I have PSP8.
I often want to change the "background" colour that an antialiased or
feathered image has been created on.
So ideally it seems to me that I am wanting to change not only the colour of
the background proper, but also the "transition" colours in the
anti-aliasing/feathering boundary area.
Is there a simple method for doing this?
If not, does PSP9 have anything new to offer in this regard?

TIA
Brian Tozer

KiwiBrian wrote:
> I have PSP8.
> I often want to change the "background" colour that an
> antialiased or feathered image has been created on. So ideally it
> seems to me that I am wanting to change not only the colour of
> the background proper, but also the "transition" colours in the
> anti-aliasing/feathering boundary area. Is there a simple method
> for doing this? If not, does PSP9 have anything new to offer in
> this regard?

The Background Eraser was made for this. Depending on the image, you
might also find Selections > Modify > Select Color Range useful.
Both are in v8 and v9.
--
Fred Hiltz,  fhiltz at yahoo dot com

> KiwiBrian wrote: 
ideally it 
of 
the 
method 
in 

Be sure the image is on a "layer" layer instead of a
"Background" layer, before you make your selection.  This way,
your anti-aliased or feathered portion of the edge, is no
specific color at all.  It's just partially transparent instead.
Making it far easier to now place onto any new backgrounds, and
blend right in.

Porter

"Porter"  wrote 
 
> ideally it 
> of 
> the 
> method 
> in 

> Be sure the image is on a "layer" layer instead of a
> "Background" layer, before you make your selection.  This way,
> your anti-aliased or feathered portion of the edge, is no
> specific color at all.  It's just partially transparent instead.
> Making it far easier to now place onto any new backgrounds, and
> blend right in.

Most interesting.
I had assumed that the 'anti-alias' or 'feathering" pixels would just be
normal colours, intermediate between the object and background colours.
As the purpose of the exercise is to modify graphics for web use I am not
sure of the implications of what you are saying in my situation.
I will do some experimenting.
Thanks for the advice Porter.

Brian Tozer

KiwiBrian wrote:
> "Porter"  wrote
> 
>
> Most interesting.
> I had assumed that the 'anti-alias' or 'feathering" pixels would
> just be normal colours, intermediate between the object and
> background colours. As the purpose of the exercise is to modify
> graphics for web use I am not sure of the implications of what
> you are saying in my situation.

Those pixels are indeed intermediate. You can see the implication of
Porter's advice with a simple example. Imagine a green background
with a red, feathered object on it. The feathered pixels are a
mixture of green and red.

To put the object on, say, a blue background, you could erase the
green background, but that would leave a somewhat-green edge around
the red. Instead, you need to erase the green background completely
and erase just the "greenness" from the edges. The Background Eraser
does just that, leaving pure green purely transparent and part-green
colored red with partial transparency. The blue background will show
through at the edges, just as the green background did in the
original. HTH
--
Fred Hiltz,  fhiltz at yahoo dot com

Wasn't it KiwiBrian who wrote:
>
>"Porter"  wrote
> 
>
>Most interesting.
>I had assumed that the 'anti-alias' or 'feathering" pixels would just be
>normal colours, intermediate between the object and background colours.
>As the purpose of the exercise is to modify graphics for web use I am not
>sure of the implications of what you are saying in my situation.
>I will do some experimenting.
>Thanks for the advice Porter.

The world's most popular web browser doesn't yet support partial
transparency, so when you actually come to put your image on the web
your assumption would be true. So what you do is to keep a partially
transparent master copy of your image layer and paste that over the
different backgrounds to create different non-partially-transparent
instances of the image to use on the web.

--
Mike Williams
Gentleman of Leisure

"Mike Williams" wrote

> The world's most popular web browser doesn't yet support partial
> transparency, so when you actually come to put your image on the web
> your assumption would be true. So what you do is to keep a partially
> transparent master copy of your image layer and paste that over the
> different backgrounds to create different non-partially-transparent
> instances of the image to use on the web.

I appreciate all of the replies that I have received so far on this subject.
I am wondering if I might have caused some confusion by use of the word
"background" originally, even tho I had it in quotes.
I am very interested in pursuing this subject further as a learning exercise
on the principles involved so will give a totally specific example.
I know that in the example it would be easier to create a new object from
scratch but then I would not learn what I want to better understand.
I have a jpg or gif graphic which is used on the web to create the effect of
a 'rounded corner with a border' on a corner of a rectangle "box" which
surrounds some text..
So it has 3 main colours, e.g. red inside, black curved segment of the
border, green outside. It is nicely feathered, so there are intermediate
coloured pixels on both sides of the black "border".
For the exercise I wish to change the inner red to blue, the black curved
border segment to orange, and the outer green to mauve, and finish up with
it being nicely feathered. Of course there are three others to do to
complete the job but we only need to consider one.
If the answers so far deal with this situation I will study them after
confirmation, but I am wondering if I may have inadvertantly created a wrong
impression of my query.

Thanks
Brian Tozer

Mike Williams wrote:
>
> The world's most popular web browser doesn't yet support partial
> transparency, so when you actually come to put your image on the web
> your assumption would be true. So what you do is to keep a partially
> transparent master copy of your image layer and paste that over the
> different backgrounds to create different non-partially-transparent
> instances of the image to use on the web.

Actually, there is a workaround to get IE to support PNG transparency:

http://www.nrkn.com/alpha/

Wasn't it KiwiBrian who wrote:
>"Mike Williams" wrote
> 
>
>I appreciate all of the replies that I have received so far on this subject
.
>I am wondering if I might have caused some confusion by use of the word
>"background" originally, even tho I had it in quotes.
>I am very interested in pursuing this subject further as a learning exercis
e
>on the principles involved so will give a totally specific example.
>I know that in the example it would be easier to create a new object from
>scratch but then I would not learn what I want to better understand.
>I have a jpg or gif graphic which is used on the web to create the effect o
f
>a 'rounded corner with a border' on a corner of a rectangle "box" which
>surrounds some text..
>So it has 3 main colours, e.g. red inside, black curved segment of the
>border, green outside. It is nicely feathered, so there are intermediate
>coloured pixels on both sides of the black "border".
>For the exercise I wish to change the inner red to blue, the black curved
>border segment to orange, and the outer green to mauve, and finish up with
>it being nicely feathered. Of course there are three others to do to
>complete the job but we only need to consider one.
>If the answers so far deal with this situation I will study them after
>confirmation, but I am wondering if I may have inadvertantly created a wron
g
>impression of my query.

I find that things like background eraser, hue map and colour replacer
tend to destroy the nice feathered effect and leave some ugly sharp
edges.

I guess there's an easier way than this, but what I ended up doing was:-

Image => Split Channel => CMYK
Discard the Cyan, Magenta and Yellow images
Adjust the brightness and contrast on the "Black" image so that the
range goes from pure black to pure white, you might use
Adjust => Brightness & Contrast => Brightness/Contrast
or Adjust => Brightness & Contrast => Curves
Create a new image and fill it with your new orange colour
Use the adjusted "Black" image as a mask
Layers => New Mask Layer => From Image
specifying "Source Luminance"

This gives you the feathered orange border on a transparent background.
You can then simplify the layering by doing a Layer Ungroup and Layer
Merge Down (don't use Merge All or you'll lose the transparency)

Add a new raster layer underneath and paint in the blue and mauve.

If your starting colours are different, then you might need to split the
channel to HSL or RGB, or choose a different separated channel.
Once you've got a good mask, save it for future use in case you need to
paste the same border shape over other background colours.

--
Mike Williams
Gentleman of Leisure

"Mike Williams" <nospam@econym.demon.co.uk> wrote in message
news:$IJsNHAM$PVBFwBG@econym.demon.co.uk...
> Wasn't it KiwiBrian who wrote: 
>
> I find that things like background eraser, hue map and colour replacer
> tend to destroy the nice feathered effect and leave some ugly sharp
> edges.
>
> I guess there's an easier way than this, but what I ended up doing was:-
>
>  Image => Split Channel => CMYK
>  Discard the Cyan, Magenta and Yellow images
>  Adjust the brightness and contrast on the "Black" image so that the
>     range goes from pure black to pure white, you might use
>        Adjust => Brightness & Contrast => Brightness/Contrast
>     or Adjust => Brightness & Contrast => Curves
>  Create a new image and fill it with your new orange colour
>  Use the adjusted "Black" image as a mask
>     Layers => New Mask Layer => From Image
>     specifying "Source Luminance"
>
> This gives you the feathered orange border on a transparent background.
> You can then simplify the layering by doing a Layer Ungroup and Layer
> Merge Down (don't use Merge All or you'll lose the transparency)
>
> Add a new raster layer underneath and paint in the blue and mauve.
>
> If your starting colours are different, then you might need to split the
> channel to HSL or RGB, or choose a different separated channel.
> Once you've got a good mask, save it for future use in case you need to
> paste the same border shape over other background colours.

Thanks very much for all your trouble Mike.
I am off to study and hopefully learn from your efforts and expertise.

Brian Tozer