Is pixel a dot ?

Following is a question from Image Signal Processing Book:

Determine the actual physical measurement in millimeters of an image with 1400 rectangular pixels and a resolution of 72 dpi.

Is pixel a dot ?
LVL 1
naseeamAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Devin BeckerDevOps InternCommented:
Naseeam,

Although commonly used as DPI(Dots Per Inch), what is typically meant when talking about resolution(like that of a screen) is PPI(Pixels Per Inch).

So for this specific question they probably mean PPI, instead of DPI, since the two are commonly used interchangeably.

Hopefully this will get you the info you need, but if not, please feel free to ask any follow up questions.

Devin Becker
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Joe Winograd, Fellow&MVEDeveloperCommented:
Hi Naseeam,
The terms pixel and dot are often used interchangeably, but they're not really the same. I recommend doing some reading at Wayne Fulton's excellent site, A few scanning tips. In particular, here are some must-read sections:

Photographic Resolution - How much can we scan?
Pixels, Printers, Video - What's With That?
What is a digital image anyway?

Here are other helpful articles on the subject:

PPI vs. DPI: what’s the difference?
How do pixels and DPI and resolution and picture size and file size all relate?
The 72 PPI Web Resolution Myth
JPEG Myths and Facts

Regards, Joe
0
naseeamAuthor Commented:
Fast response!
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Physics Optics

From novice to tech pro — start learning today.