Computer Graphics with Photoshop - Annoying Problems Working & Saving to GIF

Author

Annoying Problems Working & Saving to GIF

JAckASs

2006-07-10, 6:18 pm

This is an annoying problem I'd like for someone to explain to me, and
preferably solve.

Here's my problem:

I'm scanning several pages of text that I want another person to look
at and print out. I scan each page as follows:
B&W scan (1-bit) at 100% and 250 dpi.

Then I "Save" it as a GIF. I want resolution/print size FIXED so
anyone opening the file will have it print to the same size.

Yet, when I open the file in any program, it opens as either 96 ppi
(in MS Photo Editor) or 72 ppi (in CS2), and the print size at 100% is
obviously way larger than I want it to be.

WTF? (Pardon my French)

Why can't Photoshop create a specific ppi/print size GIF file of my
choosing?

When I open the file again, and go into Image...Image Size, uncheck
Resample Image, then change 72 ppi back to 250 to restore the print
size I want, and then close the file, Photoshop asks if I want to save
the changes I've made, and I say "YES" and either overwrite or rename;
still, when I reopen the file, it goes back to 72 ppi! So frustrating!

I'm choosing GIF over JPG because I don't want JPEG artifacts. GIF is
the right choice for plain, black-on-white text.

----------------------------------

A related, equally annoying problem with CS2 and all earlier versions
of Photoshop, is Photoshop's inability to rotate a 1-bit B&W image in
increments (using the measuring tool and Rotate...Arbitrary). What's
the big deal? In the free MS Office app Microsoft Photo Editor, I can
rotate a 1-bit image in 1-degree increments. But in Photoshop I
can't.

What's up with that?

Thanks
Joe

Tom Thomas

2006-07-10, 6:18 pm

JAckASs <noone@nowhere.com> wrote:

>This is an annoying problem I'd like for someone to explain to me, and
>preferably solve.
>
>Here's my problem:
>
>I'm scanning several pages of text that I want another person to look
>at and print out. I scan each page as follows:
>B&W scan (1-bit) at 100% and 250 dpi.
>
>Then I "Save" it as a GIF. I want resolution/print size FIXED so
>anyone opening the file will have it print to the same size.

You can't do that. The GIF file specification does not support print
resolution. It is going to print based on the number of pixels.
There is no such thing as DPI in the GIF file format. Why not use PDF
instead?

>Yet, when I open the file in any program, it opens as either 96 ppi
>(in MS Photo Editor) or 72 ppi (in CS2), and the print size at 100% is
>obviously way larger than I want it to be.

Yes. See above.

>Why can't Photoshop create a specific ppi/print size GIF file of my
>choosing?

Because the GIF format does not support it. It has nothing to do with
Photoshop.

>I'm choosing GIF over JPG because I don't want JPEG artifacts. GIF is
>the right choice for plain, black-on-white text.

Neither GIF nor JPG are really intended for print. They are
compressed formats intended for sending/viewing via computer where
file size is an issue.

------------------
Tom

Unsolicited advertisements cheerfully ignored.

tacit

2006-07-10, 6:18 pm

In article <lau2a2pnfi37j6r4d5reit8egt24hacn5i@4ax.com>,
JAckASs <noone@nowhere.com> wrote:

> Then I "Save" it as a GIF. I want resolution/print size FIXED so
> anyone opening the file will have it print to the same size.
>
> Yet, when I open the file in any program, it opens as either 96 ppi
> (in MS Photo Editor) or 72 ppi (in CS2), and the print size at 100% is
> obviously way larger than I want it to be.
>
> WTF? (Pardon my French)

Part of the GIF file format specification.

The GIF file format specification does not allow you to save resolution
information in pixels per inch. It simply isn't part of the spec; GIF
doesn't allow it. You can't do what you want to do using GIF.

Use TIFF or some other format instead.

--
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all at http://www.xeromag.com/franklin.html
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JAckASs

2006-07-10, 6:18 pm

On Tue, 27 Jun 2006 15:30:02 -0400, Tom Thomas <tom187@earthlink.net>
wrote:

>JAckASs <noone@nowhere.com> wrote:
>
>
>You can't do that. The GIF file specification does not support print
>resolution. It is going to print based on the number of pixels.
>There is no such thing as DPI in the GIF file format. Why not use PDF
>instead?

Thanks, I had no idea that GIF didn't support print resolution.

You're right, PDF would be a better choice.

Thanks again and to tacit (PDF would work better than TIFF, since
there are 3 pages I want to send, one .pdf would be easier.)