegroundColor. I'd repeat the same thing for a 
slightly darker part of dark brown, replacing with a slightly darker montana 
tan, and so on til all the dark brown on eaves, spouts and trim are replaced 
by montana tan.

My method will eliminate quite a bit of texture. I'm sure some of the other 
people on the list will come up with ways to replace all the brown at once, 
texture and all, and I'll anxiously await that information. But if worst 
comes to worst, you can do what I just said -- I've done it often.

By the way -- I use select by color a lot when I scan yellow receipts. I use 
select by color to turn the yellow to white, then save it as grayscale and 
save mucho megabytes.

SteveT

Steve Litt
Founder and acting president: GoLUG
http://www.golug.org

___
Gimp-user mailing list
[EMAIL PROTECTED]
http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user


Re: [Gimp-user] Changing house colour

2004-04-25 Thread Sven Neumann
Hi,

Steve Litt [EMAIL PROTECTED] writes:

 While you're waiting for an authoritative answer I'll give you what
 I know.  I'd use the bezier selection tool to select the trim,
 eavesdrops and spouts, but not the roof, trees, etc.

That's a good start. You can then for example use
Filters-Colors-Map-Colormap Rotation to shift the hue of brownish
colors to a different color.

 By the way -- I use select by color a lot when I scan yellow
 receipts. I use select by color to turn the yellow to white, then
 save it as grayscale and save mucho megabytes.

The classic method to make the paper on a scan to appear as white is
to use the Levels tool. Use the white-point color picker and click on
an empty spot of the scan. Or, even better, define the white-point
before doing the actual scan. Most scan software (including XSane)
supports this operation.


Sven
___
Gimp-user mailing list
[EMAIL PROTECTED]
http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user


Re: [Gimp-user] Changing house colour

2004-04-25 Thread David Burren

Sven Neumann [EMAIL PROTECTED] wrote:

 Steve Litt [EMAIL PROTECTED] writes:

  By the way -- I use select by color a lot when I scan yellow
  receipts. I use select by color to turn the yellow to white, then
  save it as grayscale and save mucho megabytes.
 
 The classic method to make the paper on a scan to appear as white is
 to use the Levels tool. Use the white-point color picker and click on
 an empty spot of the scan. Or, even better, define the white-point
 before doing the actual scan. Most scan software (including XSane)
 supports this operation.

That has a quite different effect from what Steve mentioned.

Adjusting the white point will scale all the colours in the image.
For example if you had green writing on yellow paper, adjusting the
white point like this would change the green to cyan (and red to
magenta, but not affect any blue writing).
Mind you, for Steve's receipts and his use of them, the final result
in BW might be OK.

Adjusting the white point is a very useful technique for colours
_within_ an image, but it's a bit flawed as a general method for
rendering the surrounding paper as white (unless the ink is pure
black).

Cheers
__
David
___
Gimp-user mailing list
[EMAIL PROTECTED]
http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user