PainShop Pro Graphics - Re: Painted purple flower

Author

Re: Painted purple flower - P1040168a_painted.jpg -

Spandex Rutabaga

2006-07-10, 7:43 pm

Gene Healy wrote:

> Problem I have with Image --> Border or Image --> Canvas Size is I
> lose the 8x10 image size that I want.
>
> Which is why I found it 'better' to add a layer and reduce the image
> to a percentage of its original size. But the drawback on this as
> Barbara pointed out is the top & bottom borders tend to be narrower
> than the sides.

If the image starts at the desired aspect ratio Add Borders
cannot work. Assume B is the width of the border and H and W
are respectively the initial height and width of the image.

Original Aspect Ratio = H / W
New Aspect Ratio = (H + 2 x B) / (W + 2 x B)

In other words, on the assumption of a uniform border width the
aspect ratio is not preserved.

The new layer plus percentage resize method cannot work either.
Assume the image is resized smaller by a fraction F.

New width, w = F x W
New height, h = F x H
Side border = 0.5 x (H - h) = 0.5 x H x (1 - F)
Top/bottom border = 0.5 x (W - w) = 0.5 x W x (1 -F)

The two borders can't be equal except in the special case of a
square when H = W.

> I've gotten around this by Select all, Modify --> Contract.

This works because it forces the border to be uniform all the
way around. However, this is done by allowing the aspect ratio
inside the contracted selection to be different from the original
one. See attached.

> Once the
> marching ants align with the sides of the image, I invert the
> selection and delete. This results in an overall image that is still
> 8x10 inches with the white borders all the same pixel width.

Barbara J Bradley

2006-07-10, 7:43 pm

"Spandex Rutabaga" <SpRu@agabatur.xednaps> wrote in message
news:44A89A64.A0AD5A63@agabatur.xednaps...
> Gene Healy wrote:
>
>
> If the image starts at the desired aspect ratio Add Borders
> cannot work. Assume B is the width of the border and H and W
> are respectively the initial height and width of the image.
>
> Original Aspect Ratio = H / W
> New Aspect Ratio = (H + 2 x B) / (W + 2 x B)
>
> In other words, on the assumption of a uniform border width the
> aspect ratio is not preserved.

That is why it is better to use Selections>All,
Selections>Modify>Select Selection Borders and use "inside." This
works only if the image is not cropped too tightly to accommodate the
border inside the image.
Barb

[color=darkred]
>
> The new layer plus percentage resize method cannot work either.
> Assume the image is resized smaller by a fraction F.
>
> New width, w = F x W
> New height, h = F x H
> Side border = 0.5 x (H - h) = 0.5 x H x (1 - F)
> Top/bottom border = 0.5 x (W - w) = 0.5 x W x (1 -F)
>
> The two borders can't be equal except in the special case of a
> square when H = W.
>
>
> This works because it forces the border to be uniform all the
> way around. However, this is done by allowing the aspect ratio
> inside the contracted selection to be different from the original
> one. See attached.
>

Spandex Rutabaga

2006-07-10, 7:43 pm

Barbara J Bradley wrote:
>
> "Spandex Rutabaga" <SpRu@agabatur.xednaps> wrote in message
> news:44A89A64.A0AD5A63@agabatur.xednaps...
>
> That is why it is better to use Selections>All,
> Selections>Modify>Select Selection Borders and use "inside." This
> works only if the image is not cropped too tightly to accommodate the
> border inside the image.

Selections > Modify > Select Selections Borders in Inside mode is
equivalent to Gene's Contract followed by invert - with two
exceptions. First, the latter is somewhat faster in terms of
calculation time. Second, the two produce different results when
you start with a feathered selection. Take a look at the attached.

Note that I am not saying anything negative about your suggestion.
I'm just pointing out some differences that aren't apparent at
first sight. During my experimenting to create the image I posted
I came to the conclusion that the Inside part of Select Selection
Borders does a Contract followed by subtracting the contracted
selection from the original one. The Outside part is done with
Expand followed by subtracting the original selection from the
expanded one. (The selection corners are rounded in this case
just as Expand does.) The Both option does both of those things
and adds the results together for the final result. If that is not
how the filter behaves at least you can predict the results of
Select Selection Borders on this basis. Then it is the subtraction
step that causes the difference between Contract/Invert and
Select Selection Borders/Inside.
is how the filter

> Barb
[color=darkred]

Barbara J Bradley

2006-07-10, 7:43 pm

underprocessable

Spandex Rutabaga

2006-07-10, 7:43 pm

Barbara J Bradley wrote:

> I never use this for borders with feather so don't have that
> problem.

Nor did I expect you to have any. Just think of my post as
piggybacking onto a thread to explain some things that might
not have been apparent about various items that were being
discussed. More general knowledge than "you have to make a
frame like this".

> I use "inside" and build the matte and frame from the inside
> out. With this method, there is no constraint if the image contains
> more than a background layer.

Yes, this is a handy approach. I find the Canvas Size command,
which comes into play with multiple layers, to be astonishingly
clunky and inconvenient.

> In my example, the first border selected was 30 pixels (inside)
> with anti alias on and flood filled with black. The other borders
> selected with no anti alias and the image remains 700 x 700 pixels.
> This looks okay to me . . are there problems?

No there are no problems. I told you at the outset "that I am not
saying anything negative about your suggestion" :)

Barbara J Bradley

2006-07-10, 7:43 pm

"Spandex Rutabaga" <SpRu@agabatur.xednaps> wrote in message
news:44A978B3.F92E19DF@agabatur.xednaps...
>
> Barbara J Bradley wrote:
>
>
> Nor did I expect you to have any. Just think of my post as
> piggybacking onto a thread to explain some things that might
> not have been apparent about various items that were being
> discussed. More general knowledge than "you have to make a
> frame like this".
>
>
> Yes, this is a handy approach. I find the Canvas Size command,
> which comes into play with multiple layers, to be astonishingly
> clunky and inconvenient.
>
>
> No there are no problems. I told you at the outset "that I am not
> saying anything negative about your suggestion" :)

I read that (nothing negative) but, with so much said about all
the different approaches, I wasn't sure. :) Double check everything
when I'm not sure. You threw a curve when you mentioned feather.
Thanks for the confirmation.
Barb

Gene Healy

2006-07-10, 7:43 pm

On Sun, 02 Jul 2006 23:17:40 -0500, Spandex Rutabaga
<SpRu@agabatur.xednaps> wrote:

>Gene Healy wrote:
>
>
>If the image starts at the desired aspect ratio Add Borders
>cannot work. Assume B is the width of the border and H and W
>are respectively the initial height and width of the image.
>
>Original Aspect Ratio = H / W
>New Aspect Ratio = (H + 2 x B) / (W + 2 x B)
>
>In other words, on the assumption of a uniform border width the
>aspect ratio is not preserved.
>
>The new layer plus percentage resize method cannot work either.
>Assume the image is resized smaller by a fraction F.
>
>New width, w = F x W
>New height, h = F x H
>Side border = 0.5 x (H - h) = 0.5 x H x (1 - F)
>Top/bottom border = 0.5 x (W - w) = 0.5 x W x (1 -F)
>
>The two borders can't be equal except in the special case of a
>square when H = W.
>
>
>This works because it forces the border to be uniform all the
>way around. However, this is done by allowing the aspect ratio
>inside the contracted selection to be different from the original
>one. See attached.

Lots of good numbers there. Sheesh, talk about having to drag out the
schooling from way back. <grin>

If I've read, digested and understood everything, you are saying it is
not possible to add borders of equal size and maintain the same aspect
ratio of both the image and the border (i.e. either one or the other
but not both.)

I've been checking out frames that come with matting. 11x14 frames
(1.27 aspect ratio) state they can display 8x10 pictures (1.25 aspect
ratio) so what they are doing is the same as what I do with Select All
--> Modify --> Contract?

Appreciate your comments as always, Spandy.

Regards,

-- Gene
=========================================
Comments, critiques, and suggestions are always
welcomed and encouraged.
---------------------------------------
All post processing done in Paintshop Pro v9.01
=========================================
My photo galleries are at http://ghealy.smugmug.com
=========================================

Spandex Rutabaga

2006-07-10, 7:43 pm

Gene Healy wrote:

> If I've read, digested and understood everything, you are saying it is
> not possible to add borders of equal size and maintain the same aspect
> ratio of both the image and the border (i.e. either one or the other
> but not both.)

Yep.

> I've been checking out frames that come with matting. 11x14 frames
> (1.27 aspect ratio) state they can display 8x10 pictures (1.25 aspect
> ratio) so what they are doing is the same as what I do with Select All
> --> Modify --> Contract?

Or Barb does with Select Selection Borders. The bigger the frame
and image and the smaller the border the less the aspect ratio is
affected. To take the previous example where:
New Aspect Ratio = (H + 2 x B) / (W + 2 x B)
If H and B both tend to very large numbers and B tends to zero
the expression tends to the limit H / W, which was the original
aspect ratio. In the your frame example the error is 2 parts
in 125 or less than 2%. It's a difference that's too small to
see and so a difference that makes no difference. (You will have
noticed that in my example I did just the opposite picking a very
fat border relative to the image size to exacerbate the effect on
aspect ratio so as to make it easier to see and understand.)

Gene Healy

2006-07-10, 7:44 pm

On Mon, 03 Jul 2006 23:41:23 -0500, Spandex Rutabaga
<SpRu@agabatur.xednaps> wrote:

>Or Barb does with Select Selection Borders. The bigger the frame
>and image and the smaller the border the less the aspect ratio is
>affected. To take the previous example where:
> New Aspect Ratio = (H + 2 x B) / (W + 2 x B)
>If H and B both tend to very large numbers and B tends to zero
>the expression tends to the limit H / W, which was the original
>aspect ratio. In the your frame example the error is 2 parts
>in 125 or less than 2%. It's a difference that's too small to
>see and so a difference that makes no difference. (You will have
>noticed that in my example I did just the opposite picking a very
>fat border relative to the image size to exacerbate the effect on
>aspect ratio so as to make it easier to see and understand.)

Again, thanks for the aditional data.

Regards,

-- Gene
=========================================
Comments, critiques, and suggestions are always
welcomed and encouraged.
---------------------------------------
All post processing done in Paintshop Pro v9.01
=========================================
My photo galleries are at http://ghealy.smugmug.com
=========================================