On Mon, 23 Jan 2006 20:47:38 GMT, Commodore Joe Redcloud©
wrote:

On Mon, 23 Jan 2006 15:42:28 -0500, JohnH wrote:

On Mon, 23 Jan 2006 15:08:11 GMT, Commodore Joe Redcloud©
wrote:

On Mon, 23 Jan 2006 07:44:01 -0700, "RG" wrote:



I was using some HP photo editing software that came with the camera ...
when you want to downsize a image file it offers two sizes - one
recommended for e-mail and one recommended for images for a web page.
Then, after selecting one of these, it offers a choice of decreasing it by
pixels or by percent of original. This is the part I am not sure about.
I'll try both and see if I can determine the difference, if any.

Shouldn't be any difference. Reducing a 3000X2000 image to a specified
1500X1000 pixels should give the exact same result as a request to reduce
the image by 50%, within the same program. Same resizing and resampling
algorhythms should be used to get there.


More advanced programs such as Photoshop and Paint Shop Pro give you a
choice of several reduction methods and optimizations. I use Irfan
view also, and it does a pretty crude job of resizing, and the
resulting file size is always much larger than those produced by more
sophisticated programs.

Irfanview is mostly useful as a quick viewer when you want to go
through a folder of photos. It's not really intended as an editor.


Commodore Joe Redcloud©

With Irfanview, you can make the file size as small as you want.

You are not understanding the issue. If I take a 1 MB file that is
1200 x 1200 and reduce it to 600x600 in both programs, the resulting
files will be vastly different in size. Irfanview is a handy viewer
and I use it all the time, but it was never intended as an editor, and
that portion of it is very crude.




Commodore Joe Redcloud©

Could that be because the quality is different in the two programs?
--
John H

******Have a spectacular day!******

On Mon, 23 Jan 2006 20:47:38 GMT, Commodore Joe Redcloud©
wrote:

On Mon, 23 Jan 2006 15:42:28 -0500, JohnH wrote:

On Mon, 23 Jan 2006 15:08:11 GMT, Commodore Joe Redcloud©
wrote:

On Mon, 23 Jan 2006 07:44:01 -0700, "RG" wrote:



I was using some HP photo editing software that came with the camera ...
when you want to downsize a image file it offers two sizes - one
recommended for e-mail and one recommended for images for a web page.
Then, after selecting one of these, it offers a choice of decreasing it by
pixels or by percent of original. This is the part I am not sure about.
I'll try both and see if I can determine the difference, if any.

Shouldn't be any difference. Reducing a 3000X2000 image to a specified
1500X1000 pixels should give the exact same result as a request to reduce
the image by 50%, within the same program. Same resizing and resampling
algorhythms should be used to get there.


More advanced programs such as Photoshop and Paint Shop Pro give you a
choice of several reduction methods and optimizations. I use Irfan
view also, and it does a pretty crude job of resizing, and the
resulting file size is always much larger than those produced by more
sophisticated programs.

Irfanview is mostly useful as a quick viewer when you want to go
through a folder of photos. It's not really intended as an editor.


Commodore Joe Redcloud©

With Irfanview, you can make the file size as small as you want.

You are not understanding the issue. If I take a 1 MB file that is
1200 x 1200 and reduce it to 600x600 in both programs, the resulting
files will be vastly different in size. Irfanview is a handy viewer
and I use it all the time, but it was never intended as an editor, and
that portion of it is very crude.




Commodore Joe Redcloud©

I just resized a 3.74mb (50% reduction) pic in Irfanview with a resulting
filesize of 1.22mb. The same thing in Photoshop Elements resulted in a file
size of 1.629mb. Both were resized at the highest jpg quality.

Something else is going on here besides just the software being used. If I
reduce the dimensions by 50%, I'd expect the file size to be about 25% of
the original. Irfanview is closer to the expectation.
--
John H

******Have a spectacular day!******

"Harry Krause" wrote in message
...


I love it. Keep it up! Maybe it is a 50% reduction in file size, not a 50%
reduction in real estate. Maybe not. And you do know what happens every
time you save a *.jpg file, right? It just keeps on compressing itself.

I noticed that many of the image programs offer a compression option when
saving .jpg files. You can select anything from "lots" of compression for
smaller files and low quality or "no" compression for high quality but
bigger file sizes. Are you suggesting that they become compressed anyway,
by default?

Eisboch

On Mon, 23 Jan 2006 16:35:00 -0500, Harry Krause
wrote:

JohnH wrote:
On Mon, 23 Jan 2006 20:47:38 GMT, Commodore Joe Redcloud©
wrote:

On Mon, 23 Jan 2006 15:42:28 -0500, JohnH wrote:

On Mon, 23 Jan 2006 15:08:11 GMT, Commodore Joe Redcloud©
wrote:

On Mon, 23 Jan 2006 07:44:01 -0700, "RG" wrote:

I was using some HP photo editing software that came with the camera ...
when you want to downsize a image file it offers two sizes - one
recommended for e-mail and one recommended for images for a web page.
Then, after selecting one of these, it offers a choice of decreasing it by
pixels or by percent of original. This is the part I am not sure about.
I'll try both and see if I can determine the difference, if any.
Shouldn't be any difference. Reducing a 3000X2000 image to a specified
1500X1000 pixels should give the exact same result as a request to reduce
the image by 50%, within the same program. Same resizing and resampling
algorhythms should be used to get there.

More advanced programs such as Photoshop and Paint Shop Pro give you a
choice of several reduction methods and optimizations. I use Irfan
view also, and it does a pretty crude job of resizing, and the
resulting file size is always much larger than those produced by more
sophisticated programs.

Irfanview is mostly useful as a quick viewer when you want to go
through a folder of photos. It's not really intended as an editor.


Commodore Joe Redcloud©
With Irfanview, you can make the file size as small as you want.
You are not understanding the issue. If I take a 1 MB file that is
1200 x 1200 and reduce it to 600x600 in both programs, the resulting
files will be vastly different in size. Irfanview is a handy viewer
and I use it all the time, but it was never intended as an editor, and
that portion of it is very crude.




Commodore Joe Redcloud©

I just resized a 3.74mb (50% reduction) pic in Irfanview with a resulting
filesize of 1.22mb. The same thing in Photoshop Elements resulted in a file
size of 1.629mb. Both were resized at the highest jpg quality.

Something else is going on here besides just the software being used. If I
reduce the dimensions by 50%, I'd expect the file size to be about 25% of
the original. Irfanview is closer to the expectation.
--
John H



I love it. Keep it up! Maybe it is a 50% reduction in file size, not a
50% reduction in real estate. Maybe not. And you do know what happens
every time you save a *.jpg file, right? It just keeps on compressing
itself.

What is it you love, Harry?
--
John H

******Have a spectacular day!******

On Mon, 23 Jan 2006 22:04:15 GMT, Commodore Joe Redcloud
wrote:

On Mon, 23 Jan 2006 16:01:19 -0500, JohnH wrote:

On Mon, 23 Jan 2006 20:47:38 GMT, Commodore Joe Redcloud©
wrote:

On Mon, 23 Jan 2006 15:42:28 -0500, JohnH wrote:

On Mon, 23 Jan 2006 15:08:11 GMT, Commodore Joe Redcloud©
wrote:

On Mon, 23 Jan 2006 07:44:01 -0700, "RG" wrote:



I was using some HP photo editing software that came with the camera ...
when you want to downsize a image file it offers two sizes - one
recommended for e-mail and one recommended for images for a web page.
Then, after selecting one of these, it offers a choice of decreasing it by
pixels or by percent of original. This is the part I am not sure about.
I'll try both and see if I can determine the difference, if any.

Shouldn't be any difference. Reducing a 3000X2000 image to a specified
1500X1000 pixels should give the exact same result as a request to reduce
the image by 50%, within the same program. Same resizing and resampling
algorhythms should be used to get there.


More advanced programs such as Photoshop and Paint Shop Pro give you a
choice of several reduction methods and optimizations. I use Irfan
view also, and it does a pretty crude job of resizing, and the
resulting file size is always much larger than those produced by more
sophisticated programs.

Irfanview is mostly useful as a quick viewer when you want to go
through a folder of photos. It's not really intended as an editor.


Commodore Joe Redcloud©

With Irfanview, you can make the file size as small as you want.

You are not understanding the issue. If I take a 1 MB file that is
1200 x 1200 and reduce it to 600x600 in both programs, the resulting
files will be vastly different in size. Irfanview is a handy viewer
and I use it all the time, but it was never intended as an editor, and
that portion of it is very crude.




Commodore Joe Redcloud©

I just resized a 3.74mb (50% reduction) pic in Irfanview with a resulting
filesize of 1.22mb. The same thing in Photoshop Elements resulted in a file
size of 1.629mb. Both were resized at the highest jpg quality.

Something else is going on here besides just the software being used. If I
reduce the dimensions by 50%, I'd expect the file size to be about 25% of
the original. Irfanview is closer to the expectation.

I have never used Photoshop Elements. As I understand it, it is a stripped down
version of Photoshop. My comparison is between Irfanview and Paint Shop Pro, and
the difference is substantial.


Commodore Joe Redcloud

What's strange is that Irfanview is making a larger file than Paintshop
Pro, but a smaller file than Photoshop Elements.

When I did the experiment, I saved both at the highest quality possible. I
don't know what is causing the file size change. But, in my case Irfanview
is making a smaller file, not a larger one.
--
John H

******Have a spectacular day!******

"Eisboch" wrote in message
...

"Harry Krause" wrote in message
...


I love it. Keep it up! Maybe it is a 50% reduction in file size, not a
50% reduction in real estate. Maybe not. And you do know what happens
every time you save a *.jpg file, right? It just keeps on compressing
itself.

I noticed that many of the image programs offer a compression option when
saving .jpg files. You can select anything from "lots" of compression for
smaller files and low quality or "no" compression for high quality but
bigger file sizes. Are you suggesting that they become compressed anyway,
by default?

Eisboch

If you use Paint Shop Pro and save an image in its native format
(*.pspimage), it is "lossless". I bet Photo Shop and Elements are the same
way regarding their native format.

It is also correct that every time you save an image in the jpeg format,
even without compression, there is some amount of information lost.

There is supposedly a "lossless" jpeg format that I've never played with but
have read it's not completely as advertised.