TechWhirl (TECHWR-L) is a resource for technical writing and technical communications professionals of all experience levels and in all industries to share their experiences and acquire information.
For two decades, technical communicators have turned to TechWhirl to ask and answer questions about the always-changing world of technical communications, such as tools, skills, career paths, methodologies, and emerging industries. The TechWhirl Archives and magazine, created for, by and about technical writers, offer a wealth of knowledge to everyone with an interest in any aspect of technical communications.
Subject:Re: Resolution of graphics for printed docs From:"Chris Christner" <cchris -at- toptechwriter -dot- us> To:"TECHWR-L" <techwr-l -at- lists -dot- techwr-l -dot- com> Date:Wed, 5 Oct 2005 10:02:33 -0600
Hi TW,
> Chris' post contains one, possibly more errors, such as the idea that
> changing resolution increases file size. Changing resolution has no
> effect on file size. Adding pixels will change file size. Adding color
> will change file size. Changing file format will change file size.
> Changing resolution does not.
>
> I skipped the rest of what he wrote, so just this note of caution.
Ohhkay, I just did this experiment using the same screencap of a dialog
box I mentioned in my previous post, the dimensions were:
Pixel Dimensions: 505 W x 314 H pixels
Print Size: 7.028 W x 4.361 H inches at 72 ppi
The file size when saved in Photoshop format is 152 K
After only doubling the resolution to 144 ppi (with bicubic resampling
turned on), the file size jumps to 784 K! Details:
Pixel Dimensions: 1012 W x 628 H pixels
Print Size: 7.028 W x 4.361 H inches at 144 ppi
The file size when saved in Photoshop format is 784 K
Notice that the pixel dimensions changed but the physical size remained
the same. The resampling process added more pixels to the image,
increasing its file size.
If you repeat the test but this time turn bicubic resampling off, here's
what you get:
Pixel Dimensions: 506 W x 314 H pixels
Print Size: 3.514 W x 2.181 H inches at 144 ppi
The file size when saved in Photoshop format has stayed at 152 K, but
that's because the print size was cut in half! This happens because
Photoshop isn't being allowed to use resampling to create more pixels, so
it's forced to size the image smaller to increase resolution, which is why
the file size doesn't increase.
So you can't add more resolution without increasing file size or reducing
image dimensions.
--Chris
P.S. This is what your message looks like at TECHWR-L online in Mozilla on
a Mac:
Now Shipping -- WebWorks ePublisher Pro for Word! Easily create online
Help. And online anything else. Redesigned interface with a new
project-based workflow. Try it today! http://www.webworks.com/techwr-l
Doc-To-Help 2005 converts RoboHelp files with one click. Author with Word or any HTML editor. Visit our site to see a conversion demo movie and learn more. http://www.componentone.com/TECHWRL/DocToHelp2005
---
You are currently subscribed to techwr-l as:
archiver -at- techwr-l -dot- com
To unsubscribe send a blank email to leave-techwr-l-obscured -at- lists -dot- techwr-l -dot- com
Send administrative questions to lisa -at- techwr-l -dot- com -dot- Visit http://www.techwr-l.com/techwhirl/ for more resources and info.
