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reducing image size for web pages?

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Anonymous
July 8, 2005 12:30:13 AM

Archived from groups: rec.photo.digital (More info?)

what's the best way to reduce image size but retain sharpness? I
sometimes sharpen a little before reducing and that can help but other
times not. Any suggestions?

pref size of reduced image to be

640 x 480

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 12:30:14 AM

Archived from groups: rec.photo.digital (More info?)

On Thu, 07 Jul 2005 20:30:13 GMT, in rec.photo.digital Paul Heslop
<paul.heslop@blueyonder.co.uk> wrote:

>what's the best way to reduce image size but retain sharpness? I
>sometimes sharpen a little before reducing and that can help but other
>times not. Any suggestions?
>
>pref size of reduced image to be
>
>640 x 480

First, how are you resizing them? Simple resizing, or resampling using what
method? Second, apply sharpening after not before. Sharpening is always the
last operation performed.
----------
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://edwardgruf.com/Digital_Photography/General/index...
Anonymous
July 8, 2005 12:30:14 AM

Archived from groups: rec.photo.digital (More info?)

Always resize first, then sharpen last. Sharpening before resizing
probably won't help much. It depends a bit on which resampling scheme
you use. Bicubic will retain more sharpness than weighted average
resampling, but I think the results of weighted average + unsharp mask
look better.

http://www.digicamdata.com/
Related resources
Anonymous
July 8, 2005 12:30:14 AM

Archived from groups: rec.photo.digital (More info?)

Bicubic is a Paint Shop Pro option, but most image editors have a
variety of resampling techniques available. For example ther might be
Nearest Neighbor, Bilinear, Bicubic, Lanczos, Mitchell, and Catmull-Rom
options. The best ones are the slowest, and while when upsizing you
probably want to use the best (and slowest) choice, for downsizing you
can sometimes get better results using an averaging option and then
resharpening. This can reduce the visisbility artifacts and grain in
the original since they get "averaged out" in the downsizing process.
Different images may look better when resampled with different
techniques. There isn't really one which is always the best for every
image.

http://www.digicamdata.com/
July 8, 2005 12:30:14 AM

Archived from groups: rec.photo.digital (More info?)

Paul Heslop wrote:

> what's the best way to reduce image size but retain sharpness?

What software are you using? Makes a difference on what is best..
--

Stacey
Anonymous
July 8, 2005 12:30:14 AM

Archived from groups: rec.photo.digital (More info?)

On Thu, 07 Jul 2005, Paul Heslop <paul.heslop@blueyonder.co.uk> wrote:

>what's the best way to reduce image size but retain sharpness? I
>sometimes sharpen a little before reducing and that can help but other
>times not. Any suggestions?
>
>pref size of reduced image to be
>
>640 x 480

Hi Paul,

This is something I recently posted as part of another article:

Picture Reduction Scheme
------------------------
I posted an article in rec.photo.digital asking for suggestions on how I
should reduce these pictures while maintaining quality. (They were taken in
1600x1200 resolution with normal compression.) No one responded. So I spent
a lot of time thinking about it. I noticed that when using jpegcrop that it
only offered reductions in 1/8s. Or 12.5%, 25%, 37.5%, 50%, 62.5%, etc.
Knowing that lossless cropping meant the dimensions were still divisible by
eight, I knew that if I kept to reductions in eights I would not have
fractions of pixels. Previously my pictures were taken in VGA resolution,
or 640x480. So pictures in my albums were that size or smaller (if
cropped). I decided to use an algorithm based solely on height. With wide
ones scrolling sideways, as if they were a stitched panorama. So I first
determined whether the picture was in portrait or landscape orientation by
comparing its height and width. Then I used this algorithm:

Portrait Landscape
<= 640 100% <= 480 100%
<= 728 87.5% <= 544 87.5%
<= 848 75% <= 640 75%
<= 1008 62.5% <= 768 62.5%
<= 1280 50% <= 960 50%
<= 1600 37.5% <= 1200 37.5%

For the reduction I used Easy Thumbnails, calling it using the command line
prompt option under my album building program's control. I ended up with
pictures the same height as my existing albums.

If there was no reduction a reduced size image was not created (to save on
host server space). If both a reduced size image exists and the original
size, when you hover your cursor over the picture the tip will include
[Click for larger picture].

Don <www.donwiss.com&gt; (e-mail link at home page bottom).
Anonymous
July 8, 2005 12:30:14 AM

Archived from groups: rec.photo.digital (More info?)

Paul,
Here's the thing about downsizing photos: If you have an image that's say 1600
pixels wide or larger (or whatever), and you resize to 640 (or whatever) in one
step, it ruins the photo. And yet it is what 95% of everybody does to downsize.
Throwing away pixels in one big leap never works very well. And its why 95% of
folks web images look terrible.
So..... for instance in Paint Shop Pro (or whatever) start by resizing as a
percentage, NOT as pixels. Choose something like 85%. Click OK. Now just do
Control-Y (redo) over and over until you end up at the last possible pixel size
OVER 640 (or whatever, but 640 in your case.) In fact you can just hold down
the Control key and hit Y over and over.

At that point, go back to Resize, and now choose to resize by specific pixel
measurements. Type in your final size. 640 x 480. Click OK. Now, finally, if
you need to sharpen, use unsharp mask a tiny bit.
You'll find that downsizing in small steps and then to specific pixels on the
last step leaves small photos that are almost unchanged from the original.
Photoshop won't do a simple Control-Y for redo, so like 80% of Photoshop tasks,
what should be a simple task becomes a convoluted, unintuitive pain. But I
digress.

Give this method a whirl; I think you'll be amazed at how much nicer the photos
will downsize.

Tim

___________________________






"Paul Heslop" <paul.heslop@blueyonder.co.uk> wrote in message
news:42CD90C9.D33E7B54@blueyonder.co.uk...
what's the best way to reduce image size but retain sharpness? I
sometimes sharpen a little before reducing and that can help but other
times not. Any suggestions?

pref size of reduced image to be

640 x 480

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 2:16:38 AM

Archived from groups: rec.photo.digital (More info?)

Ed Ruf wrote:
>
> On Thu, 07 Jul 2005 20:30:13 GMT, in rec.photo.digital Paul Heslop
> <paul.heslop@blueyonder.co.uk> wrote:
>
> >what's the best way to reduce image size but retain sharpness? I
> >sometimes sharpen a little before reducing and that can help but other
> >times not. Any suggestions?
> >
> >pref size of reduced image to be
> >
> >640 x 480
>
> First, how are you resizing them? Simple resizing, or resampling using what
> method? Second, apply sharpening after not before. Sharpening is always the
> last operation performed.
> ----------
> Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
> See images taken with my CP-990/5700 & D70 at
> http://edwardgruf.com/Digital_Photography/General/index...

just straight resizing, Ed... I only recently read a little article
about resampling but it all kind of went over my head
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 2:18:14 AM

Archived from groups: rec.photo.digital (More info?)

DCD wrote:
>
> Always resize first, then sharpen last. Sharpening before resizing
> probably won't help much. It depends a bit on which resampling scheme
> you use. Bicubic will retain more sharpness than weighted average
> resampling, but I think the results of weighted average + unsharp mask
> look better.
>
> http://www.digicamdata.com/

Up to now I have just been allowing the program, paintshop or
whatever, to resize for me... but I have seen people's resized pics
which look a hell of a lot sharper than most of mine ever have.

How do you resize in this bicubic way?
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 2:18:15 AM

Archived from groups: rec.photo.digital (More info?)

On Thu, 07 Jul 2005 22:18:14 GMT, in rec.photo.digital Paul Heslop
<paul.heslop@blueyonder.co.uk> wrote:

>Up to now I have just been allowing the program, paintshop or
>whatever, to resize for me... but I have seen people's resized pics
>which look a hell of a lot sharper than most of mine ever have.

For default if you have PSP7 or later I'd set SmartSize for the resample
method. Then after resampling apply a bit of Unsharp Mask beginning with:
Raduis = 1.05
Strength = 75 - 85
Clipping = 8
as a start.
----------
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://edwardgruf.com/Digital_Photography/General/index...
Anonymous
July 8, 2005 2:32:01 AM

Archived from groups: rec.photo.digital (More info?)

Paul Heslop wrote:
>
> DCD wrote:
> >
> > Always resize first, then sharpen last. Sharpening before resizing
> > probably won't help much. It depends a bit on which resampling scheme
> > you use. Bicubic will retain more sharpness than weighted average
> > resampling, but I think the results of weighted average + unsharp mask
> > look better.
> >
> > http://www.digicamdata.com/
>
> Up to now I have just been allowing the program, paintshop or
> whatever, to resize for me... but I have seen people's resized pics
> which look a hell of a lot sharper than most of mine ever have.
>
> How do you resize in this bicubic way?
> --
Oops, never mind, found it! :o ) Looks better, for sure

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 3:51:31 AM

Archived from groups: rec.photo.digital (More info?)

In article <42CD90C9.D33E7B54@blueyonder.co.uk>, Paul Heslop says...
> what's the best way to reduce image size but retain sharpness? I
> sometimes sharpen a little before reducing and that can help but other
> times not. Any suggestions?

Try the Lanczos filter for resizing, then apply some unsharp mask with
radius 0.3 and amount 40-70. It's the resizing method I applied here:
http://www.molon.de/galleries/India/Rajahstan/Jaipur/
--

Alfred Molon
------------------------------
Olympus 4040, 5050, 5060, 7070, 8080, E300 forum at
http://groups.yahoo.com/group/MyOlympus/
Olympus E300 resource - http://myolympus.org/E300/
Anonymous
July 8, 2005 3:51:32 AM

Archived from groups: rec.photo.digital (More info?)

Alfred Molon wrote:
>
> In article <42CD90C9.D33E7B54@blueyonder.co.uk>, Paul Heslop says...
> > what's the best way to reduce image size but retain sharpness? I
> > sometimes sharpen a little before reducing and that can help but other
> > times not. Any suggestions?
>
> Try the Lanczos filter for resizing, then apply some unsharp mask with
> radius 0.3 and amount 40-70. It's the resizing method I applied here:
> http://www.molon.de/galleries/India/Rajahstan/Jaipur/
> --
>
> Alfred Molon
> ------------------------------
> Olympus 4040, 5050, 5060, 7070, 8080, E300 forum at
> http://groups.yahoo.com/group/MyOlympus/
> Olympus E300 resource - http://myolympus.org/E300/

wow, I am very impressed! Where does the lanczos filter come from? Is
it part of a program or do I need to hunt it down?
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
July 8, 2005 6:31:54 AM

Archived from groups: rec.photo.digital (More info?)

Destin_FL wrote:

> Paul,
> Here's the thing about downsizing photos: If you have an image that's say
> 1600 pixels wide or larger (or whatever), and you resize to 640 (or
> whatever) in one
> step, it ruins the photo. And yet it is what 95% of everybody does to
> downsize.
> Throwing away pixels in one big leap never works very well. And its why
> 95% of folks web images look terrible.
> So..... for instance in Paint Shop Pro (or whatever) start by resizing as
> a
> percentage, NOT as pixels. Choose something like 85%. Click OK. Now
> just do Control-Y (redo) over and over until you end up at the last
> possible pixel size
> OVER 640 (or whatever, but 640 in your case.) In fact you can just hold
> down the Control key and hit Y over and over.
>

Yep, that's the key. I've found it works well for sharpening too. Rather
than trying to do USM in one step, I do part of it at something like radius
1.6 80% and then again at radius .3 50% rather than trying to do a radius
1.0 at 120%.

--

Stacey
Anonymous
July 8, 2005 7:20:30 AM

Archived from groups: rec.photo.digital (More info?)

I use Imagewalker.com it seems to do the job and I can use it automatically
resize any number of photos. It seems to keep the sharpness pretty well,
The only disadvantage with it is that I must make 2 passes to get the
pictures and other stuff setup correctly. I use the thumbnail sizes to
resize the pictures first to 640X480 and then run it again to make the
thumbnails of 77 x 97.
You can see the examples of this at http://mysite.verizon.net/stevem5215/

Steve

"Paul Heslop" <paul.heslop@blueyonder.co.uk> wrote in message
news:42CD90C9.D33E7B54@blueyonder.co.uk...
> what's the best way to reduce image size but retain sharpness? I
> sometimes sharpen a little before reducing and that can help but other
> times not. Any suggestions?
>
> pref size of reduced image to be
>
> 640 x 480
>
> --
> Paul (And I'm, like, "yeah, whatever!")
> -------------------------------------------------------
> Stop and Look
> http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 7:51:56 AM

Archived from groups: rec.photo.digital (More info?)

On Fri, 08 Jul 2005 03:20:30 GMT, Steve m... wrote:

> I use Imagewalker.com it seems to do the job and I can use it automatically
> resize any number of photos. It seems to keep the sharpness pretty well,
> The only disadvantage with it is that I must make 2 passes to get the
> pictures and other stuff setup correctly. I use the thumbnail sizes to
> resize the pictures first to 640X480 and then run it again to make the
> thumbnails of 77 x 97.

JpegSizer will create thumbs and full-size images in a single pass.

Free trial at the link below.

Peter
--
Versatile image resizer for web pages, email attachments
and online photo-printing services
http://jpegsizer.tangotools.com/?s=ng
Anonymous
July 8, 2005 8:06:49 AM

Archived from groups: rec.photo.digital (More info?)

DCD wrote:
>
> Bicubic is a Paint Shop Pro option, but most image editors have a
> variety of resampling techniques available. For example ther might be
> Nearest Neighbor, Bilinear, Bicubic, Lanczos, Mitchell, and Catmull-Rom
> options. The best ones are the slowest, and while when upsizing you
> probably want to use the best (and slowest) choice, for downsizing you
> can sometimes get better results using an averaging option and then
> resharpening. This can reduce the visisbility artifacts and grain in
> the original since they get "averaged out" in the downsizing process.
> Different images may look better when resampled with different
> techniques. There isn't really one which is always the best for every
> image.
>
> http://www.digicamdata.com/

thanks for the thorough info!
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 8:07:14 AM

Archived from groups: rec.photo.digital (More info?)

Ed Ruf wrote:
>
> On Thu, 07 Jul 2005 22:18:14 GMT, in rec.photo.digital Paul Heslop
> <paul.heslop@blueyonder.co.uk> wrote:
>
> >Up to now I have just been allowing the program, paintshop or
> >whatever, to resize for me... but I have seen people's resized pics
> >which look a hell of a lot sharper than most of mine ever have.
>
> For default if you have PSP7 or later I'd set SmartSize for the resample
> method. Then after resampling apply a bit of Unsharp Mask beginning with:
> Raduis = 1.05
> Strength = 75 - 85
> Clipping = 8
> as a start.
> ----------
> Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
> See images taken with my CP-990/5700 & D70 at
> http://edwardgruf.com/Digital_Photography/General/index...

thanks Ed, I'll give this a try
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 8:09:01 AM

Archived from groups: rec.photo.digital (More info?)

Stacey wrote:
>
> Paul Heslop wrote:
>
> > what's the best way to reduce image size but retain sharpness?
>
> What software are you using? Makes a difference on what is best..
> --
>
> Stacey

I'm hovering between Paintshop Pro 8, photoshop CS and photoshop
elements. I have no idea why I have both of those except I hate to
uninstall stuff unless I know it's useless.

I prefer Paintshop because I'm more used to it.
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
July 8, 2005 8:09:02 AM

Archived from groups: rec.photo.digital (More info?)

Paul Heslop wrote:

> Stacey wrote:
>>
>> Paul Heslop wrote:
>>
>> > what's the best way to reduce image size but retain sharpness?
>>
>> What software are you using? Makes a difference on what is best..
>> --
>>
>> Stacey
>
> I'm hovering between Paintshop Pro 8, photoshop CS and photoshop
> elements. I have no idea why I have both of those except I hate to
> uninstall stuff unless I know it's useless.
>
> I prefer Paintshop because I'm more used to it.


If using PSCS, try downsampling in a couple of steps using bicubic sharper
or load these free actions and try them.

http://www.savefile.com/files/3297443

They were used to downsample this image.

http://img.villagephotos.com/p/2005-1/937049/fly.jpg

The trick used for this action is downsample then USM .3 radius at various %
between each step, then fade the USM ~80%. If going through 3 steps try
120% 100% and 80% to start with.

--

Stacey
Anonymous
July 8, 2005 8:10:44 AM

Archived from groups: rec.photo.digital (More info?)

Don Wiss wrote:
>
> On Thu, 07 Jul 2005, Paul Heslop <paul.heslop@blueyonder.co.uk> wrote:
>
> >what's the best way to reduce image size but retain sharpness? I
> >sometimes sharpen a little before reducing and that can help but other
> >times not. Any suggestions?
> >
> >pref size of reduced image to be
> >
> >640 x 480
>
> Hi Paul,
>
> This is something I recently posted as part of another article:
>
> Picture Reduction Scheme
> ------------------------
> I posted an article in rec.photo.digital asking for suggestions on how I
> should reduce these pictures while maintaining quality. (They were taken in
> 1600x1200 resolution with normal compression.) No one responded. So I spent
> a lot of time thinking about it. I noticed that when using jpegcrop that it
> only offered reductions in 1/8s. Or 12.5%, 25%, 37.5%, 50%, 62.5%, etc.
> Knowing that lossless cropping meant the dimensions were still divisible by
> eight, I knew that if I kept to reductions in eights I would not have
> fractions of pixels. Previously my pictures were taken in VGA resolution,
> or 640x480. So pictures in my albums were that size or smaller (if
> cropped). I decided to use an algorithm based solely on height. With wide
> ones scrolling sideways, as if they were a stitched panorama. So I first
> determined whether the picture was in portrait or landscape orientation by
> comparing its height and width. Then I used this algorithm:
>
> Portrait Landscape
> <= 640 100% <= 480 100%
> <= 728 87.5% <= 544 87.5%
> <= 848 75% <= 640 75%
> <= 1008 62.5% <= 768 62.5%
> <= 1280 50% <= 960 50%
> <= 1600 37.5% <= 1200 37.5%
>
> For the reduction I used Easy Thumbnails, calling it using the command line
> prompt option under my album building program's control. I ended up with
> pictures the same height as my existing albums.
>
> If there was no reduction a reduced size image was not created (to save on
> host server space). If both a reduced size image exists and the original
> size, when you hover your cursor over the picture the tip will include
> [Click for larger picture].
>
> Don <www.donwiss.com&gt; (e-mail link at home page bottom).

Thanks Don, I think i actually have easy thumbnails installed too so
it's worth a try. So many options so few brain cells to be used :o ))

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 8:12:03 AM

Archived from groups: rec.photo.digital (More info?)

Destin_FL wrote:
>
> Paul,
> Here's the thing about downsizing photos: If you have an image that's say 1600
> pixels wide or larger (or whatever), and you resize to 640 (or whatever) in one
> step, it ruins the photo. And yet it is what 95% of everybody does to downsize.
> Throwing away pixels in one big leap never works very well. And its why 95% of
> folks web images look terrible.
> So..... for instance in Paint Shop Pro (or whatever) start by resizing as a
> percentage, NOT as pixels. Choose something like 85%. Click OK. Now just do
> Control-Y (redo) over and over until you end up at the last possible pixel size
> OVER 640 (or whatever, but 640 in your case.) In fact you can just hold down
> the Control key and hit Y over and over.
>
> At that point, go back to Resize, and now choose to resize by specific pixel
> measurements. Type in your final size. 640 x 480. Click OK. Now, finally, if
> you need to sharpen, use unsharp mask a tiny bit.
> You'll find that downsizing in small steps and then to specific pixels on the
> last step leaves small photos that are almost unchanged from the original.
> Photoshop won't do a simple Control-Y for redo, so like 80% of Photoshop tasks,
> what should be a simple task becomes a convoluted, unintuitive pain. But I
> digress.
>
> Give this method a whirl; I think you'll be amazed at how much nicer the photos
> will downsize.
>
> Tim
>
woow... intense stuff... this is going to take a lot of
experimentation! Thanks Tim.

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 8:13:03 AM

Archived from groups: rec.photo.digital (More info?)

"Steve m..." wrote:
>
> I use Imagewalker.com it seems to do the job and I can use it automatically
> resize any number of photos. It seems to keep the sharpness pretty well,
> The only disadvantage with it is that I must make 2 passes to get the
> pictures and other stuff setup correctly. I use the thumbnail sizes to
> resize the pictures first to 640X480 and then run it again to make the
> thumbnails of 77 x 97.
> You can see the examples of this at http://mysite.verizon.net/stevem5215/
>
> Steve
>
Thanks Steve, that's one I'd never heard of before!
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 11:47:51 AM

Archived from groups: rec.photo.digital (More info?)

In article <42CDAA9A.63F3DAD5@blueyonder.co.uk>, Paul Heslop says...

> > > what's the best way to reduce image size but retain sharpness? I
> > > sometimes sharpen a little before reducing and that can help but other
> > > times not. Any suggestions?
> >
> > Try the Lanczos filter for resizing, then apply some unsharp mask with
> > radius 0.3 and amount 40-70. It's the resizing method I applied here:
> > http://www.molon.de/galleries/India/Rajahstan/Jaipur/

> wow, I am very impressed! Where does the lanczos filter come from? Is
> it part of a program or do I need to hunt it down?

It's available for instance with Imagemagick or Irfanview.
--

Alfred Molon
------------------------------
Olympus 4040, 5050, 5060, 7070, 8080, E300 forum at
http://groups.yahoo.com/group/MyOlympus/
Olympus E300 resource - http://myolympus.org/E300/
Anonymous
July 8, 2005 12:13:52 PM

Archived from groups: rec.photo.digital (More info?)

On Thu, 07 Jul 2005 20:30:13 GMT, Paul Heslop wrote:

> what's the best way to reduce image size but retain sharpness? I
> sometimes sharpen a little before reducing and that can help but other
> times not. Any suggestions?
>
> pref size of reduced image to be
>
> 640 x 480

JpegSizer will automatically re-sharpen images after resizing.

Free trial available at the link below.

Peter
--
Versatile image resizer for web pages, email attachments
and online photo-printing services
http://jpegsizer.tangotools.com/?s=ng
Anonymous
July 8, 2005 3:13:08 PM

Archived from groups: rec.photo.digital (More info?)

Paul Heslop <paul.heslop@blueyonder.co.uk> writes:

> what's the best way to reduce image size but retain sharpness? I
> sometimes sharpen a little before reducing and that can help but other
> times not. Any suggestions?

Sharpening before reducing does not sound useful, as the effect will
likely be lost at the lower resolution. Proper reducing will
automatically make it sharp enough.

> pref size of reduced image to be
>
> 640 x 480

That's my preferred size too. See the following:

http://img.ourdoings.com/windows.html

If you edit the DO.SH file, removing the last line that starts with ZIP,
it will do what you want for a batch of photos. It uses pnmscale from
the netpnm suite, which does very good resizing. If the results still
aren't as sharp as you think they could be, replace "cjpeg" with
"cjpeg -quality 85" to get higher quality images at the cost of more
size. I find the default (75) quite good enough myself.
July 8, 2005 3:14:55 PM

Archived from groups: rec.photo.digital (More info?)

Stacey wrote:
> Paul Heslop wrote:
>
>
>>Stacey wrote:
>>
>>>Paul Heslop wrote:
>>>
>>>
>>>>what's the best way to reduce image size but retain sharpness?
>>>
>>>What software are you using? Makes a difference on what is best..
>>>--
>>>
>>> Stacey
>>
>>I'm hovering between Paintshop Pro 8, photoshop CS and photoshop
>>elements. I have no idea why I have both of those except I hate to
>>uninstall stuff unless I know it's useless.
>>
>>I prefer Paintshop because I'm more used to it.
>
>
>
> If using PSCS, try downsampling in a couple of steps using bicubic sharper
> or load these free actions and try them.
>
> http://www.savefile.com/files/3297443
>
> They were used to downsample this image.
>
> http://img.villagephotos.com/p/2005-1/937049/fly.jpg
>
> The trick used for this action is downsample then USM .3 radius at various %
> between each step, then fade the USM ~80%. If going through 3 steps try
> 120% 100% and 80% to start with.
>
Ummm, server keeps losing connection.
Anonymous
July 8, 2005 3:17:36 PM

Archived from groups: rec.photo.digital (More info?)

On Fri, 08 Jul 2005 02:27:16 -0400, in rec.photo.digital Stacey
<fotocord@yahoo.com> wrote:

>If using PSCS, try downsampling in a couple of steps using bicubic sharper
>or load these free actions and try them.
>http://www.savefile.com/files/3297443
>
>They were used to downsample this image.
>http://img.villagephotos.com/p/2005-1/937049/fly.jpg


This is way over sharpened. You can easily see the ringing in the
flower edges to the right of the fly.
________________________________________________________
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://EdwardGRuf.com
Anonymous
July 8, 2005 3:27:43 PM

Archived from groups: rec.photo.digital (More info?)

Alfred Molon wrote:
>
> In article <42CDAA9A.63F3DAD5@blueyonder.co.uk>, Paul Heslop says...
>
> > > > what's the best way to reduce image size but retain sharpness? I
> > > > sometimes sharpen a little before reducing and that can help but other
> > > > times not. Any suggestions?
> > >
> > > Try the Lanczos filter for resizing, then apply some unsharp mask with
> > > radius 0.3 and amount 40-70. It's the resizing method I applied here:
> > > http://www.molon.de/galleries/India/Rajahstan/Jaipur/
>
> > wow, I am very impressed! Where does the lanczos filter come from? Is
> > it part of a program or do I need to hunt it down?
>
> It's available for instance with Imagemagick or Irfanview.
> --
>
> Alfred Molon
> ------------------------------
> Olympus 4040, 5050, 5060, 7070, 8080, E300 forum at
> http://groups.yahoo.com/group/MyOlympus/
> Olympus E300 resource - http://myolympus.org/E300/

thanks Alfie... off to have a search round now
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
July 8, 2005 5:03:09 PM

Archived from groups: rec.photo.digital (More info?)

Ed Ruf wrote:


>>
>>They were used to downsample this image.
>>http://img.villagephotos.com/p/2005-1/937049/fly.jpg
>
>
> This is way over sharpened.

Sorry you don't like it. It's a bitch, one day someone complains an image is
too soft, the next someone will say the same image is oversharpened, might
be different monitors? Can't please everyone...

BTW I looked at your site and personally think all your images too way too
soft so maybe it's a matter of taste? Unless you believe there is some
mathmatical formula for this?
--

Stacey
Anonymous
July 8, 2005 5:12:00 PM

Archived from groups: rec.photo.digital (More info?)

On Fri, 08 Jul 2005 13:03:09 -0400, in rec.photo.digital Stacey
<fotocord@yahoo.com> wrote:

>Sorry you don't like it. It's a bitch, one day someone complains an image is
>too soft, the next someone will say the same image is oversharpened, might
>be different monitors? Can't please everyone...

No look at it on my iiyama 22" CRT and Samsung 21" LCD at work, both
of which have been calibrated with a Colorvision Spyder.

>BTW I looked at your site and personally think all your images too way too
>soft so maybe it's a matter of taste? Unless you believe there is some
>mathmatical formula for this?

Look zoomed in at your fly image, specifically, the edges of the red
flower to the right. You can see the ringing, ie the halo around the
edges. This is an artifact from over sharpening. This halo isn't there
in real life.
________________________________________________________
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://EdwardGRuf.com
Anonymous
July 8, 2005 7:09:02 PM

Archived from groups: rec.photo.digital (More info?)

Stacey wrote:
>
> Paul Heslop wrote:
>
> > Stacey wrote:
> >>
> >> Paul Heslop wrote:
> >>
> >> > what's the best way to reduce image size but retain sharpness?
> >>
> >> What software are you using? Makes a difference on what is best..
> >> --
> >>
> >> Stacey
> >
> > I'm hovering between Paintshop Pro 8, photoshop CS and photoshop
> > elements. I have no idea why I have both of those except I hate to
> > uninstall stuff unless I know it's useless.
> >
> > I prefer Paintshop because I'm more used to it.
>
> If using PSCS, try downsampling in a couple of steps using bicubic sharper
> or load these free actions and try them.
>
> http://www.savefile.com/files/3297443
>
> They were used to downsample this image.
>
> http://img.villagephotos.com/p/2005-1/937049/fly.jpg
>
> The trick used for this action is downsample then USM .3 radius at various %
> between each step, then fade the USM ~80%. If going through 3 steps try
> 120% 100% and 80% to start with.
>
> --
>
> Stacey

that's beautiful. I did find some actions and download them but they
didn't show up in the actions tool
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
July 8, 2005 7:09:03 PM

Archived from groups: rec.photo.digital (More info?)

Paul Heslop wrote:

> I did find some actions and download them but they
> didn't show up in the actions tool


You have to copy them to program files/photoshop/presets/photoshop actions.
Then open PS and click on the little arrow in the upper corner of the
actions pallet and select "Load actions". Then point it to this action set,
click OK and then it will be in the action pallet.
--

Stacey
Anonymous
July 8, 2005 8:19:33 PM

Archived from groups: rec.photo.digital (More info?)

Bruce Lewis wrote:
>
> Paul Heslop <paul.heslop@blueyonder.co.uk> writes:
>
> > what's the best way to reduce image size but retain sharpness? I
> > sometimes sharpen a little before reducing and that can help but other
> > times not. Any suggestions?
>
> Sharpening before reducing does not sound useful, as the effect will
> likely be lost at the lower resolution. Proper reducing will
> automatically make it sharp enough.
>
> > pref size of reduced image to be
> >
> > 640 x 480
>
> That's my preferred size too. See the following:
>
> http://img.ourdoings.com/windows.html
>
> If you edit the DO.SH file, removing the last line that starts with ZIP,
> it will do what you want for a batch of photos. It uses pnmscale from
> the netpnm suite, which does very good resizing. If the results still
> aren't as sharp as you think they could be, replace "cjpeg" with
> "cjpeg -quality 85" to get higher quality images at the cost of more
> size. I find the default (75) quite good enough myself.

Thanks bruce, I'll add it to my list of experiments :o ))
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 8:20:07 PM

Archived from groups: rec.photo.digital (More info?)

Peter Martin wrote:
>
> On Thu, 07 Jul 2005 20:30:13 GMT, Paul Heslop wrote:
>
> > what's the best way to reduce image size but retain sharpness? I
> > sometimes sharpen a little before reducing and that can help but other
> > times not. Any suggestions?
> >
> > pref size of reduced image to be
> >
> > 640 x 480
>
> JpegSizer will automatically re-sharpen images after resizing.
>
> Free trial available at the link below.
>
> Peter
> --
> Versatile image resizer for web pages, email attachments
> and online photo-printing services
> http://jpegsizer.tangotools.com/?s=ng

thanks Peter... , I'm going to have new programs falling off the end
of my hard drive :o )
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 8, 2005 8:46:24 PM

Archived from groups: rec.photo.digital (More info?)

Paul Heslop wrote:

> just straight resizing, Ed... I only recently read a little article
> about resampling but it all kind of went over my head

Resizing as in defining width and height in the HTML, and leaving the
actual image files at their original size? Not sure how concerned about
load times and bandiwdth you are for the particular presentation, but
you might want to consider looking into resampling. The iamges will
load faster and chew up less bandwidth. You can always just IMG anchor
a downsampled "thumbnail" and have it link to a full size image, if you
want to give visitors that option.


--
E-mail fudged to thwart spammers.
Transpose the c's and a's in my e-mail address to reply.
July 8, 2005 11:05:12 PM

Archived from groups: rec.photo.digital (More info?)

Ed Ruf wrote:


>
> Look zoomed in at your fly image, specifically, the edges of the red
> flower to the right.

First off why would anyone be zooming an image past 100%?

> You can see the ringing, ie the halo around the
> edges. This is an artifact from over sharpening. This halo isn't there
> in real life.

The white edge on that one petal to the right of the fly? Yes it -IS- there
is real life in the unsharpened RAW file, I just looked. You're looking
for this stuff so hard you forget sometimes real things have a white edge
to them! Yes it's probably sharpened too much for some people's taste. I
like the way it looks, especially in print.

Again sorry if you don't like this image, I've sold a couple of dozen of
these so someone likes it. :-)
--

Stacey
Anonymous
July 9, 2005 1:17:23 AM

Archived from groups: rec.photo.digital (More info?)

Isaiah Beard wrote:
>
> Paul Heslop wrote:
>
> > just straight resizing, Ed... I only recently read a little article
> > about resampling but it all kind of went over my head
>
> Resizing as in defining width and height in the HTML, and leaving the
> actual image files at their original size? Not sure how concerned about
> load times and bandiwdth you are for the particular presentation, but
> you might want to consider looking into resampling. The iamges will
> load faster and chew up less bandwidth. You can always just IMG anchor
> a downsampled "thumbnail" and have it link to a full size image, if you
> want to give visitors that option.
>
> --
> E-mail fudged to thwart spammers.
> Transpose the c's and a's in my e-mail address to reply.

Yes, thanks, I'm starting to get the hang now :o )

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 9, 2005 1:19:15 AM

Archived from groups: rec.photo.digital (More info?)

Stacey wrote:
>
> Paul Heslop wrote:
>
> > I did find some actions and download them but they
> > didn't show up in the actions tool
>
> You have to copy them to program files/photoshop/presets/photoshop actions.
> Then open PS and click on the little arrow in the upper corner of the
> actions pallet and select "Load actions". Then point it to this action set,
> click OK and then it will be in the action pallet.
> --
>
> Stacey

That's what I did with the ones I downloaded, and I don't know if it's
just me or what but I can't get that download of yours to work... the
web itself seems very slow here, and I'm on a 4mb connection!
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 9, 2005 1:19:16 AM

Archived from groups: rec.photo.digital (More info?)

Paul Heslop wrote:
> Stacey wrote:
>>
>> Paul Heslop wrote:
>>
>>> I did find some actions and download them but they
>>> didn't show up in the actions tool
>>
>> You have to copy them to program files/photoshop/presets/photoshop
>> actions. Then open PS and click on the little arrow in the upper
>> corner of the actions pallet and select "Load actions". Then point
>> it to this action set, click OK and then it will be in the action
>> pallet. --
>>
>> Stacey
>
> That's what I did with the ones I downloaded, and I don't know if
> it's
> just me or what but I can't get that download of yours to work...
> the
> web itself seems very slow here, and I'm on a 4mb connection!

My favorite for individual images installs itself in the File -
Automate menu
http://www.imphotography.com/downloads/ssimagesize.htm
Nice Windows interface that makes it very clear and easy for me,
dullard that I am.

For batches, Irfanview is just fine.

And my favorite price, too.

--
Frank ess
Anonymous
July 9, 2005 1:19:38 AM

Archived from groups: rec.photo.digital (More info?)

Dave wrote:
>
> Stacey wrote:
> > Paul Heslop wrote:
> >
> >
> >>Stacey wrote:
> >>
> >>>Paul Heslop wrote:
> >>>
> >>>
> >>>>what's the best way to reduce image size but retain sharpness?
> >>>
> >>>What software are you using? Makes a difference on what is best..
> >>>--
> >>>
> >>> Stacey
> >>
> >>I'm hovering between Paintshop Pro 8, photoshop CS and photoshop
> >>elements. I have no idea why I have both of those except I hate to
> >>uninstall stuff unless I know it's useless.
> >>
> >>I prefer Paintshop because I'm more used to it.
> >
> >
> >
> > If using PSCS, try downsampling in a couple of steps using bicubic sharper
> > or load these free actions and try them.
> >
> > http://www.savefile.com/files/3297443
> >
> > They were used to downsample this image.
> >
> > http://img.villagephotos.com/p/2005-1/937049/fly.jpg
> >
> > The trick used for this action is downsample then USM .3 radius at various %
> > between each step, then fade the USM ~80%. If going through 3 steps try
> > 120% 100% and 80% to start with.
> >
> Ummm, server keeps losing connection.

Oh good, I thought it was me :o )
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 9, 2005 1:20:16 AM

Archived from groups: rec.photo.digital (More info?)

Stacey wrote:
>
> Ed Ruf wrote:
>
> >>
> >>They were used to downsample this image.
> >>http://img.villagephotos.com/p/2005-1/937049/fly.jpg
> >
> >
> > This is way over sharpened.
>
> Sorry you don't like it. It's a bitch, one day someone complains an image is
> too soft, the next someone will say the same image is oversharpened, might
> be different monitors? Can't please everyone...
>
it pleased me :o )
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 9, 2005 1:20:50 AM

Archived from groups: rec.photo.digital (More info?)

Ed Ruf wrote:
>
> On Fri, 08 Jul 2005 13:03:09 -0400, in rec.photo.digital Stacey
> <fotocord@yahoo.com> wrote:
>
> >Sorry you don't like it. It's a bitch, one day someone complains an image is
> >too soft, the next someone will say the same image is oversharpened, might
> >be different monitors? Can't please everyone...
>
> No look at it on my iiyama 22" CRT and Samsung 21" LCD at work, both
> of which have been calibrated with a Colorvision Spyder.
>
> >BTW I looked at your site and personally think all your images too way too
> >soft so maybe it's a matter of taste? Unless you believe there is some
> >mathmatical formula for this?
>
> Look zoomed in at your fly image, specifically, the edges of the red
> flower to the right. You can see the ringing, ie the halo around the
> edges. This is an artifact from over sharpening. This halo isn't there
> in real life.
> ________________________________________________________

but is that not also from it being a reduced image which is sharpened?

--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 9, 2005 1:29:37 AM

Archived from groups: rec.photo.digital (More info?)

"Paul Heslop" <paul.heslop@blueyonder.co.uk> wrote in message
news:42CE6323.B69522DB@blueyonder.co.uk...
SNIP
>> > Where does the lanczos filter come from? Is
>> > it part of a program or do I need to hunt it down?
>>
>> It's available for instance with Imagemagick or Irfanview.

Here's some more background on the subject:
<http://www.xs4all.nl/~bvdwolf/main/foto/down_sample/dow...;
and some image examples:
<http://www.xs4all.nl/~bvdwolf/main/foto/down_sample/exa...;

Bart
Anonymous
July 9, 2005 1:29:38 AM

Archived from groups: rec.photo.digital (More info?)

Bart van der Wolf wrote:
>
> "Paul Heslop" <paul.heslop@blueyonder.co.uk> wrote in message
> news:42CE6323.B69522DB@blueyonder.co.uk...
> SNIP
> >> > Where does the lanczos filter come from? Is
> >> > it part of a program or do I need to hunt it down?
> >>
> >> It's available for instance with Imagemagick or Irfanview.
>
> Here's some more background on the subject:
> <http://www.xs4all.nl/~bvdwolf/main/foto/down_sample/dow...;
> and some image examples:
> <http://www.xs4all.nl/~bvdwolf/main/foto/down_sample/exa...;
>
> Bart

Thanks Bart, I found it in Irfanview... It seems to work incredibly
well
--
Paul (And I'm, like, "yeah, whatever!")
-------------------------------------------------------
Stop and Look
http://www.geocities.com/dreamst8me/
Anonymous
July 9, 2005 12:41:57 PM

Archived from groups: rec.photo.digital (More info?)

On Fri, 08 Jul 2005 19:05:12 -0400, in rec.photo.digital Stacey
<fotocord@yahoo.com> wrote:

>Ed Ruf wrote:
>> Look zoomed in at your fly image, specifically, the edges of the red
>> flower to the right.
>
>First off why would anyone be zooming an image past 100%?

To look for sharpening artifacts. We were discussing sharpening techniques.

>> You can see the ringing, ie the halo around the
>> edges. This is an artifact from over sharpening. This halo isn't there
>> in real life.
>
>The white edge on that one petal to the right of the fly? Yes it -IS- there
>is real life in the unsharpened RAW file, I just looked. You're looking
>for this stuff so hard you forget sometimes real things have a white edge
>to them! Yes it's probably sharpened too much for some people's taste. I
>like the way it looks, especially in print.
>
>Again sorry if you don't like this image, I've sold a couple of dozen of
>these so someone likes it. :-)

First, I never said I didn't like the image, just that your reduced version
which you gave a link to in the discussion regarding sharpening techniques
appeared to have sharpening artifacts at my first glance.

You comments about prints and selling this image I would assume no doubt
are in reference to the full resolution version, correct? If so we may or
may not be commenting on the same thing. Given what info I have at hand, I
can't make any comment other than, yes the sharpness of an image may be a
personal thing.

I would like to see a full resolution version both before and after
sharpening if you would indulge me. I will admit I've never been one to
aggressively sharpen images and would like to see if I'm being too
conservative. If you don't want to post a link you could e-mail the images
to me at the address in my sig, there is no size limit on this account.
----------
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://edwardgruf.com/Digital_Photography/General/index...
Anonymous
July 9, 2005 5:10:09 PM

Archived from groups: rec.photo.digital (More info?)

On Sat, 09 Jul 2005 18:50:09 +0200, in rec.photo.digital Hans-Georg Michna
<hans-georgNoEmailPlease@michna.com> wrote:

>will not need any additional processing. The best resize filter
>is Lanczos, but I'm not sure whether it helps at all when the
>size is reduced. It definitely helps somewhat when upscaling a
>photo, but you are downscaling. I think, much simpler algorithms
>will still do a fair job when downsampling.

Absolute statements are usually never absolutely correct. I'd agree Lanczos
is one of the best. Have you looked at some of the more advanced routines
in Qimage as well. I've found them to be better at times.
----------
Ed Ruf Lifetime AMA# 344007 (Usenet@EdwardG.Ruf.com)
See images taken with my CP-990/5700 & D70 at
http://edwardgruf.com/Digital_Photography/General/index...
Anonymous
July 9, 2005 6:27:27 PM

Archived from groups: rec.photo.digital (More info?)

Hans-Georg Michna <hans-georgNoEmailPlease@michna.com> wrote:

>The idea to do the reduction in several steps is snake oil.
>Forget that.

It certainly sounds like snake oil to me. Plus a lot of work. I've had no
quality loss using Thumb Nails Plus with the algorithm set to [Smart].
There are many algorithms to choose from, and I don't have the time or
inclination to see if one is better than what the program author decides.

My two most recent parade albums used Thumb Nails Plus and the only in
1/8's scheme I posted about before. Calling in in command line mode and
under program allowed me to reduce hundreds of pictures in only a few
minutes. The amount of time spent if I followed other people's suggestions
would be much greater.

Here is one example. I don't see that the reduced picture needs any
sharpening. (Jpeg compression on reduced one is 80%. Original is "normal.")

http://donwiss.com/pictures/Mermaid-2005/h0005.htm
http://donwiss.com/pictures/Mermaid-2005/0005.jpg

Don <www.donwiss.com&gt; (e-mail link at home page bottom).
July 9, 2005 7:25:42 PM

Archived from groups: rec.photo.digital (More info?)

Paul Heslop wrote:

>Often it's probably my eyes anyway, as i can
> look at a picture once, it looks fine, then i look again and it looks
> a mess... and the other way round too.

Color balance is the same way. You think you have it nailed, come back later
and it has an obvious color shift. That's pretty nomal..
--

Stacey
July 9, 2005 7:31:04 PM

Archived from groups: rec.photo.digital (More info?)

Ed Ruf wrote:

> On Fri, 08 Jul 2005 19:05:12 -0400, in rec.photo.digital Stacey
> <fotocord@yahoo.com> wrote:
>
>>Ed Ruf wrote:
>>> Look zoomed in at your fly image, specifically, the edges of the red
>>> flower to the right.
>>
>>First off why would anyone be zooming an image past 100%?
>
> To look for sharpening artifacts. We were discussing sharpening
> techniques.

I guess I'm more interested in the impact the final image has than looking
past 100% for some details that you won't see viewing the actual image?


>
> I would like to see a full resolution version both before and after
> sharpening if you would indulge me. I will admit I've never been one to
> aggressively sharpen images and would like to see if I'm being too
> conservative.

Personally I think you are but again I might like what some people consider
overly sharpened images? I also like high contrast while some people like
soft looking images. I think it's a personal taste issue and it's not
something you can say this is too soft or too harsh etc. It's up to the
person working on the image to decide?

> If you don't want to post a link you could e-mail the images
> to me at the address in my sig, there is no size limit on this account.

I'll dig up some copies and send them to ya.

--

Stacey
!