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Distortion Correction
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| N! Xau 2005-02-25, 6:46 pm |
| Seen the big success of my previous post, I have another lil' question.
After I resize a .jpg with PSP 7, *reducing* its size, is there a simple way
to correct the distortion?
For instance, if I do the same thing with Front Page, I have a button for
this purpose on the image toolbar.
thanks
--
N! Xau - sovrintendente agli antani upgradati
la sede del Movimento Salvaguardia e Tutela Cazzate:
http://ilovemiliofede.altervista.org
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| All Things Mopar 2005-02-25, 6:46 pm |
| N! Xau commented courteously ...
> Seen the big success of my previous post, I have
> another lil' question. After I resize a .jpg with
> PSP 7, *reducing* its size, is there a simple way
> to correct the distortion? For instance, if I do
> the same thing with Front Page, I have a button for
> this purpose on the image toolbar.
I'll be positive this time...
Since I don't use Front Page, I don't know for sure what
you mean by "distortion". Are you talking about JPEG
artifacts damaging your images?
If so, could you provide some details as to the before
and after sizes, etc., including the JPEG compression
factor(s) you're using?
For my personal needs in PSP 8/9, I only rarely go over
JPEG=15, since I've found that artifacts can crop up. If
you're up into the 25-30+ range, you may be inadvertantly
damaging your images. And, since PSP remembers the last-
used setting, you maybe saved at a high compression some
time back and didn't re-adjust.
Just some initial thoughts...
--
ATM, aka Jerry
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| Kris Zaklika 2005-02-25, 6:46 pm |
| "N! Xau" wrote:
>
> Seen the big success of my previous post, I have another lil' question.
> After I resize a .jpg with PSP 7, *reducing* its size, is there a simple way
> to correct the distortion?
I'm not sure what distortion you are referring to. If you
mean lens distortion, this correction is in PSP 8 onwards.
If you mean that the image was resized unequally in the
horizontal and vertical dimensions, then resize using the
Maintain Aspect Ratio option. If you mean that you get
JPEG artifacts, then use a lower compression level or use
the JPEG Artifact Removal filter. If you mean that the
smaller image has less detail that the larger original,
then this is unavoidable because you have fewer pixels and
the pixel is the basic information-carrying unit of an
image. You can create the illusion of more detail by
running the Sharpen filter after resizing or, if you are
resizing by a large amount, resizing in several steps
(possibly sharpening in between steps). If you mean
something else, you'll have to explain what that might be.
> For instance, if I do the same thing with Front Page, I have a button for
> this purpose on the image toolbar.
I've never used FP and never will so I'm afraid I don't
know what that means.
> thanks
>
> --
> N! Xau - sovrintendente agli antani upgradati
>
> la sede del Movimento Salvaguardia e Tutela Cazzate:
> http://ilovemiliofede.altervista.org
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"N! Xau" <nxauNO_SPAM_PLEASE@hotmail.com> wrote in message
news:388vqiF5hk0e5U1@individual.net...
> Seen the big success of my previous post, I have another lil' question.
> After I resize a .jpg with PSP 7, *reducing* its size, is there a simple
> way
> to correct the distortion?
> For instance, if I do the same thing with Front Page, I have a button for
> this purpose on the image toolbar.
>
>
> thanks
>
> --
> N! Xau - sovrintendente agli antani upgradati
>
> la sede del Movimento Salvaguardia e Tutela Cazzate:
> http://ilovemiliofede.altervista.org
>
You must keep the same ratio if you are to avoid distortion. Put a check in
the maintain aspect ratio box in the resize dialog.Then trim of an edge or
top/bottom to get you required width height. The distortion tool will resize
as in frontpage but you will have to keep an eye on the status bar for width
or height, and again trim if you need to get a different aspect ratio
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| Kris Zaklika <Kris.Zaklika@corel.com> Kris.Zaklika@corel.com 25 Feb 2005
wrote in news:421F5C4E.169EDE09@corel.com:
> "N! Xau" wrote:
>
> I'm not sure what distortion you are referring to. If you
> mean lens distortion, this correction is in PSP 8 onwards.
Kris, read the article. When he resizes, PSP distorts the image. Nothing in
PSP-8 isn't going to correct that.
:-)
Uni
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| N! Xau 2005-02-26, 6:38 pm |
|
"Uni" <no.email@no.email.invalid> ha scritto nel messaggio
>
> Kris, read the article. When he resizes, PSP distorts the image. Nothing
in
> PSP-8 isn't going to correct that.
Ok, I may be confused, not an expert nor a Corel employee or a professional
web designer.
In Front Page, there's a button for "resampling". It's very useful when you
have to create thumbnails. Infact, resizing a .jpg to 25%, for example, the
thumbnail appears much better after you use this tool.
I wonder if the resizing method in PSP *already* has this feature in it, or
if there's something you can do to improve the quality of resized pics.
About resizing ratio, and preserving that aspect, I'm not such a newbie.
thanks
--
N! Xau - sovrintendente agli antani upgradati
la sede del Movimento Salvaguardia e Tutela Cazzate:
http://ilovemiliofede.altervista.org
| |
| All Things Mopar 2005-02-26, 6:38 pm |
| N! Xau commented courteously ...
> In Front Page, there's a button for "resampling". It's
> very useful when you have to create thumbnails. In
> fact, resizing a .jpg to 25%, for example, the
> thumbnail appears much better after you use this tool.
>
> I wonder if the resizing method in PSP *already* has
> this feature in it, or if there's something you can do
> to improve the quality of resized pics.
N!, again, I don't have FP, but I've found way back with
the old Aldus PhotoStyler, then Adobe PhotoShop 5.0 LE
(my one and only PS product), then, PSP 7/8/9, that I
really cannot reduce any image to 25% of its former size
without doing at least some damage to it.
You've said you aren't a newbie, and I believe that. So,
I expect you know that once a JPEG is brought into either
FP or PSP, it is just a mass of pixels without real
format (except, of course, things that are carried along
with the format along with the pixels). And, I expect
that you also know that PSP can use "resampling" instead
of "pixel resizing" which will definitely destroy an
image with a large up- or down-size (I believe that you
already said you have it set to "smart size").
I've found through personal experience that Kris
Zaklika's recommendation to resize down in steps, with
intermediate mild sharpening, does improve the quality of
my thumbnails dramatically.
If you've not tried that, give it a go and see if that
helps you. If you have and not seen the improved
appearance of FP's method, then I'll just STFU.
--
ATM, aka Jerry
| |
| Don Stauffer in Minneapolis 2005-02-26, 6:38 pm |
| N! Xau wrote:
> Seen the big success of my previous post, I have another lil' question.
> After I resize a .jpg with PSP 7, *reducing* its size, is there a simple way
> to correct the distortion?
> For instance, if I do the same thing with Front Page, I have a button for
> this purpose on the image toolbar.
>
>
> thanks
>
We need to clarify what you mean as distortion. Distortion is a lack of
geometric fidelity in the image. Straight lines go curved, etc. The
most common forms of distortion are barrel distortion (common in
super-wide angle lenses, and pincushion distortion.
JPEG compression should NOT cause such distortion, nor shold reducing
the number of pixels.
If you mean loss of resolution, and the taking on of a 'pixelated' form,
then that is hard to overcome whether the original file is jpeg or any
other format. The basic resolution of the image is proportional to the
number of pixels it contains.
One can reduce the PHYSICAL size of an image without reducing the number
of pixels. But reducing the number of pixels always extracts a price in
image quality. Some software has resizing algorithms that reduce
somewhat the loss in quality, but only within narrow limits.
| |
| Kris Zaklika 2005-02-26, 6:38 pm |
| "N! Xau" wrote:
>
> "Uni" <no.email@no.email.invalid> ha scritto nel messaggio
>
> in
>
> Ok, I may be confused, not an expert nor a Corel employee or a professional
> web designer.
Nor is the poster, Uni, to whom you are replying.
> In Front Page, there's a button for "resampling". It's very useful when you
> have to create thumbnails. Infact, resizing a .jpg to 25%, for example, the
> thumbnail appears much better after you use this tool.
>
> I wonder if the resizing method in PSP *already* has this feature in it, or
> if there's something you can do to improve the quality of resized pics.
One difficulty I have in answering your question is that when
I resize images in PSP 7 they are not "distorted" as you say.
Clearly, you are doing something different than I but I can't
say what that is. This is because you haven't said what is
the original size of the image (in pixels) and what is the
final size, and exactly what settings you are using in the
Image > Resize dialog. For all I know you may instead be using
the Deform tool. I recommend using the Image > Resize dialog.
When resizing for web use you should ignore the Actual/Print
Size section of the dialog and set the new size of the image
in the Pixel Size or Percentage of Original sections. Make
sure the Resize Type is set to Smart Size and the Maintain
Aspect Ratio checkbox is checked. If you resize an image to
25% percent of the original size in this way, there should
be no problems with the quality of the image. You may want
to do Effects > Sharpen > Sharpen on the resized image but
the optimum sharpness is a matter of taste. If I had to guess
about the reason for your problems it is because you have
the Resize Type set to something like Pixel Resize. When
resizing by a very large amount, much smaller than 25%, you
can get better results by resizing in several steps as
I indicated before, optionally sharpening after each step.
There is one other consideration to keep in mind when your
original image contains fine scale periodic patterns such
as closely spaced fence posts, distant bricks, tiles,
clapboards and the like. When resized smaller, such content
is subject to aliasing. Aliasing can be eliminated by reducing
the high spatial frequency components in the image before
resizing. Do this by very slight blurring of the image before
resizing, for instance by means of Gaussian Blur at a setting
of 1. Note that this step is *not* required for normal images,
only for those with very specific content. You will know
when to blur because if you don't you will see banding in
the periodic pattern after resizing. This is the best
advice I can give you when I'm guessing about what you are
doing. If you want to explain more about your problem I
might be able to give more help. As I said at the outset,
there is no reason at all why images resized correctly in
PSP 7 should be distorted in any way.
> About resizing ratio, and preserving that aspect, I'm not such a newbie.
>
> thanks
>
> --
> N! Xau - sovrintendente agli antani upgradati
>
> la sede del Movimento Salvaguardia e Tutela Cazzate:
> http://ilovemiliofede.altervista.org
| |
|
| N! Xau wrote:
> "Uni" <no.email@no.email.invalid> ha scritto nel messaggio
>
Nothing[color=darkred]
> in
>
> Ok, I may be confused, not an expert nor a Corel employee or a
professional
> web designer.
>
> In Front Page, there's a button for "resampling". It's very useful
when you
> have to create thumbnails. Infact, resizing a .jpg to 25%, for
example, the
> thumbnail appears much better after you use this tool.
>
> I wonder if the resizing method in PSP *already* has this feature in
it, or
> if there's something you can do to improve the quality of resized
pics.
You might be referring to the need for sharpening. If you are shrinking
a sharp image down to 25% you would normally need to sharpen somewhat
afterwards. Experiment with PSP's built-in tools for this. Since PSP is
an image processing application you will be able to duplicate or
improve on anything FP can do in this area.
>
> About resizing ratio, and preserving that aspect, I'm not such a
newbie.
>
> thanks
>
> --
> N! Xau - sovrintendente agli antani upgradati
>
> la sede del Movimento Salvaguardia e Tutela Cazzate:
> http://ilovemiliofede.altervista.org
| |
|
| "N! Xau" <nxauNO_SPAM_PLEASE@hotmail.com> nxauNO_SPAM_PLEASE@hotmail.com 26
Feb 2005 wrote in news:38bb7tF5ko615U1@individual.net:
>
> "Uni" <no.email@no.email.invalid> ha scritto nel messaggio
>
> in
>
> Ok, I may be confused, not an expert nor a Corel employee or a professional
> web designer.
>
> In Front Page, there's a button for "resampling". It's very useful when you
> have to create thumbnails. Infact, resizing a .jpg to 25%, for example, the
> thumbnail appears much better after you use this tool.
>
> I wonder if the resizing method in PSP *already* has this feature in it, or
> if there's something you can do to improve the quality of resized pics.
>
> About resizing ratio, and preserving that aspect, I'm not such a newbie.
I know what you are trying to do. All I said was later versions of PSP will
improve the image any better than the version you currently have, If FP works
best, stay with it.
Uni
>
> thanks
>
| |
|
| Kris Zaklika <Kris.Zaklika@corel.com> Kris.Zaklika@corel.com 26 Feb 2005
wrote in news:4220A3E4.E255A5A8@corel.com:
> "N! Xau" wrote:
>
> Nor is the poster, Uni, to whom you are replying.
Excuse me, but I did work at Corel, but then I woke up from the nightmare.
:-)
You should have followed in Mr. Fromm's steps, Kris, rather than sail along
to wherever the Voit winds blow you.
:-)
Uni
[color=darkred]
>
>
> One difficulty I have in answering your question is that when
> I resize images in PSP 7 they are not "distorted" as you say.
> Clearly, you are doing something different than I but I can't
> say what that is. This is because you haven't said what is
> the original size of the image (in pixels) and what is the
> final size, and exactly what settings you are using in the
> Image > Resize dialog. For all I know you may instead be using
> the Deform tool. I recommend using the Image > Resize dialog.
> When resizing for web use you should ignore the Actual/Print
> Size section of the dialog and set the new size of the image
> in the Pixel Size or Percentage of Original sections. Make
> sure the Resize Type is set to Smart Size and the Maintain
> Aspect Ratio checkbox is checked. If you resize an image to
> 25% percent of the original size in this way, there should
> be no problems with the quality of the image. You may want
> to do Effects > Sharpen > Sharpen on the resized image but
> the optimum sharpness is a matter of taste. If I had to guess
> about the reason for your problems it is because you have
> the Resize Type set to something like Pixel Resize. When
> resizing by a very large amount, much smaller than 25%, you
> can get better results by resizing in several steps as
> I indicated before, optionally sharpening after each step.
> There is one other consideration to keep in mind when your
> original image contains fine scale periodic patterns such
> as closely spaced fence posts, distant bricks, tiles,
> clapboards and the like. When resized smaller, such content
> is subject to aliasing. Aliasing can be eliminated by reducing
> the high spatial frequency components in the image before
> resizing. Do this by very slight blurring of the image before
> resizing, for instance by means of Gaussian Blur at a setting
> of 1. Note that this step is *not* required for normal images,
> only for those with very specific content. You will know
> when to blur because if you don't you will see banding in
> the periodic pattern after resizing. This is the best
> advice I can give you when I'm guessing about what you are
> doing. If you want to explain more about your problem I
> might be able to give more help. As I said at the outset,
> there is no reason at all why images resized correctly in
> PSP 7 should be distorted in any way.
>
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