Re: Graphics dpi for .pdf

Subject: Re: Graphics dpi for .pdf
From: Max Wyss <prodok -at- prodok -dot- ch>
To: "Missy Phillips" <dictionary_behage -at- hotmail -dot- com>
Date: Tue, 19 Sep 2000 10:10:35 +0200

Missy Phillips,

it seems to be screenshot time all over the place <g>. Here is what I just sent yesterday on another mailing list (Acrobat Talk) about creating screenshots.

There are a few things to keep in mind when it comes to screenshots.

First, your screenshots are bitmap images, which means that they have a certain size at a given resolution. At this, and only at this plus mulitples of that resolution, they are displayed good. At all other resolutions, the Acrobat viewer component has to scale and to calculate the best possible appearance.

Second, Acrobat works internally at 72 dpi; Windows works internally at 96 dpi.

Third, it depends a lot on the file formats you are using for your screenshots.

Fourth, scaling in the layout software will add additonal problems.

So, let's look at the procedure to create an optimum quality for screenshots. As you have Photoshop available, you have a good image processing tool at hand.

1. Take the screenshot. It might most likely be in the BMP or TIFF format.

2. Decide on the size in mm/inches the screenshot shall get in the final product (if printed). Get the resolution of the output device you will use. If it is Acrobat, it will be 72 dpi. Calculate the size of the final image in _pixels_ (resolution x size).

3. Open the screenshot in Photoshop. Make the color adjustments etc. and crop it if needed.

4. Scale the image to the final size in pixels.

5. Set the resolution to 72 dpi.

6. As it is a screenshot, you will not have that many colors, so that you now can start reducing the colors. Switch to "Indexed" mode, adaptive palette, 256 colors. Switch back to 24 bit color. Again, switch back to "indexed", but this time with the exact number of colors selected. Your screenshot is now reduced in colors to the minimum.

7. Save the image as GIF or TIFF. Never ever save a screenshot as JPEG (unless it is actually a photograph, consisting of textures with low contrast).

8. Place the screenshot in your layout software. As you are using MessyWord, you might have to fiddle a bit in order to make sure that the image gets imported and does not get any further manipulation.

NEVER, EVER, SCALE a screenshot when you imported it like that.

9. Save the document and create the PostScript file for processing in Distiller.

10. In the Distiller Job options set the compression for color images to 8-bit ZIP. Do not set it to any kind of JPEG compression, as this will destroy all your previous efforts. You will get good compression rates, as you do have screenshots.

11. Create the PDF, and your screenshots should look decent.

Hope, this can help.

Max Wyss
PRODOK Engineering
Low Paper workflows, Smart documents, PDF forms
CH-8906 Bonstetten, Switzerland

Fax: +41 1 700 20 37
e-mail: mailto:prodok -at- prodok -dot- ch

[ Building Bridges for Information ]


Hi. I'm wondering if anyone knows what dpi to save a screen capture at if the capture will be ported to a .pdf and sent with the sw that way?

Previous by Author: Re: Desktop publishing software?
Next by Author: Re: web authoring questions (dhtml v. javascript)
Previous by Thread: Graphics dpi for .pdf
Next by Thread: Need urgent help

What this post helpful? Share it with friends and colleagues:

Sponsored Ads

Sponsored Ads