[pdftex] jpgs in pdf problems

[Jens-Uwe Morawski]

On Wed, 5 Jun 2002 08:01:07 -0700 (PDT)
cris g <gcris80 at yahoo.com> wrote:

> Hi,
> 
> thank you that you answered so quick. I know that I
> was too subjective. Sorry ... ;)
> 
> I know too little things about images. The things are
> like this: I made a screen capture, I saved it as
> img1.jpg. Microsoft Editor (ME) says that it has 513
> pixels width and 230px height.

The pixel size is the only important size. Others
like pt, inch or cm are calculated based on a
assumed resolution.

> How can I make my image
> bigger but not to lost the quality. I make a new
> capture with a smaller resolution ?

screen captures are a little problematic, since
the image size depends on your display resolution.
If your application window spawns the half of the width
and height of your display and your display runs at
1024x768 pixels the your capture will always have
512x384 px.

If you now want include this image in your document
with width 4 inch and it should be printable on a
600 dpi printer then the image size should be about
1200x900 px. That is a resolution of 300px per inch,
but it should be enough for the printer to interpolate
missing pixels.
The only way i know, is to scale the image in a graphics
programm (The Gimp, PhotoShop). After scaling you
should blur the image in order to reduce the pixel-effect.

Best,
  Jens