PC Review


Reply
 
 
Daz
Guest
Posts: n/a
 
      10th Mar 2006
If I open a jpg, that I have downloaded from my camera, using Photo Editor
(or Paint Shop Pro or Aftershot), and then save it at best quality, to give
a photo with the original quality, the resulting file size is about four
times the original jpg size.

If I increase the compression, so that the file size is the same as the
original, then the quality is reduced.

Can anyone explain this phenomenon?

Daz


 
Reply With Quote
 
 
 
 
Yves Alarie
Guest
Posts: n/a
 
      10th Mar 2006
1. What kind of camera do you have?
2. What level of jpg compression do you use in your camera?

"Daz" <daz@nopc> wrote in message
news:(E-Mail Removed)...
> If I open a jpg, that I have downloaded from my camera, using Photo Editor
> (or Paint Shop Pro or Aftershot), and then save it at best quality, to

give
> a photo with the original quality, the resulting file size is about four
> times the original jpg size.
>
> If I increase the compression, so that the file size is the same as the
> original, then the quality is reduced.
>
> Can anyone explain this phenomenon?
>
> Daz
>
>



 
Reply With Quote
 
 
 
 
Daz
Guest
Posts: n/a
 
      11th Mar 2006
1. I have a Fuji S304.
2. All that I can find, from the manual, is that the picture format is JPEG,
Exif Ver.2.2. Does this tell you what compression my camera is using?


"Yves Alarie" <rd50@@pitt.edu> wrote in message
news:%(E-Mail Removed)...
> 1. What kind of camera do you have?
> 2. What level of jpg compression do you use in your camera?
>
> "Daz" <daz@nopc> wrote in message
> news:(E-Mail Removed)...
>> If I open a jpg, that I have downloaded from my camera, using Photo
>> Editor
>> (or Paint Shop Pro or Aftershot), and then save it at best quality, to

> give
>> a photo with the original quality, the resulting file size is about four
>> times the original jpg size.
>>
>> If I increase the compression, so that the file size is the same as the
>> original, then the quality is reduced.
>>
>> Can anyone explain this phenomenon?
>>
>> Daz
>>
>>

>
>



 
Reply With Quote
 
Michael J. Mahon
Guest
Posts: n/a
 
      11th Mar 2006
Daz wrote:
> If I open a jpg, that I have downloaded from my camera, using Photo Editor
> (or Paint Shop Pro or Aftershot), and then save it at best quality, to give
> a photo with the original quality, the resulting file size is about four
> times the original jpg size.
>
> If I increase the compression, so that the file size is the same as the
> original, then the quality is reduced.
>
> Can anyone explain this phenomenon?


It sounds like PSP's JPEG compressor is not doing as good a job as
your camera's compressor.

This is a little peculiar, since JPEG is defined by particular
compression and decompression algorithms.

Maybe someone is taking shortcuts...or you are selecting different
levels of optimization or interlaced/progressive when compressing.

Try some more experiments and try to find what PSP compression
degree is just indistinguishable from the camera's version.

FWIW, I use Photoshop, and I find that I can usually preserve all
the quality of a photo at about half the camera's "HQ" compression
file size.

-michael

Home page: http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it is seriously underused."
 
Reply With Quote
 
Daz
Guest
Posts: n/a
 
      11th Mar 2006
Thank you for your advice Michael. I will experiment a bit more, as you
suggest.

Vic

"Michael J. Mahon" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Daz wrote:
>> If I open a jpg, that I have downloaded from my camera, using Photo
>> Editor (or Paint Shop Pro or Aftershot), and then save it at best
>> quality, to give a photo with the original quality, the resulting file
>> size is about four times the original jpg size.
>>
>> If I increase the compression, so that the file size is the same as the
>> original, then the quality is reduced.
>>
>> Can anyone explain this phenomenon?

>
> It sounds like PSP's JPEG compressor is not doing as good a job as
> your camera's compressor.
>
> This is a little peculiar, since JPEG is defined by particular
> compression and decompression algorithms.
>
> Maybe someone is taking shortcuts...or you are selecting different
> levels of optimization or interlaced/progressive when compressing.
>
> Try some more experiments and try to find what PSP compression
> degree is just indistinguishable from the camera's version.
>
> FWIW, I use Photoshop, and I find that I can usually preserve all
> the quality of a photo at about half the camera's "HQ" compression
> file size.
>
> -michael
>
> Home page: http://members.aol.com/MJMahon/
>
> "The wastebasket is our most important design
> tool--and it is seriously underused."



 
Reply With Quote
 
Yves Alarie
Guest
Posts: n/a
 
      11th Mar 2006
Your camera has two level of compression: fine and normal. Obviously fine is
better.
I have Paint Shop Pro X.
When you open a photo with it and you Save As, the default compression is
set at 20. If you use this, the file size will be about the same as the
original. If you set this down to 1, less compression, the file size will be
about 4 to 5 times the original. However, there is nothing to gain by doing
this.
"Michael J. Mahon" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Daz wrote:
> > If I open a jpg, that I have downloaded from my camera, using Photo

Editor
> > (or Paint Shop Pro or Aftershot), and then save it at best quality, to

give
> > a photo with the original quality, the resulting file size is about four
> > times the original jpg size.
> >
> > If I increase the compression, so that the file size is the same as the
> > original, then the quality is reduced.
> >
> > Can anyone explain this phenomenon?

>
> It sounds like PSP's JPEG compressor is not doing as good a job as
> your camera's compressor.
>
> This is a little peculiar, since JPEG is defined by particular
> compression and decompression algorithms.
>
> Maybe someone is taking shortcuts...or you are selecting different
> levels of optimization or interlaced/progressive when compressing.
>
> Try some more experiments and try to find what PSP compression
> degree is just indistinguishable from the camera's version.
>
> FWIW, I use Photoshop, and I find that I can usually preserve all
> the quality of a photo at about half the camera's "HQ" compression
> file size.
>
> -michael
>
> Home page: http://members.aol.com/MJMahon/
>
> "The wastebasket is our most important design
> tool--and it is seriously underused."



 
Reply With Quote
 
Yves Alarie
Guest
Posts: n/a
 
      11th Mar 2006
Your camera has two level of compression: fine and normal. Obviously fine is
better.
I have Paint Shop Pro X.
When you open a photo with it and you Save As, the default compression is
set at 20. If you use this, the file size will be about the same as the
original. If you set this down to 1, less compression, the file size will be
about 4 to 5 times the original. However, there is nothing to gain by doing
this.

"Daz" <daz@nopc> wrote in message
news:(E-Mail Removed)...
> 1. I have a Fuji S304.
> 2. All that I can find, from the manual, is that the picture format is

JPEG,
> Exif Ver.2.2. Does this tell you what compression my camera is using?
>
>
> "Yves Alarie" <rd50@@pitt.edu> wrote in message
> news:%(E-Mail Removed)...
> > 1. What kind of camera do you have?
> > 2. What level of jpg compression do you use in your camera?
> >
> > "Daz" <daz@nopc> wrote in message
> > news:(E-Mail Removed)...
> >> If I open a jpg, that I have downloaded from my camera, using Photo
> >> Editor
> >> (or Paint Shop Pro or Aftershot), and then save it at best quality, to

> > give
> >> a photo with the original quality, the resulting file size is about

four
> >> times the original jpg size.
> >>
> >> If I increase the compression, so that the file size is the same as the
> >> original, then the quality is reduced.
> >>
> >> Can anyone explain this phenomenon?
> >>
> >> Daz
> >>
> >>

> >
> >

>
>



 
Reply With Quote
 
Yves Alarie
Guest
Posts: n/a
 
      11th Mar 2006
Sorry. Wrong person!

"Yves Alarie" <rd50@@pitt.edu> wrote in message
news:(E-Mail Removed)...
> Your camera has two level of compression: fine and normal. Obviously fine

is
> better.
> I have Paint Shop Pro X.
> When you open a photo with it and you Save As, the default compression is
> set at 20. If you use this, the file size will be about the same as the
> original. If you set this down to 1, less compression, the file size will

be
> about 4 to 5 times the original. However, there is nothing to gain by

doing
> this.
> "Michael J. Mahon" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > Daz wrote:
> > > If I open a jpg, that I have downloaded from my camera, using Photo

> Editor
> > > (or Paint Shop Pro or Aftershot), and then save it at best quality, to

> give
> > > a photo with the original quality, the resulting file size is about

four
> > > times the original jpg size.
> > >
> > > If I increase the compression, so that the file size is the same as

the
> > > original, then the quality is reduced.
> > >
> > > Can anyone explain this phenomenon?

> >
> > It sounds like PSP's JPEG compressor is not doing as good a job as
> > your camera's compressor.
> >
> > This is a little peculiar, since JPEG is defined by particular
> > compression and decompression algorithms.
> >
> > Maybe someone is taking shortcuts...or you are selecting different
> > levels of optimization or interlaced/progressive when compressing.
> >
> > Try some more experiments and try to find what PSP compression
> > degree is just indistinguishable from the camera's version.
> >
> > FWIW, I use Photoshop, and I find that I can usually preserve all
> > the quality of a photo at about half the camera's "HQ" compression
> > file size.
> >
> > -michael
> >
> > Home page: http://members.aol.com/MJMahon/
> >
> > "The wastebasket is our most important design
> > tool--and it is seriously underused."

>
>



 
Reply With Quote
 
Daz
Guest
Posts: n/a
 
      13th Mar 2006
Thanks alot. I think that I am now starting to understand the JPEG
compression process.

Vic


"Yves Alarie" <rd50@@pitt.edu> wrote in message
news:%(E-Mail Removed)...
> Your camera has two level of compression: fine and normal. Obviously fine
> is
> better.
> I have Paint Shop Pro X.
> When you open a photo with it and you Save As, the default compression is
> set at 20. If you use this, the file size will be about the same as the
> original. If you set this down to 1, less compression, the file size will
> be
> about 4 to 5 times the original. However, there is nothing to gain by
> doing
> this.
>
> "Daz" <daz@nopc> wrote in message
> news:(E-Mail Removed)...
>> 1. I have a Fuji S304.
>> 2. All that I can find, from the manual, is that the picture format is

> JPEG,
>> Exif Ver.2.2. Does this tell you what compression my camera is using?
>>
>>
>> "Yves Alarie" <rd50@@pitt.edu> wrote in message
>> news:%(E-Mail Removed)...
>> > 1. What kind of camera do you have?
>> > 2. What level of jpg compression do you use in your camera?
>> >
>> > "Daz" <daz@nopc> wrote in message
>> > news:(E-Mail Removed)...
>> >> If I open a jpg, that I have downloaded from my camera, using Photo
>> >> Editor
>> >> (or Paint Shop Pro or Aftershot), and then save it at best quality, to
>> > give
>> >> a photo with the original quality, the resulting file size is about

> four
>> >> times the original jpg size.
>> >>
>> >> If I increase the compression, so that the file size is the same as
>> >> the
>> >> original, then the quality is reduced.
>> >>
>> >> Can anyone explain this phenomenon?
>> >>
>> >> Daz
>> >>
>> >>
>> >
>> >

>>
>>

>
>



 
Reply With Quote
 
 
 
Reply

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
SP2 Problem - Blocks saving JPGs and GIFs - Only allows BMP saves steven@nospam.com Windows XP Basics 5 10th Oct 2004 08:31 AM
problem saving jpgs dalamar Windows XP Photos 1 15th Apr 2004 06:22 AM
Digitized JPGs on IE...can't see JPGs properly phil Windows XP Internet Explorer 0 13th Dec 2003 07:52 AM
Saving jpgs timw_mk Windows XP Help 2 25th Oct 2003 11:03 PM
Saving images from IE as JPGs not BMPs... Frank McMahon Windows XP Photos 1 14th Sep 2003 05:34 PM


Features
 

Advertising
 

Newsgroups
 


All times are GMT +1. The time now is 10:35 AM.