Computer Graphics with Photoshop - Confusing File sizes

Author

Confusing File sizes

Glenis

2007-02-17, 6:15 pm

I opened the same JPG image in 3 different graphics apps and saved it
in various formats.
Here's what I found:

Original JPG size: 1033kb

Photoshop CS2
Saved as PNG. Size: 2102kb
Saved as TIFF. Size: 5648kb

Photoshop 7
Saved as PNG. Size: 2226kb
Saved as TIFF. Size: 7485kb

Paint Shop Pro 8
Saved as PNG. Size: 2207kb
Saved as TIFF. Size: 5627kb

All PNGs were saved as non-interlaced & non-optimized
All TIFFs were saved as uncompressed

Could someone explain this

tacit

2007-02-17, 10:14 pm

In article <45d7482b$0$8750$ed2619ec@ptn-nntp-reader02.plus.net>,
Glenis <gh@here.co.uk> wrote:

> Photoshop CS2
> Saved as PNG. Size: 2102kb
> Saved as TIFF. Size: 5648kb
>
> Photoshop 7
> Saved as PNG. Size: 2226kb
> Saved as TIFF. Size: 7485kb
>
> Paint Shop Pro 8
> Saved as PNG. Size: 2207kb
> Saved as TIFF. Size: 5627kb
>
> All PNGs were saved as non-interlaced & non-optimized
> All TIFFs were saved as uncompressed

Looks like one of the TIFs was saved with layers.

Also, Photoshop will, unless you specify otherwise, save files with
embedded thumbnails, previews, and embedded color profiles. This will
make the file size slightly bigger.

--
Photography, kink, polyamory, shareware, and more: all at
http://www.xeromag.com/franklin.html

Glenis

2007-02-17, 10:14 pm

tacit wrote:
> In article <45d7482b$0$8750$ed2619ec@ptn-nntp-reader02.plus.net>,
> Glenis <gh@here.co.uk> wrote:
>
>
> Looks like one of the TIFs was saved with layers.
>
> Also, Photoshop will, unless you specify otherwise, save files with
> embedded thumbnails, previews, and embedded color profiles. This will
> make the file size slightly bigger.
>

That's the odd thing. I simply opened the the same JPG file in each app
and then saved it to a different format

tacit

2007-02-17, 10:14 pm

In article <45d797fb$0$8752$ed2619ec@ptn-nntp-reader02.plus.net>,
Glenis <gh@here.co.uk> wrote:

> That's the odd thing. I simply opened the the same JPG file in each app
> and then saved it to a different format

Correct.

By default, if you just install different apps and leave the preferences
untouched, they will do different things.

Photoshop, by default, will save a thumbnail, a preview, and a color
profile in every file you save. Open a file and save it again in
Photoshop, and if it did not have those things to begin with, it will.
Hence, its size will increase slightly.

By default, if you save a layered file in Photoshop, then it will also
save a composite, flattened copy of the file, increasing its size.

Hence, it pays to look at and understand the preferences of your
graphics apps, and to understand which options are appropriate for your
needs.

--
Photography, kink, polyamory, shareware, and more: all at
http://www.xeromag.com/franklin.html

Glenis

2007-02-18, 10:14 pm

OK thanks, I'll check that out

tacit wrote:
> In article <45d797fb$0$8752$ed2619ec@ptn-nntp-reader02.plus.net>,
> Glenis <gh@here.co.uk> wrote:
>
>
> Correct.
>
> By default, if you just install different apps and leave the preferences
> untouched, they will do different things.
>
> Photoshop, by default, will save a thumbnail, a preview, and a color
> profile in every file you save. Open a file and save it again in
> Photoshop, and if it did not have those things to begin with, it will.
> Hence, its size will increase slightly.
>
> By default, if you save a layered file in Photoshop, then it will also
> save a composite, flattened copy of the file, increasing its size.
>
> Hence, it pays to look at and understand the preferences of your
> graphics apps, and to understand which options are appropriate for your
> needs.
>