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

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
>
>

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
>>
>>
>
>

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."

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:G-(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."

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:G-(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."

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
> >>
> >>
> >
> >
>
>

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:G-(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."
>
>

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
>> >>
>> >>
>> >
>> >
>>
>>
>
>